[PATCH] USB: khubd: use kthread API
[linux-2.6.git] / drivers / usb / core / hub.c
1 /*
2  * USB hub driver.
3  *
4  * (C) Copyright 1999 Linus Torvalds
5  * (C) Copyright 1999 Johannes Erdfelt
6  * (C) Copyright 1999 Gregory P. Smith
7  * (C) Copyright 2001 Brad Hards (bhards@bigpond.net.au)
8  *
9  */
10
11 #include <linux/config.h>
12 #ifdef CONFIG_USB_DEBUG
13         #define DEBUG
14 #else
15         #undef DEBUG
16 #endif
17 #include <linux/kernel.h>
18 #include <linux/errno.h>
19 #include <linux/module.h>
20 #include <linux/moduleparam.h>
21 #include <linux/completion.h>
22 #include <linux/sched.h>
23 #include <linux/list.h>
24 #include <linux/slab.h>
25 #include <linux/smp_lock.h>
26 #include <linux/ioctl.h>
27 #include <linux/usb.h>
28 #include <linux/usbdevice_fs.h>
29 #include <linux/kthread.h>
30
31 #include <asm/semaphore.h>
32 #include <asm/uaccess.h>
33 #include <asm/byteorder.h>
34
35 #include "usb.h"
36 #include "hcd.h"
37 #include "hub.h"
38
39 /* Protect struct usb_device->state and ->children members
40  * Note: Both are also protected by ->serialize, except that ->state can
41  * change to USB_STATE_NOTATTACHED even when the semaphore isn't held. */
42 static DEFINE_SPINLOCK(device_state_lock);
43
44 /* khubd's worklist and its lock */
45 static DEFINE_SPINLOCK(hub_event_lock);
46 static LIST_HEAD(hub_event_list);       /* List of hubs needing servicing */
47
48 /* Wakes up khubd */
49 static DECLARE_WAIT_QUEUE_HEAD(khubd_wait);
50
51 static struct task_struct *khubd_task;
52
53 /* cycle leds on hubs that aren't blinking for attention */
54 static int blinkenlights = 0;
55 module_param (blinkenlights, bool, S_IRUGO);
56 MODULE_PARM_DESC (blinkenlights, "true to cycle leds on hubs");
57
58 /*
59  * As of 2.6.10 we introduce a new USB device initialization scheme which
60  * closely resembles the way Windows works.  Hopefully it will be compatible
61  * with a wider range of devices than the old scheme.  However some previously
62  * working devices may start giving rise to "device not accepting address"
63  * errors; if that happens the user can try the old scheme by adjusting the
64  * following module parameters.
65  *
66  * For maximum flexibility there are two boolean parameters to control the
67  * hub driver's behavior.  On the first initialization attempt, if the
68  * "old_scheme_first" parameter is set then the old scheme will be used,
69  * otherwise the new scheme is used.  If that fails and "use_both_schemes"
70  * is set, then the driver will make another attempt, using the other scheme.
71  */
72 static int old_scheme_first = 0;
73 module_param(old_scheme_first, bool, S_IRUGO | S_IWUSR);
74 MODULE_PARM_DESC(old_scheme_first,
75                  "start with the old device initialization scheme");
76
77 static int use_both_schemes = 1;
78 module_param(use_both_schemes, bool, S_IRUGO | S_IWUSR);
79 MODULE_PARM_DESC(use_both_schemes,
80                 "try the other device initialization scheme if the "
81                 "first one fails");
82
83
84 #ifdef  DEBUG
85 static inline char *portspeed (int portstatus)
86 {
87         if (portstatus & (1 << USB_PORT_FEAT_HIGHSPEED))
88                 return "480 Mb/s";
89         else if (portstatus & (1 << USB_PORT_FEAT_LOWSPEED))
90                 return "1.5 Mb/s";
91         else
92                 return "12 Mb/s";
93 }
94 #endif
95
96 /* Note that hdev or one of its children must be locked! */
97 static inline struct usb_hub *hdev_to_hub(struct usb_device *hdev)
98 {
99         return usb_get_intfdata(hdev->actconfig->interface[0]);
100 }
101
102 /* USB 2.0 spec Section 11.24.4.5 */
103 static int get_hub_descriptor(struct usb_device *hdev, void *data, int size)
104 {
105         int i, ret;
106
107         for (i = 0; i < 3; i++) {
108                 ret = usb_control_msg(hdev, usb_rcvctrlpipe(hdev, 0),
109                         USB_REQ_GET_DESCRIPTOR, USB_DIR_IN | USB_RT_HUB,
110                         USB_DT_HUB << 8, 0, data, size,
111                         USB_CTRL_GET_TIMEOUT);
112                 if (ret >= (USB_DT_HUB_NONVAR_SIZE + 2))
113                         return ret;
114         }
115         return -EINVAL;
116 }
117
118 /*
119  * USB 2.0 spec Section 11.24.2.1
120  */
121 static int clear_hub_feature(struct usb_device *hdev, int feature)
122 {
123         return usb_control_msg(hdev, usb_sndctrlpipe(hdev, 0),
124                 USB_REQ_CLEAR_FEATURE, USB_RT_HUB, feature, 0, NULL, 0, 1000);
125 }
126
127 /*
128  * USB 2.0 spec Section 11.24.2.2
129  */
130 static int clear_port_feature(struct usb_device *hdev, int port1, int feature)
131 {
132         return usb_control_msg(hdev, usb_sndctrlpipe(hdev, 0),
133                 USB_REQ_CLEAR_FEATURE, USB_RT_PORT, feature, port1,
134                 NULL, 0, 1000);
135 }
136
137 /*
138  * USB 2.0 spec Section 11.24.2.13
139  */
140 static int set_port_feature(struct usb_device *hdev, int port1, int feature)
141 {
142         return usb_control_msg(hdev, usb_sndctrlpipe(hdev, 0),
143                 USB_REQ_SET_FEATURE, USB_RT_PORT, feature, port1,
144                 NULL, 0, 1000);
145 }
146
147 /*
148  * USB 2.0 spec Section 11.24.2.7.1.10 and table 11-7
149  * for info about using port indicators
150  */
151 static void set_port_led(
152         struct usb_hub *hub,
153         int port1,
154         int selector
155 )
156 {
157         int status = set_port_feature(hub->hdev, (selector << 8) | port1,
158                         USB_PORT_FEAT_INDICATOR);
159         if (status < 0)
160                 dev_dbg (hub->intfdev,
161                         "port %d indicator %s status %d\n",
162                         port1,
163                         ({ char *s; switch (selector) {
164                         case HUB_LED_AMBER: s = "amber"; break;
165                         case HUB_LED_GREEN: s = "green"; break;
166                         case HUB_LED_OFF: s = "off"; break;
167                         case HUB_LED_AUTO: s = "auto"; break;
168                         default: s = "??"; break;
169                         }; s; }),
170                         status);
171 }
172
173 #define LED_CYCLE_PERIOD        ((2*HZ)/3)
174
175 static void led_work (void *__hub)
176 {
177         struct usb_hub          *hub = __hub;
178         struct usb_device       *hdev = hub->hdev;
179         unsigned                i;
180         unsigned                changed = 0;
181         int                     cursor = -1;
182
183         if (hdev->state != USB_STATE_CONFIGURED || hub->quiescing)
184                 return;
185
186         for (i = 0; i < hub->descriptor->bNbrPorts; i++) {
187                 unsigned        selector, mode;
188
189                 /* 30%-50% duty cycle */
190
191                 switch (hub->indicator[i]) {
192                 /* cycle marker */
193                 case INDICATOR_CYCLE:
194                         cursor = i;
195                         selector = HUB_LED_AUTO;
196                         mode = INDICATOR_AUTO;
197                         break;
198                 /* blinking green = sw attention */
199                 case INDICATOR_GREEN_BLINK:
200                         selector = HUB_LED_GREEN;
201                         mode = INDICATOR_GREEN_BLINK_OFF;
202                         break;
203                 case INDICATOR_GREEN_BLINK_OFF:
204                         selector = HUB_LED_OFF;
205                         mode = INDICATOR_GREEN_BLINK;
206                         break;
207                 /* blinking amber = hw attention */
208                 case INDICATOR_AMBER_BLINK:
209                         selector = HUB_LED_AMBER;
210                         mode = INDICATOR_AMBER_BLINK_OFF;
211                         break;
212                 case INDICATOR_AMBER_BLINK_OFF:
213                         selector = HUB_LED_OFF;
214                         mode = INDICATOR_AMBER_BLINK;
215                         break;
216                 /* blink green/amber = reserved */
217                 case INDICATOR_ALT_BLINK:
218                         selector = HUB_LED_GREEN;
219                         mode = INDICATOR_ALT_BLINK_OFF;
220                         break;
221                 case INDICATOR_ALT_BLINK_OFF:
222                         selector = HUB_LED_AMBER;
223                         mode = INDICATOR_ALT_BLINK;
224                         break;
225                 default:
226                         continue;
227                 }
228                 if (selector != HUB_LED_AUTO)
229                         changed = 1;
230                 set_port_led(hub, i + 1, selector);
231                 hub->indicator[i] = mode;
232         }
233         if (!changed && blinkenlights) {
234                 cursor++;
235                 cursor %= hub->descriptor->bNbrPorts;
236                 set_port_led(hub, cursor + 1, HUB_LED_GREEN);
237                 hub->indicator[cursor] = INDICATOR_CYCLE;
238                 changed++;
239         }
240         if (changed)
241                 schedule_delayed_work(&hub->leds, LED_CYCLE_PERIOD);
242 }
243
244 /* use a short timeout for hub/port status fetches */
245 #define USB_STS_TIMEOUT         1000
246 #define USB_STS_RETRIES         5
247
248 /*
249  * USB 2.0 spec Section 11.24.2.6
250  */
251 static int get_hub_status(struct usb_device *hdev,
252                 struct usb_hub_status *data)
253 {
254         int i, status = -ETIMEDOUT;
255
256         for (i = 0; i < USB_STS_RETRIES && status == -ETIMEDOUT; i++) {
257                 status = usb_control_msg(hdev, usb_rcvctrlpipe(hdev, 0),
258                         USB_REQ_GET_STATUS, USB_DIR_IN | USB_RT_HUB, 0, 0,
259                         data, sizeof(*data), USB_STS_TIMEOUT);
260         }
261         return status;
262 }
263
264 /*
265  * USB 2.0 spec Section 11.24.2.7
266  */
267 static int get_port_status(struct usb_device *hdev, int port1,
268                 struct usb_port_status *data)
269 {
270         int i, status = -ETIMEDOUT;
271
272         for (i = 0; i < USB_STS_RETRIES && status == -ETIMEDOUT; i++) {
273                 status = usb_control_msg(hdev, usb_rcvctrlpipe(hdev, 0),
274                         USB_REQ_GET_STATUS, USB_DIR_IN | USB_RT_PORT, 0, port1,
275                         data, sizeof(*data), USB_STS_TIMEOUT);
276         }
277         return status;
278 }
279
280 static void kick_khubd(struct usb_hub *hub)
281 {
282         unsigned long   flags;
283
284         spin_lock_irqsave(&hub_event_lock, flags);
285         if (list_empty(&hub->event_list)) {
286                 list_add_tail(&hub->event_list, &hub_event_list);
287                 wake_up(&khubd_wait);
288         }
289         spin_unlock_irqrestore(&hub_event_lock, flags);
290 }
291
292 void usb_kick_khubd(struct usb_device *hdev)
293 {
294         kick_khubd(hdev_to_hub(hdev));
295 }
296
297
298 /* completion function, fires on port status changes and various faults */
299 static void hub_irq(struct urb *urb, struct pt_regs *regs)
300 {
301         struct usb_hub *hub = (struct usb_hub *)urb->context;
302         int status;
303         int i;
304         unsigned long bits;
305
306         switch (urb->status) {
307         case -ENOENT:           /* synchronous unlink */
308         case -ECONNRESET:       /* async unlink */
309         case -ESHUTDOWN:        /* hardware going away */
310                 return;
311
312         default:                /* presumably an error */
313                 /* Cause a hub reset after 10 consecutive errors */
314                 dev_dbg (hub->intfdev, "transfer --> %d\n", urb->status);
315                 if ((++hub->nerrors < 10) || hub->error)
316                         goto resubmit;
317                 hub->error = urb->status;
318                 /* FALL THROUGH */
319         
320         /* let khubd handle things */
321         case 0:                 /* we got data:  port status changed */
322                 bits = 0;
323                 for (i = 0; i < urb->actual_length; ++i)
324                         bits |= ((unsigned long) ((*hub->buffer)[i]))
325                                         << (i*8);
326                 hub->event_bits[0] = bits;
327                 break;
328         }
329
330         hub->nerrors = 0;
331
332         /* Something happened, let khubd figure it out */
333         kick_khubd(hub);
334
335 resubmit:
336         if (hub->quiescing)
337                 return;
338
339         if ((status = usb_submit_urb (hub->urb, GFP_ATOMIC)) != 0
340                         && status != -ENODEV && status != -EPERM)
341                 dev_err (hub->intfdev, "resubmit --> %d\n", status);
342 }
343
344 /* USB 2.0 spec Section 11.24.2.3 */
345 static inline int
346 hub_clear_tt_buffer (struct usb_device *hdev, u16 devinfo, u16 tt)
347 {
348         return usb_control_msg(hdev, usb_rcvctrlpipe(hdev, 0),
349                                HUB_CLEAR_TT_BUFFER, USB_RT_PORT, devinfo,
350                                tt, NULL, 0, 1000);
351 }
352
353 /*
354  * enumeration blocks khubd for a long time. we use keventd instead, since
355  * long blocking there is the exception, not the rule.  accordingly, HCDs
356  * talking to TTs must queue control transfers (not just bulk and iso), so
357  * both can talk to the same hub concurrently.
358  */
359 static void hub_tt_kevent (void *arg)
360 {
361         struct usb_hub          *hub = arg;
362         unsigned long           flags;
363
364         spin_lock_irqsave (&hub->tt.lock, flags);
365         while (!list_empty (&hub->tt.clear_list)) {
366                 struct list_head        *temp;
367                 struct usb_tt_clear     *clear;
368                 struct usb_device       *hdev = hub->hdev;
369                 int                     status;
370
371                 temp = hub->tt.clear_list.next;
372                 clear = list_entry (temp, struct usb_tt_clear, clear_list);
373                 list_del (&clear->clear_list);
374
375                 /* drop lock so HCD can concurrently report other TT errors */
376                 spin_unlock_irqrestore (&hub->tt.lock, flags);
377                 status = hub_clear_tt_buffer (hdev, clear->devinfo, clear->tt);
378                 spin_lock_irqsave (&hub->tt.lock, flags);
379
380                 if (status)
381                         dev_err (&hdev->dev,
382                                 "clear tt %d (%04x) error %d\n",
383                                 clear->tt, clear->devinfo, status);
384                 kfree(clear);
385         }
386         spin_unlock_irqrestore (&hub->tt.lock, flags);
387 }
388
389 /**
390  * usb_hub_tt_clear_buffer - clear control/bulk TT state in high speed hub
391  * @udev: the device whose split transaction failed
392  * @pipe: identifies the endpoint of the failed transaction
393  *
394  * High speed HCDs use this to tell the hub driver that some split control or
395  * bulk transaction failed in a way that requires clearing internal state of
396  * a transaction translator.  This is normally detected (and reported) from
397  * interrupt context.
398  *
399  * It may not be possible for that hub to handle additional full (or low)
400  * speed transactions until that state is fully cleared out.
401  */
402 void usb_hub_tt_clear_buffer (struct usb_device *udev, int pipe)
403 {
404         struct usb_tt           *tt = udev->tt;
405         unsigned long           flags;
406         struct usb_tt_clear     *clear;
407
408         /* we've got to cope with an arbitrary number of pending TT clears,
409          * since each TT has "at least two" buffers that can need it (and
410          * there can be many TTs per hub).  even if they're uncommon.
411          */
412         if ((clear = kmalloc (sizeof *clear, SLAB_ATOMIC)) == NULL) {
413                 dev_err (&udev->dev, "can't save CLEAR_TT_BUFFER state\n");
414                 /* FIXME recover somehow ... RESET_TT? */
415                 return;
416         }
417
418         /* info that CLEAR_TT_BUFFER needs */
419         clear->tt = tt->multi ? udev->ttport : 1;
420         clear->devinfo = usb_pipeendpoint (pipe);
421         clear->devinfo |= udev->devnum << 4;
422         clear->devinfo |= usb_pipecontrol (pipe)
423                         ? (USB_ENDPOINT_XFER_CONTROL << 11)
424                         : (USB_ENDPOINT_XFER_BULK << 11);
425         if (usb_pipein (pipe))
426                 clear->devinfo |= 1 << 15;
427         
428         /* tell keventd to clear state for this TT */
429         spin_lock_irqsave (&tt->lock, flags);
430         list_add_tail (&clear->clear_list, &tt->clear_list);
431         schedule_work (&tt->kevent);
432         spin_unlock_irqrestore (&tt->lock, flags);
433 }
434
435 static void hub_power_on(struct usb_hub *hub)
436 {
437         int port1;
438
439         /* if hub supports power switching, enable power on each port */
440         if ((hub->descriptor->wHubCharacteristics & HUB_CHAR_LPSM) < 2) {
441                 dev_dbg(hub->intfdev, "enabling power on all ports\n");
442                 for (port1 = 1; port1 <= hub->descriptor->bNbrPorts; port1++)
443                         set_port_feature(hub->hdev, port1,
444                                         USB_PORT_FEAT_POWER);
445         }
446
447         /* Wait for power to be enabled */
448         msleep(hub->descriptor->bPwrOn2PwrGood * 2);
449 }
450
451 static void hub_quiesce(struct usb_hub *hub)
452 {
453         /* stop khubd and related activity */
454         hub->quiescing = 1;
455         usb_kill_urb(hub->urb);
456         if (hub->has_indicators)
457                 cancel_delayed_work(&hub->leds);
458         if (hub->has_indicators || hub->tt.hub)
459                 flush_scheduled_work();
460 }
461
462 static void hub_activate(struct usb_hub *hub)
463 {
464         int     status;
465
466         hub->quiescing = 0;
467         hub->activating = 1;
468         status = usb_submit_urb(hub->urb, GFP_NOIO);
469         if (status < 0)
470                 dev_err(hub->intfdev, "activate --> %d\n", status);
471         if (hub->has_indicators && blinkenlights)
472                 schedule_delayed_work(&hub->leds, LED_CYCLE_PERIOD);
473
474         /* scan all ports ASAP */
475         kick_khubd(hub);
476 }
477
478 static int hub_hub_status(struct usb_hub *hub,
479                 u16 *status, u16 *change)
480 {
481         int ret;
482
483         ret = get_hub_status(hub->hdev, &hub->status->hub);
484         if (ret < 0)
485                 dev_err (hub->intfdev,
486                         "%s failed (err = %d)\n", __FUNCTION__, ret);
487         else {
488                 *status = le16_to_cpu(hub->status->hub.wHubStatus);
489                 *change = le16_to_cpu(hub->status->hub.wHubChange); 
490                 ret = 0;
491         }
492         return ret;
493 }
494
495 static int hub_configure(struct usb_hub *hub,
496         struct usb_endpoint_descriptor *endpoint)
497 {
498         struct usb_device *hdev = hub->hdev;
499         struct device *hub_dev = hub->intfdev;
500         u16 hubstatus, hubchange;
501         unsigned int pipe;
502         int maxp, ret;
503         char *message;
504
505         hub->buffer = usb_buffer_alloc(hdev, sizeof(*hub->buffer), GFP_KERNEL,
506                         &hub->buffer_dma);
507         if (!hub->buffer) {
508                 message = "can't allocate hub irq buffer";
509                 ret = -ENOMEM;
510                 goto fail;
511         }
512
513         hub->status = kmalloc(sizeof(*hub->status), GFP_KERNEL);
514         if (!hub->status) {
515                 message = "can't kmalloc hub status buffer";
516                 ret = -ENOMEM;
517                 goto fail;
518         }
519
520         hub->descriptor = kmalloc(sizeof(*hub->descriptor), GFP_KERNEL);
521         if (!hub->descriptor) {
522                 message = "can't kmalloc hub descriptor";
523                 ret = -ENOMEM;
524                 goto fail;
525         }
526
527         /* Request the entire hub descriptor.
528          * hub->descriptor can handle USB_MAXCHILDREN ports,
529          * but the hub can/will return fewer bytes here.
530          */
531         ret = get_hub_descriptor(hdev, hub->descriptor,
532                         sizeof(*hub->descriptor));
533         if (ret < 0) {
534                 message = "can't read hub descriptor";
535                 goto fail;
536         } else if (hub->descriptor->bNbrPorts > USB_MAXCHILDREN) {
537                 message = "hub has too many ports!";
538                 ret = -ENODEV;
539                 goto fail;
540         }
541
542         hdev->maxchild = hub->descriptor->bNbrPorts;
543         dev_info (hub_dev, "%d port%s detected\n", hdev->maxchild,
544                 (hdev->maxchild == 1) ? "" : "s");
545
546         le16_to_cpus(&hub->descriptor->wHubCharacteristics);
547
548         if (hub->descriptor->wHubCharacteristics & HUB_CHAR_COMPOUND) {
549                 int     i;
550                 char    portstr [USB_MAXCHILDREN + 1];
551
552                 for (i = 0; i < hdev->maxchild; i++)
553                         portstr[i] = hub->descriptor->DeviceRemovable
554                                     [((i + 1) / 8)] & (1 << ((i + 1) % 8))
555                                 ? 'F' : 'R';
556                 portstr[hdev->maxchild] = 0;
557                 dev_dbg(hub_dev, "compound device; port removable status: %s\n", portstr);
558         } else
559                 dev_dbg(hub_dev, "standalone hub\n");
560
561         switch (hub->descriptor->wHubCharacteristics & HUB_CHAR_LPSM) {
562                 case 0x00:
563                         dev_dbg(hub_dev, "ganged power switching\n");
564                         break;
565                 case 0x01:
566                         dev_dbg(hub_dev, "individual port power switching\n");
567                         break;
568                 case 0x02:
569                 case 0x03:
570                         dev_dbg(hub_dev, "no power switching (usb 1.0)\n");
571                         break;
572         }
573
574         switch (hub->descriptor->wHubCharacteristics & HUB_CHAR_OCPM) {
575                 case 0x00:
576                         dev_dbg(hub_dev, "global over-current protection\n");
577                         break;
578                 case 0x08:
579                         dev_dbg(hub_dev, "individual port over-current protection\n");
580                         break;
581                 case 0x10:
582                 case 0x18:
583                         dev_dbg(hub_dev, "no over-current protection\n");
584                         break;
585         }
586
587         spin_lock_init (&hub->tt.lock);
588         INIT_LIST_HEAD (&hub->tt.clear_list);
589         INIT_WORK (&hub->tt.kevent, hub_tt_kevent, hub);
590         switch (hdev->descriptor.bDeviceProtocol) {
591                 case 0:
592                         break;
593                 case 1:
594                         dev_dbg(hub_dev, "Single TT\n");
595                         hub->tt.hub = hdev;
596                         break;
597                 case 2:
598                         ret = usb_set_interface(hdev, 0, 1);
599                         if (ret == 0) {
600                                 dev_dbg(hub_dev, "TT per port\n");
601                                 hub->tt.multi = 1;
602                         } else
603                                 dev_err(hub_dev, "Using single TT (err %d)\n",
604                                         ret);
605                         hub->tt.hub = hdev;
606                         break;
607                 default:
608                         dev_dbg(hub_dev, "Unrecognized hub protocol %d\n",
609                                 hdev->descriptor.bDeviceProtocol);
610                         break;
611         }
612
613         switch (hub->descriptor->wHubCharacteristics & HUB_CHAR_TTTT) {
614                 case 0x00:
615                         if (hdev->descriptor.bDeviceProtocol != 0)
616                                 dev_dbg(hub_dev, "TT requires at most 8 FS bit times\n");
617                         break;
618                 case 0x20:
619                         dev_dbg(hub_dev, "TT requires at most 16 FS bit times\n");
620                         break;
621                 case 0x40:
622                         dev_dbg(hub_dev, "TT requires at most 24 FS bit times\n");
623                         break;
624                 case 0x60:
625                         dev_dbg(hub_dev, "TT requires at most 32 FS bit times\n");
626                         break;
627         }
628
629         /* probe() zeroes hub->indicator[] */
630         if (hub->descriptor->wHubCharacteristics & HUB_CHAR_PORTIND) {
631                 hub->has_indicators = 1;
632                 dev_dbg(hub_dev, "Port indicators are supported\n");
633         }
634
635         dev_dbg(hub_dev, "power on to power good time: %dms\n",
636                 hub->descriptor->bPwrOn2PwrGood * 2);
637
638         /* power budgeting mostly matters with bus-powered hubs,
639          * and battery-powered root hubs (may provide just 8 mA).
640          */
641         ret = usb_get_status(hdev, USB_RECIP_DEVICE, 0, &hubstatus);
642         if (ret < 0) {
643                 message = "can't get hub status";
644                 goto fail;
645         }
646         le16_to_cpus(&hubstatus);
647         if (hdev == hdev->bus->root_hub) {
648                 struct usb_hcd *hcd =
649                                 container_of(hdev->bus, struct usb_hcd, self);
650
651                 hub->power_budget = min(500u, hcd->power_budget) / 2;
652         } else if ((hubstatus & (1 << USB_DEVICE_SELF_POWERED)) == 0) {
653                 dev_dbg(hub_dev, "hub controller current requirement: %dmA\n",
654                         hub->descriptor->bHubContrCurrent);
655                 hub->power_budget = (501 - hub->descriptor->bHubContrCurrent)
656                                         / 2;
657         }
658         if (hub->power_budget)
659                 dev_dbg(hub_dev, "%dmA bus power budget for children\n",
660                         hub->power_budget * 2);
661
662
663         ret = hub_hub_status(hub, &hubstatus, &hubchange);
664         if (ret < 0) {
665                 message = "can't get hub status";
666                 goto fail;
667         }
668
669         /* local power status reports aren't always correct */
670         if (hdev->actconfig->desc.bmAttributes & USB_CONFIG_ATT_SELFPOWER)
671                 dev_dbg(hub_dev, "local power source is %s\n",
672                         (hubstatus & HUB_STATUS_LOCAL_POWER)
673                         ? "lost (inactive)" : "good");
674
675         if ((hub->descriptor->wHubCharacteristics & HUB_CHAR_OCPM) == 0)
676                 dev_dbg(hub_dev, "%sover-current condition exists\n",
677                         (hubstatus & HUB_STATUS_OVERCURRENT) ? "" : "no ");
678
679         /* set up the interrupt endpoint */
680         pipe = usb_rcvintpipe(hdev, endpoint->bEndpointAddress);
681         maxp = usb_maxpacket(hdev, pipe, usb_pipeout(pipe));
682
683         if (maxp > sizeof(*hub->buffer))
684                 maxp = sizeof(*hub->buffer);
685
686         hub->urb = usb_alloc_urb(0, GFP_KERNEL);
687         if (!hub->urb) {
688                 message = "couldn't allocate interrupt urb";
689                 ret = -ENOMEM;
690                 goto fail;
691         }
692
693         usb_fill_int_urb(hub->urb, hdev, pipe, *hub->buffer, maxp, hub_irq,
694                 hub, endpoint->bInterval);
695         hub->urb->transfer_dma = hub->buffer_dma;
696         hub->urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
697
698         /* maybe cycle the hub leds */
699         if (hub->has_indicators && blinkenlights)
700                 hub->indicator [0] = INDICATOR_CYCLE;
701
702         hub_power_on(hub);
703         hub_activate(hub);
704         return 0;
705
706 fail:
707         dev_err (hub_dev, "config failed, %s (err %d)\n",
708                         message, ret);
709         /* hub_disconnect() frees urb and descriptor */
710         return ret;
711 }
712
713 static unsigned highspeed_hubs;
714
715 static void hub_disconnect(struct usb_interface *intf)
716 {
717         struct usb_hub *hub = usb_get_intfdata (intf);
718         struct usb_device *hdev;
719
720         if (!hub)
721                 return;
722         hdev = hub->hdev;
723
724         if (hdev->speed == USB_SPEED_HIGH)
725                 highspeed_hubs--;
726
727         usb_set_intfdata (intf, NULL);
728
729         hub_quiesce(hub);
730         usb_free_urb(hub->urb);
731         hub->urb = NULL;
732
733         spin_lock_irq(&hub_event_lock);
734         list_del_init(&hub->event_list);
735         spin_unlock_irq(&hub_event_lock);
736
737         kfree(hub->descriptor);
738         hub->descriptor = NULL;
739
740         kfree(hub->status);
741         hub->status = NULL;
742
743         if (hub->buffer) {
744                 usb_buffer_free(hdev, sizeof(*hub->buffer), hub->buffer,
745                                 hub->buffer_dma);
746                 hub->buffer = NULL;
747         }
748
749         /* Free the memory */
750         kfree(hub);
751 }
752
753 static int hub_probe(struct usb_interface *intf, const struct usb_device_id *id)
754 {
755         struct usb_host_interface *desc;
756         struct usb_endpoint_descriptor *endpoint;
757         struct usb_device *hdev;
758         struct usb_hub *hub;
759
760         desc = intf->cur_altsetting;
761         hdev = interface_to_usbdev(intf);
762
763         /* Some hubs have a subclass of 1, which AFAICT according to the */
764         /*  specs is not defined, but it works */
765         if ((desc->desc.bInterfaceSubClass != 0) &&
766             (desc->desc.bInterfaceSubClass != 1)) {
767 descriptor_error:
768                 dev_err (&intf->dev, "bad descriptor, ignoring hub\n");
769                 return -EIO;
770         }
771
772         /* Multiple endpoints? What kind of mutant ninja-hub is this? */
773         if (desc->desc.bNumEndpoints != 1)
774                 goto descriptor_error;
775
776         endpoint = &desc->endpoint[0].desc;
777
778         /* Output endpoint? Curiouser and curiouser.. */
779         if (!(endpoint->bEndpointAddress & USB_DIR_IN))
780                 goto descriptor_error;
781
782         /* If it's not an interrupt endpoint, we'd better punt! */
783         if ((endpoint->bmAttributes & USB_ENDPOINT_XFERTYPE_MASK)
784                         != USB_ENDPOINT_XFER_INT)
785                 goto descriptor_error;
786
787         /* We found a hub */
788         dev_info (&intf->dev, "USB hub found\n");
789
790         hub = kmalloc(sizeof(*hub), GFP_KERNEL);
791         if (!hub) {
792                 dev_dbg (&intf->dev, "couldn't kmalloc hub struct\n");
793                 return -ENOMEM;
794         }
795
796         memset(hub, 0, sizeof(*hub));
797
798         INIT_LIST_HEAD(&hub->event_list);
799         hub->intfdev = &intf->dev;
800         hub->hdev = hdev;
801         INIT_WORK(&hub->leds, led_work, hub);
802
803         usb_set_intfdata (intf, hub);
804
805         if (hdev->speed == USB_SPEED_HIGH)
806                 highspeed_hubs++;
807
808         if (hub_configure(hub, endpoint) >= 0)
809                 return 0;
810
811         hub_disconnect (intf);
812         return -ENODEV;
813 }
814
815 static int
816 hub_ioctl(struct usb_interface *intf, unsigned int code, void *user_data)
817 {
818         struct usb_device *hdev = interface_to_usbdev (intf);
819
820         /* assert ifno == 0 (part of hub spec) */
821         switch (code) {
822         case USBDEVFS_HUB_PORTINFO: {
823                 struct usbdevfs_hub_portinfo *info = user_data;
824                 int i;
825
826                 spin_lock_irq(&device_state_lock);
827                 if (hdev->devnum <= 0)
828                         info->nports = 0;
829                 else {
830                         info->nports = hdev->maxchild;
831                         for (i = 0; i < info->nports; i++) {
832                                 if (hdev->children[i] == NULL)
833                                         info->port[i] = 0;
834                                 else
835                                         info->port[i] =
836                                                 hdev->children[i]->devnum;
837                         }
838                 }
839                 spin_unlock_irq(&device_state_lock);
840
841                 return info->nports + 1;
842                 }
843
844         default:
845                 return -ENOSYS;
846         }
847 }
848
849 /* caller has locked the hub device */
850 static void hub_pre_reset(struct usb_hub *hub)
851 {
852         struct usb_device *hdev = hub->hdev;
853         int i;
854
855         for (i = 0; i < hdev->maxchild; ++i) {
856                 if (hdev->children[i])
857                         usb_disconnect(&hdev->children[i]);
858         }
859         hub_quiesce(hub);
860 }
861
862 /* caller has locked the hub device */
863 static void hub_post_reset(struct usb_hub *hub)
864 {
865         hub_activate(hub);
866         hub_power_on(hub);
867 }
868
869
870 /* grab device/port lock, returning index of that port (zero based).
871  * protects the upstream link used by this device from concurrent
872  * tree operations like suspend, resume, reset, and disconnect, which
873  * apply to everything downstream of a given port.
874  */
875 static int locktree(struct usb_device *udev)
876 {
877         int                     t;
878         struct usb_device       *hdev;
879
880         if (!udev)
881                 return -ENODEV;
882
883         /* root hub is always the first lock in the series */
884         hdev = udev->parent;
885         if (!hdev) {
886                 usb_lock_device(udev);
887                 return 0;
888         }
889
890         /* on the path from root to us, lock everything from
891          * top down, dropping parent locks when not needed
892          */
893         t = locktree(hdev);
894         if (t < 0)
895                 return t;
896         for (t = 0; t < hdev->maxchild; t++) {
897                 if (hdev->children[t] == udev) {
898                         /* everything is fail-fast once disconnect
899                          * processing starts
900                          */
901                         if (udev->state == USB_STATE_NOTATTACHED)
902                                 break;
903
904                         /* when everyone grabs locks top->bottom,
905                          * non-overlapping work may be concurrent
906                          */
907                         down(&udev->serialize);
908                         up(&hdev->serialize);
909                         return t + 1;
910                 }
911         }
912         usb_unlock_device(hdev);
913         return -ENODEV;
914 }
915
916 static void recursively_mark_NOTATTACHED(struct usb_device *udev)
917 {
918         int i;
919
920         for (i = 0; i < udev->maxchild; ++i) {
921                 if (udev->children[i])
922                         recursively_mark_NOTATTACHED(udev->children[i]);
923         }
924         udev->state = USB_STATE_NOTATTACHED;
925 }
926
927 /**
928  * usb_set_device_state - change a device's current state (usbcore, hcds)
929  * @udev: pointer to device whose state should be changed
930  * @new_state: new state value to be stored
931  *
932  * udev->state is _not_ fully protected by the device lock.  Although
933  * most transitions are made only while holding the lock, the state can
934  * can change to USB_STATE_NOTATTACHED at almost any time.  This
935  * is so that devices can be marked as disconnected as soon as possible,
936  * without having to wait for any semaphores to be released.  As a result,
937  * all changes to any device's state must be protected by the
938  * device_state_lock spinlock.
939  *
940  * Once a device has been added to the device tree, all changes to its state
941  * should be made using this routine.  The state should _not_ be set directly.
942  *
943  * If udev->state is already USB_STATE_NOTATTACHED then no change is made.
944  * Otherwise udev->state is set to new_state, and if new_state is
945  * USB_STATE_NOTATTACHED then all of udev's descendants' states are also set
946  * to USB_STATE_NOTATTACHED.
947  */
948 void usb_set_device_state(struct usb_device *udev,
949                 enum usb_device_state new_state)
950 {
951         unsigned long flags;
952
953         spin_lock_irqsave(&device_state_lock, flags);
954         if (udev->state == USB_STATE_NOTATTACHED)
955                 ;       /* do nothing */
956         else if (new_state != USB_STATE_NOTATTACHED)
957                 udev->state = new_state;
958         else
959                 recursively_mark_NOTATTACHED(udev);
960         spin_unlock_irqrestore(&device_state_lock, flags);
961 }
962 EXPORT_SYMBOL(usb_set_device_state);
963
964
965 static void choose_address(struct usb_device *udev)
966 {
967         int             devnum;
968         struct usb_bus  *bus = udev->bus;
969
970         /* If khubd ever becomes multithreaded, this will need a lock */
971
972         /* Try to allocate the next devnum beginning at bus->devnum_next. */
973         devnum = find_next_zero_bit(bus->devmap.devicemap, 128,
974                         bus->devnum_next);
975         if (devnum >= 128)
976                 devnum = find_next_zero_bit(bus->devmap.devicemap, 128, 1);
977
978         bus->devnum_next = ( devnum >= 127 ? 1 : devnum + 1);
979
980         if (devnum < 128) {
981                 set_bit(devnum, bus->devmap.devicemap);
982                 udev->devnum = devnum;
983         }
984 }
985
986 static void release_address(struct usb_device *udev)
987 {
988         if (udev->devnum > 0) {
989                 clear_bit(udev->devnum, udev->bus->devmap.devicemap);
990                 udev->devnum = -1;
991         }
992 }
993
994 /**
995  * usb_disconnect - disconnect a device (usbcore-internal)
996  * @pdev: pointer to device being disconnected
997  * Context: !in_interrupt ()
998  *
999  * Something got disconnected. Get rid of it and all of its children.
1000  *
1001  * If *pdev is a normal device then the parent hub must already be locked.
1002  * If *pdev is a root hub then this routine will acquire the
1003  * usb_bus_list_lock on behalf of the caller.
1004  *
1005  * Only hub drivers (including virtual root hub drivers for host
1006  * controllers) should ever call this.
1007  *
1008  * This call is synchronous, and may not be used in an interrupt context.
1009  */
1010 void usb_disconnect(struct usb_device **pdev)
1011 {
1012         struct usb_device       *udev = *pdev;
1013         int                     i;
1014
1015         if (!udev) {
1016                 pr_debug ("%s nodev\n", __FUNCTION__);
1017                 return;
1018         }
1019
1020         /* mark the device as inactive, so any further urb submissions for
1021          * this device (and any of its children) will fail immediately.
1022          * this quiesces everyting except pending urbs.
1023          */
1024         usb_set_device_state(udev, USB_STATE_NOTATTACHED);
1025
1026         /* lock the bus list on behalf of HCDs unregistering their root hubs */
1027         if (!udev->parent) {
1028                 down(&usb_bus_list_lock);
1029                 usb_lock_device(udev);
1030         } else
1031                 down(&udev->serialize);
1032
1033         dev_info (&udev->dev, "USB disconnect, address %d\n", udev->devnum);
1034
1035         /* Free up all the children before we remove this device */
1036         for (i = 0; i < USB_MAXCHILDREN; i++) {
1037                 if (udev->children[i])
1038                         usb_disconnect(&udev->children[i]);
1039         }
1040
1041         /* deallocate hcd/hardware state ... nuking all pending urbs and
1042          * cleaning up all state associated with the current configuration
1043          * so that the hardware is now fully quiesced.
1044          */
1045         usb_disable_device(udev, 0);
1046
1047         /* Free the device number, remove the /proc/bus/usb entry and
1048          * the sysfs attributes, and delete the parent's children[]
1049          * (or root_hub) pointer.
1050          */
1051         dev_dbg (&udev->dev, "unregistering device\n");
1052         release_address(udev);
1053         usbfs_remove_device(udev);
1054         usb_remove_sysfs_dev_files(udev);
1055
1056         /* Avoid races with recursively_mark_NOTATTACHED() */
1057         spin_lock_irq(&device_state_lock);
1058         *pdev = NULL;
1059         spin_unlock_irq(&device_state_lock);
1060
1061         if (!udev->parent) {
1062                 usb_unlock_device(udev);
1063                 up(&usb_bus_list_lock);
1064         } else
1065                 up(&udev->serialize);
1066
1067         device_unregister(&udev->dev);
1068 }
1069
1070 static int choose_configuration(struct usb_device *udev)
1071 {
1072         int c, i;
1073
1074         /* NOTE: this should interact with hub power budgeting */
1075
1076         c = udev->config[0].desc.bConfigurationValue;
1077         if (udev->descriptor.bNumConfigurations != 1) {
1078                 for (i = 0; i < udev->descriptor.bNumConfigurations; i++) {
1079                         struct usb_interface_descriptor *desc;
1080
1081                         /* heuristic:  Linux is more likely to have class
1082                          * drivers, so avoid vendor-specific interfaces.
1083                          */
1084                         desc = &udev->config[i].intf_cache[0]
1085                                         ->altsetting->desc;
1086                         if (desc->bInterfaceClass == USB_CLASS_VENDOR_SPEC)
1087                                 continue;
1088                         /* COMM/2/all is CDC ACM, except 0xff is MSFT RNDIS.
1089                          * MSFT needs this to be the first config; never use
1090                          * it as the default unless Linux has host-side RNDIS.
1091                          * A second config would ideally be CDC-Ethernet, but
1092                          * may instead be the "vendor specific" CDC subset
1093                          * long used by ARM Linux for sa1100 or pxa255.
1094                          */
1095                         if (desc->bInterfaceClass == USB_CLASS_COMM
1096                                         && desc->bInterfaceSubClass == 2
1097                                         && desc->bInterfaceProtocol == 0xff) {
1098                                 c = udev->config[1].desc.bConfigurationValue;
1099                                 continue;
1100                         }
1101                         c = udev->config[i].desc.bConfigurationValue;
1102                         break;
1103                 }
1104                 dev_info(&udev->dev,
1105                         "configuration #%d chosen from %d choices\n",
1106                         c, udev->descriptor.bNumConfigurations);
1107         }
1108         return c;
1109 }
1110
1111 #ifdef DEBUG
1112 static void show_string(struct usb_device *udev, char *id, char *string)
1113 {
1114         if (!string)
1115                 return;
1116         dev_printk(KERN_INFO, &udev->dev, "%s: %s\n", id, string);
1117 }
1118
1119 #else
1120 static inline void show_string(struct usb_device *udev, char *id, char *string)
1121 {}
1122 #endif
1123
1124 static void get_string(struct usb_device *udev, char **string, int index)
1125 {
1126         char *buf;
1127
1128         if (!index)
1129                 return;
1130         buf = kmalloc(256, GFP_KERNEL);
1131         if (!buf)
1132                 return;
1133         if (usb_string(udev, index, buf, 256) > 0)
1134                 *string = buf;
1135         else
1136                 kfree(buf);
1137 }
1138
1139
1140 #ifdef  CONFIG_USB_OTG
1141 #include "otg_whitelist.h"
1142 #endif
1143
1144 /**
1145  * usb_new_device - perform initial device setup (usbcore-internal)
1146  * @udev: newly addressed device (in ADDRESS state)
1147  *
1148  * This is called with devices which have been enumerated, but not yet
1149  * configured.  The device descriptor is available, but not descriptors
1150  * for any device configuration.  The caller must have locked udev and
1151  * either the parent hub (if udev is a normal device) or else the
1152  * usb_bus_list_lock (if udev is a root hub).  The parent's pointer to
1153  * udev has already been installed, but udev is not yet visible through
1154  * sysfs or other filesystem code.
1155  *
1156  * Returns 0 for success (device is configured and listed, with its
1157  * interfaces, in sysfs); else a negative errno value.
1158  *
1159  * This call is synchronous, and may not be used in an interrupt context.
1160  *
1161  * Only the hub driver should ever call this; root hub registration
1162  * uses it indirectly.
1163  */
1164 int usb_new_device(struct usb_device *udev)
1165 {
1166         int err;
1167         int c;
1168
1169         err = usb_get_configuration(udev);
1170         if (err < 0) {
1171                 dev_err(&udev->dev, "can't read configurations, error %d\n",
1172                         err);
1173                 goto fail;
1174         }
1175
1176         /* read the standard strings and cache them if present */
1177         get_string(udev, &udev->product, udev->descriptor.iProduct);
1178         get_string(udev, &udev->manufacturer, udev->descriptor.iManufacturer);
1179         get_string(udev, &udev->serial, udev->descriptor.iSerialNumber);
1180
1181         /* Tell the world! */
1182         dev_dbg(&udev->dev, "new device strings: Mfr=%d, Product=%d, "
1183                         "SerialNumber=%d\n",
1184                         udev->descriptor.iManufacturer,
1185                         udev->descriptor.iProduct,
1186                         udev->descriptor.iSerialNumber);
1187         show_string(udev, "Product", udev->product);
1188         show_string(udev, "Manufacturer", udev->manufacturer);
1189         show_string(udev, "SerialNumber", udev->serial);
1190
1191 #ifdef  CONFIG_USB_OTG
1192         /*
1193          * OTG-aware devices on OTG-capable root hubs may be able to use SRP,
1194          * to wake us after we've powered off VBUS; and HNP, switching roles
1195          * "host" to "peripheral".  The OTG descriptor helps figure this out.
1196          */
1197         if (!udev->bus->is_b_host
1198                         && udev->config
1199                         && udev->parent == udev->bus->root_hub) {
1200                 struct usb_otg_descriptor       *desc = 0;
1201                 struct usb_bus                  *bus = udev->bus;
1202
1203                 /* descriptor may appear anywhere in config */
1204                 if (__usb_get_extra_descriptor (udev->rawdescriptors[0],
1205                                         le16_to_cpu(udev->config[0].desc.wTotalLength),
1206                                         USB_DT_OTG, (void **) &desc) == 0) {
1207                         if (desc->bmAttributes & USB_OTG_HNP) {
1208                                 unsigned                port1;
1209                                 struct usb_device       *root = udev->parent;
1210                                 
1211                                 for (port1 = 1; port1 <= root->maxchild;
1212                                                 port1++) {
1213                                         if (root->children[port1-1] == udev)
1214                                                 break;
1215                                 }
1216
1217                                 dev_info(&udev->dev,
1218                                         "Dual-Role OTG device on %sHNP port\n",
1219                                         (port1 == bus->otg_port)
1220                                                 ? "" : "non-");
1221
1222                                 /* enable HNP before suspend, it's simpler */
1223                                 if (port1 == bus->otg_port)
1224                                         bus->b_hnp_enable = 1;
1225                                 err = usb_control_msg(udev,
1226                                         usb_sndctrlpipe(udev, 0),
1227                                         USB_REQ_SET_FEATURE, 0,
1228                                         bus->b_hnp_enable
1229                                                 ? USB_DEVICE_B_HNP_ENABLE
1230                                                 : USB_DEVICE_A_ALT_HNP_SUPPORT,
1231                                         0, NULL, 0, USB_CTRL_SET_TIMEOUT);
1232                                 if (err < 0) {
1233                                         /* OTG MESSAGE: report errors here,
1234                                          * customize to match your product.
1235                                          */
1236                                         dev_info(&udev->dev,
1237                                                 "can't set HNP mode; %d\n",
1238                                                 err);
1239                                         bus->b_hnp_enable = 0;
1240                                 }
1241                         }
1242                 }
1243         }
1244
1245         if (!is_targeted(udev)) {
1246
1247                 /* Maybe it can talk to us, though we can't talk to it.
1248                  * (Includes HNP test device.)
1249                  */
1250                 if (udev->bus->b_hnp_enable || udev->bus->is_b_host) {
1251                         static int __usb_suspend_device (struct usb_device *,
1252                                                 int port1, pm_message_t state);
1253                         err = __usb_suspend_device(udev,
1254                                         udev->bus->otg_port,
1255                                         PMSG_SUSPEND);
1256                         if (err < 0)
1257                                 dev_dbg(&udev->dev, "HNP fail, %d\n", err);
1258                 }
1259                 err = -ENODEV;
1260                 goto fail;
1261         }
1262 #endif
1263
1264         /* put device-specific files into sysfs */
1265         err = device_add (&udev->dev);
1266         if (err) {
1267                 dev_err(&udev->dev, "can't device_add, error %d\n", err);
1268                 goto fail;
1269         }
1270         usb_create_sysfs_dev_files (udev);
1271
1272         /* choose and set the configuration. that registers the interfaces
1273          * with the driver core, and lets usb device drivers bind to them.
1274          */
1275         c = choose_configuration(udev);
1276         if (c < 0)
1277                 dev_warn(&udev->dev,
1278                                 "can't choose an initial configuration\n");
1279         else {
1280                 err = usb_set_configuration(udev, c);
1281                 if (err) {
1282                         dev_err(&udev->dev, "can't set config #%d, error %d\n",
1283                                         c, err);
1284                         usb_remove_sysfs_dev_files(udev);
1285                         device_del(&udev->dev);
1286                         goto fail;
1287                 }
1288         }
1289
1290         /* USB device state == configured ... usable */
1291
1292         /* add a /proc/bus/usb entry */
1293         usbfs_add_device(udev);
1294         return 0;
1295
1296 fail:
1297         usb_set_device_state(udev, USB_STATE_NOTATTACHED);
1298         return err;
1299 }
1300
1301
1302 static int hub_port_status(struct usb_hub *hub, int port1,
1303                                u16 *status, u16 *change)
1304 {
1305         int ret;
1306
1307         ret = get_port_status(hub->hdev, port1, &hub->status->port);
1308         if (ret < 0)
1309                 dev_err (hub->intfdev,
1310                         "%s failed (err = %d)\n", __FUNCTION__, ret);
1311         else {
1312                 *status = le16_to_cpu(hub->status->port.wPortStatus);
1313                 *change = le16_to_cpu(hub->status->port.wPortChange); 
1314                 ret = 0;
1315         }
1316         return ret;
1317 }
1318
1319 #define PORT_RESET_TRIES        5
1320 #define SET_ADDRESS_TRIES       2
1321 #define GET_DESCRIPTOR_TRIES    2
1322 #define SET_CONFIG_TRIES        (2 * (use_both_schemes + 1))
1323 #define USE_NEW_SCHEME(i)       ((i) / 2 == old_scheme_first)
1324
1325 #define HUB_ROOT_RESET_TIME     50      /* times are in msec */
1326 #define HUB_SHORT_RESET_TIME    10
1327 #define HUB_LONG_RESET_TIME     200
1328 #define HUB_RESET_TIMEOUT       500
1329
1330 static int hub_port_wait_reset(struct usb_hub *hub, int port1,
1331                                 struct usb_device *udev, unsigned int delay)
1332 {
1333         int delay_time, ret;
1334         u16 portstatus;
1335         u16 portchange;
1336
1337         for (delay_time = 0;
1338                         delay_time < HUB_RESET_TIMEOUT;
1339                         delay_time += delay) {
1340                 /* wait to give the device a chance to reset */
1341                 msleep(delay);
1342
1343                 /* read and decode port status */
1344                 ret = hub_port_status(hub, port1, &portstatus, &portchange);
1345                 if (ret < 0)
1346                         return ret;
1347
1348                 /* Device went away? */
1349                 if (!(portstatus & USB_PORT_STAT_CONNECTION))
1350                         return -ENOTCONN;
1351
1352                 /* bomb out completely if something weird happened */
1353                 if ((portchange & USB_PORT_STAT_C_CONNECTION))
1354                         return -EINVAL;
1355
1356                 /* if we`ve finished resetting, then break out of the loop */
1357                 if (!(portstatus & USB_PORT_STAT_RESET) &&
1358                     (portstatus & USB_PORT_STAT_ENABLE)) {
1359                         if (portstatus & USB_PORT_STAT_HIGH_SPEED)
1360                                 udev->speed = USB_SPEED_HIGH;
1361                         else if (portstatus & USB_PORT_STAT_LOW_SPEED)
1362                                 udev->speed = USB_SPEED_LOW;
1363                         else
1364                                 udev->speed = USB_SPEED_FULL;
1365                         return 0;
1366                 }
1367
1368                 /* switch to the long delay after two short delay failures */
1369                 if (delay_time >= 2 * HUB_SHORT_RESET_TIME)
1370                         delay = HUB_LONG_RESET_TIME;
1371
1372                 dev_dbg (hub->intfdev,
1373                         "port %d not reset yet, waiting %dms\n",
1374                         port1, delay);
1375         }
1376
1377         return -EBUSY;
1378 }
1379
1380 static int hub_port_reset(struct usb_hub *hub, int port1,
1381                                 struct usb_device *udev, unsigned int delay)
1382 {
1383         int i, status;
1384
1385         /* Reset the port */
1386         for (i = 0; i < PORT_RESET_TRIES; i++) {
1387                 status = set_port_feature(hub->hdev,
1388                                 port1, USB_PORT_FEAT_RESET);
1389                 if (status)
1390                         dev_err(hub->intfdev,
1391                                         "cannot reset port %d (err = %d)\n",
1392                                         port1, status);
1393                 else {
1394                         status = hub_port_wait_reset(hub, port1, udev, delay);
1395                         if (status)
1396                                 dev_dbg(hub->intfdev,
1397                                                 "port_wait_reset: err = %d\n",
1398                                                 status);
1399                 }
1400
1401                 /* return on disconnect or reset */
1402                 switch (status) {
1403                 case 0:
1404                         /* TRSTRCY = 10 ms */
1405                         msleep(10);
1406                         /* FALL THROUGH */
1407                 case -ENOTCONN:
1408                 case -ENODEV:
1409                         clear_port_feature(hub->hdev,
1410                                 port1, USB_PORT_FEAT_C_RESET);
1411                         /* FIXME need disconnect() for NOTATTACHED device */
1412                         usb_set_device_state(udev, status
1413                                         ? USB_STATE_NOTATTACHED
1414                                         : USB_STATE_DEFAULT);
1415                         return status;
1416                 }
1417
1418                 dev_dbg (hub->intfdev,
1419                         "port %d not enabled, trying reset again...\n",
1420                         port1);
1421                 delay = HUB_LONG_RESET_TIME;
1422         }
1423
1424         dev_err (hub->intfdev,
1425                 "Cannot enable port %i.  Maybe the USB cable is bad?\n",
1426                 port1);
1427
1428         return status;
1429 }
1430
1431 static int hub_port_disable(struct usb_hub *hub, int port1, int set_state)
1432 {
1433         struct usb_device *hdev = hub->hdev;
1434         int ret;
1435
1436         if (hdev->children[port1-1] && set_state) {
1437                 usb_set_device_state(hdev->children[port1-1],
1438                                 USB_STATE_NOTATTACHED);
1439         }
1440         ret = clear_port_feature(hdev, port1, USB_PORT_FEAT_ENABLE);
1441         if (ret)
1442                 dev_err(hub->intfdev, "cannot disable port %d (err = %d)\n",
1443                         port1, ret);
1444
1445         return ret;
1446 }
1447
1448 /*
1449  * Disable a port and mark a logical connnect-change event, so that some
1450  * time later khubd will disconnect() any existing usb_device on the port
1451  * and will re-enumerate if there actually is a device attached.
1452  */
1453 static void hub_port_logical_disconnect(struct usb_hub *hub, int port1)
1454 {
1455         dev_dbg(hub->intfdev, "logical disconnect on port %d\n", port1);
1456         hub_port_disable(hub, port1, 1);
1457
1458         /* FIXME let caller ask to power down the port:
1459          *  - some devices won't enumerate without a VBUS power cycle
1460          *  - SRP saves power that way
1461          *  - usb_suspend_device(dev, PMSG_SUSPEND)
1462          * That's easy if this hub can switch power per-port, and
1463          * khubd reactivates the port later (timer, SRP, etc).
1464          * Powerdown must be optional, because of reset/DFU.
1465          */
1466
1467         set_bit(port1, hub->change_bits);
1468         kick_khubd(hub);
1469 }
1470
1471
1472 #ifdef  CONFIG_USB_SUSPEND
1473
1474 /*
1475  * Selective port suspend reduces power; most suspended devices draw
1476  * less than 500 uA.  It's also used in OTG, along with remote wakeup.
1477  * All devices below the suspended port are also suspended.
1478  *
1479  * Devices leave suspend state when the host wakes them up.  Some devices
1480  * also support "remote wakeup", where the device can activate the USB
1481  * tree above them to deliver data, such as a keypress or packet.  In
1482  * some cases, this wakes the USB host.
1483  */
1484 static int hub_port_suspend(struct usb_hub *hub, int port1,
1485                 struct usb_device *udev)
1486 {
1487         int     status;
1488
1489         // dev_dbg(hub->intfdev, "suspend port %d\n", port1);
1490
1491         /* enable remote wakeup when appropriate; this lets the device
1492          * wake up the upstream hub (including maybe the root hub).
1493          *
1494          * NOTE:  OTG devices may issue remote wakeup (or SRP) even when
1495          * we don't explicitly enable it here.
1496          */
1497         if (udev->actconfig
1498                         // && FIXME (remote wakeup enabled on this bus)
1499                         // ... currently assuming it's always appropriate
1500                         && (udev->actconfig->desc.bmAttributes
1501                                 & USB_CONFIG_ATT_WAKEUP) != 0) {
1502                 status = usb_control_msg(udev, usb_sndctrlpipe(udev, 0),
1503                                 USB_REQ_SET_FEATURE, USB_RECIP_DEVICE,
1504                                 USB_DEVICE_REMOTE_WAKEUP, 0,
1505                                 NULL, 0,
1506                                 USB_CTRL_SET_TIMEOUT);
1507                 if (status)
1508                         dev_dbg(&udev->dev,
1509                                 "won't remote wakeup, status %d\n",
1510                                 status);
1511         }
1512
1513         /* see 7.1.7.6 */
1514         status = set_port_feature(hub->hdev, port1, USB_PORT_FEAT_SUSPEND);
1515         if (status) {
1516                 dev_dbg(hub->intfdev,
1517                         "can't suspend port %d, status %d\n",
1518                         port1, status);
1519                 /* paranoia:  "should not happen" */
1520                 (void) usb_control_msg(udev, usb_sndctrlpipe(udev, 0),
1521                                 USB_REQ_CLEAR_FEATURE, USB_RECIP_DEVICE,
1522                                 USB_DEVICE_REMOTE_WAKEUP, 0,
1523                                 NULL, 0,
1524                                 USB_CTRL_SET_TIMEOUT);
1525         } else {
1526                 /* device has up to 10 msec to fully suspend */
1527                 dev_dbg(&udev->dev, "usb suspend\n");
1528                 usb_set_device_state(udev, USB_STATE_SUSPENDED);
1529                 msleep(10);
1530         }
1531         return status;
1532 }
1533
1534 /*
1535  * Devices on USB hub ports have only one "suspend" state, corresponding
1536  * to ACPI D2, "may cause the device to lose some context".
1537  * State transitions include:
1538  *
1539  *   - suspend, resume ... when the VBUS power link stays live
1540  *   - suspend, disconnect ... VBUS lost
1541  *
1542  * Once VBUS drop breaks the circuit, the port it's using has to go through
1543  * normal re-enumeration procedures, starting with enabling VBUS power.
1544  * Other than re-initializing the hub (plug/unplug, except for root hubs),
1545  * Linux (2.6) currently has NO mechanisms to initiate that:  no khubd
1546  * timer, no SRP, no requests through sysfs.
1547  */
1548 static int __usb_suspend_device (struct usb_device *udev, int port1,
1549                                  pm_message_t state)
1550 {
1551         int     status;
1552
1553         /* caller owns the udev device lock */
1554         if (port1 < 0)
1555                 return port1;
1556
1557         if (udev->state == USB_STATE_SUSPENDED
1558                         || udev->state == USB_STATE_NOTATTACHED) {
1559                 return 0;
1560         }
1561
1562         /* suspend interface drivers; if this is a hub, it
1563          * suspends the child devices
1564          */
1565         if (udev->actconfig) {
1566                 int     i;
1567
1568                 for (i = 0; i < udev->actconfig->desc.bNumInterfaces; i++) {
1569                         struct usb_interface    *intf;
1570                         struct usb_driver       *driver;
1571
1572                         intf = udev->actconfig->interface[i];
1573                         if (state <= intf->dev.power.power_state)
1574                                 continue;
1575                         if (!intf->dev.driver)
1576                                 continue;
1577                         driver = to_usb_driver(intf->dev.driver);
1578
1579                         if (driver->suspend) {
1580                                 status = driver->suspend(intf, state);
1581                                 if (intf->dev.power.power_state != state
1582                                                 || status)
1583                                         dev_err(&intf->dev,
1584                                                 "suspend %d fail, code %d\n",
1585                                                 state, status);
1586                         }
1587
1588                         /* only drivers with suspend() can ever resume();
1589                          * and after power loss, even they won't.
1590                          * bus_rescan_devices() can rebind drivers later.
1591                          *
1592                          * FIXME the PM core self-deadlocks when unbinding
1593                          * drivers during suspend/resume ... everything grabs
1594                          * dpm_sem (not a spinlock, ugh).  we want to unbind,
1595                          * since we know every driver's probe/disconnect works
1596                          * even for drivers that can't suspend.
1597                          */
1598                         if (!driver->suspend || state > PM_SUSPEND_MEM) {
1599 #if 1
1600                                 dev_warn(&intf->dev, "resume is unsafe!\n");
1601 #else
1602                                 down_write(&usb_bus_type.rwsem);
1603                                 device_release_driver(&intf->dev);
1604                                 up_write(&usb_bus_type.rwsem);
1605 #endif
1606                         }
1607                 }
1608         }
1609
1610         /*
1611          * FIXME this needs port power off call paths too, to help force
1612          * USB into the "generic" PM model.  At least for devices on
1613          * ports that aren't using ganged switching (usually root hubs).
1614          *
1615          * NOTE: SRP-capable links should adopt more aggressive poweroff
1616          * policies (when HNP doesn't apply) once we have mechanisms to
1617          * turn power back on!  (Likely not before 2.7...)
1618          */
1619         if (state > PM_SUSPEND_MEM) {
1620                 dev_warn(&udev->dev, "no poweroff yet, suspending instead\n");
1621         }
1622
1623         /* "global suspend" of the HC-to-USB interface (root hub), or
1624          * "selective suspend" of just one hub-device link.
1625          */
1626         if (!udev->parent) {
1627                 struct usb_bus  *bus = udev->bus;
1628                 if (bus && bus->op->hub_suspend) {
1629                         status = bus->op->hub_suspend (bus);
1630                         if (status == 0) {
1631                                 dev_dbg(&udev->dev, "usb suspend\n");
1632                                 usb_set_device_state(udev,
1633                                                 USB_STATE_SUSPENDED);
1634                         }
1635                 } else
1636                         status = -EOPNOTSUPP;
1637         } else
1638                 status = hub_port_suspend(hdev_to_hub(udev->parent), port1,
1639                                 udev);
1640
1641         if (status == 0)
1642                 udev->dev.power.power_state = state;
1643         return status;
1644 }
1645
1646 /**
1647  * usb_suspend_device - suspend a usb device
1648  * @udev: device that's no longer in active use
1649  * @state: PMSG_SUSPEND to suspend
1650  * Context: must be able to sleep; device not locked
1651  *
1652  * Suspends a USB device that isn't in active use, conserving power.
1653  * Devices may wake out of a suspend, if anything important happens,
1654  * using the remote wakeup mechanism.  They may also be taken out of
1655  * suspend by the host, using usb_resume_device().  It's also routine
1656  * to disconnect devices while they are suspended.
1657  *
1658  * Suspending OTG devices may trigger HNP, if that's been enabled
1659  * between a pair of dual-role devices.  That will change roles, such
1660  * as from A-Host to A-Peripheral or from B-Host back to B-Peripheral.
1661  *
1662  * Returns 0 on success, else negative errno.
1663  */
1664 int usb_suspend_device(struct usb_device *udev, pm_message_t state)
1665 {
1666         int     port1, status;
1667
1668         port1 = locktree(udev);
1669         if (port1 < 0)
1670                 return port1;
1671
1672         status = __usb_suspend_device(udev, port1, state);
1673         usb_unlock_device(udev);
1674         return status;
1675 }
1676
1677 /*
1678  * hardware resume signaling is finished, either because of selective
1679  * resume (by host) or remote wakeup (by device) ... now see what changed
1680  * in the tree that's rooted at this device.
1681  */
1682 static int finish_port_resume(struct usb_device *udev)
1683 {
1684         int     status;
1685         u16     devstatus;
1686
1687         /* caller owns the udev device lock */
1688         dev_dbg(&udev->dev, "usb resume\n");
1689
1690         /* usb ch9 identifies four variants of SUSPENDED, based on what
1691          * state the device resumes to.  Linux currently won't see the
1692          * first two on the host side; they'd be inside hub_port_init()
1693          * during many timeouts, but khubd can't suspend until later.
1694          */
1695         usb_set_device_state(udev, udev->actconfig
1696                         ? USB_STATE_CONFIGURED
1697                         : USB_STATE_ADDRESS);
1698         udev->dev.power.power_state = PMSG_ON;
1699
1700         /* 10.5.4.5 says be sure devices in the tree are still there.
1701          * For now let's assume the device didn't go crazy on resume,
1702          * and device drivers will know about any resume quirks.
1703          */
1704         status = usb_get_status(udev, USB_RECIP_DEVICE, 0, &devstatus);
1705         if (status < 0)
1706                 dev_dbg(&udev->dev,
1707                         "gone after usb resume? status %d\n",
1708                         status);
1709         else if (udev->actconfig) {
1710                 unsigned        i;
1711
1712                 le16_to_cpus(&devstatus);
1713                 if (devstatus & (1 << USB_DEVICE_REMOTE_WAKEUP)) {
1714                         status = usb_control_msg(udev,
1715                                         usb_sndctrlpipe(udev, 0),
1716                                         USB_REQ_CLEAR_FEATURE,
1717                                                 USB_RECIP_DEVICE,
1718                                         USB_DEVICE_REMOTE_WAKEUP, 0,
1719                                         NULL, 0,
1720                                         USB_CTRL_SET_TIMEOUT);
1721                         if (status) {
1722                                 dev_dbg(&udev->dev, "disable remote "
1723                                         "wakeup, status %d\n", status);
1724                                 status = 0;
1725                         }
1726                 }
1727
1728                 /* resume interface drivers; if this is a hub, it
1729                  * resumes the child devices
1730                  */
1731                 for (i = 0; i < udev->actconfig->desc.bNumInterfaces; i++) {
1732                         struct usb_interface    *intf;
1733                         struct usb_driver       *driver;
1734
1735                         intf = udev->actconfig->interface[i];
1736                         if (intf->dev.power.power_state == PMSG_ON)
1737                                 continue;
1738                         if (!intf->dev.driver) {
1739                                 /* FIXME maybe force to alt 0 */
1740                                 continue;
1741                         }
1742                         driver = to_usb_driver(intf->dev.driver);
1743
1744                         /* bus_rescan_devices() may rebind drivers */
1745                         if (!driver->resume)
1746                                 continue;
1747
1748                         /* can we do better than just logging errors? */
1749                         status = driver->resume(intf);
1750                         if (intf->dev.power.power_state != PMSG_ON
1751                                         || status)
1752                                 dev_dbg(&intf->dev,
1753                                         "resume fail, state %d code %d\n",
1754                                         intf->dev.power.power_state, status);
1755                 }
1756                 status = 0;
1757
1758         } else if (udev->devnum <= 0) {
1759                 dev_dbg(&udev->dev, "bogus resume!\n");
1760                 status = -EINVAL;
1761         }
1762         return status;
1763 }
1764
1765 static int
1766 hub_port_resume(struct usb_hub *hub, int port1, struct usb_device *udev)
1767 {
1768         int     status;
1769
1770         // dev_dbg(hub->intfdev, "resume port %d\n", port1);
1771
1772         /* see 7.1.7.7; affects power usage, but not budgeting */
1773         status = clear_port_feature(hub->hdev,
1774                         port1, USB_PORT_FEAT_SUSPEND);
1775         if (status) {
1776                 dev_dbg(hub->intfdev,
1777                         "can't resume port %d, status %d\n",
1778                         port1, status);
1779         } else {
1780                 u16             devstatus;
1781                 u16             portchange;
1782
1783                 /* drive resume for at least 20 msec */
1784                 if (udev)
1785                         dev_dbg(&udev->dev, "RESUME\n");
1786                 msleep(25);
1787
1788 #define LIVE_FLAGS      ( USB_PORT_STAT_POWER \
1789                         | USB_PORT_STAT_ENABLE \
1790                         | USB_PORT_STAT_CONNECTION)
1791
1792                 /* Virtual root hubs can trigger on GET_PORT_STATUS to
1793                  * stop resume signaling.  Then finish the resume
1794                  * sequence.
1795                  */
1796                 devstatus = portchange = 0;
1797                 status = hub_port_status(hub, port1,
1798                                 &devstatus, &portchange);
1799                 if (status < 0
1800                                 || (devstatus & LIVE_FLAGS) != LIVE_FLAGS
1801                                 || (devstatus & USB_PORT_STAT_SUSPEND) != 0
1802                                 ) {
1803                         dev_dbg(hub->intfdev,
1804                                 "port %d status %04x.%04x after resume, %d\n",
1805                                 port1, portchange, devstatus, status);
1806                 } else {
1807                         /* TRSMRCY = 10 msec */
1808                         msleep(10);
1809                         if (udev)
1810                                 status = finish_port_resume(udev);
1811                 }
1812         }
1813         if (status < 0)
1814                 hub_port_logical_disconnect(hub, port1);
1815
1816         return status;
1817 }
1818
1819 static int hub_resume (struct usb_interface *intf);
1820
1821 /**
1822  * usb_resume_device - re-activate a suspended usb device
1823  * @udev: device to re-activate
1824  * Context: must be able to sleep; device not locked
1825  *
1826  * This will re-activate the suspended device, increasing power usage
1827  * while letting drivers communicate again with its endpoints.
1828  * USB resume explicitly guarantees that the power session between
1829  * the host and the device is the same as it was when the device
1830  * suspended.
1831  *
1832  * Returns 0 on success, else negative errno.
1833  */
1834 int usb_resume_device(struct usb_device *udev)
1835 {
1836         int     port1, status;
1837
1838         port1 = locktree(udev);
1839         if (port1 < 0)
1840                 return port1;
1841
1842         /* "global resume" of the HC-to-USB interface (root hub), or
1843          * selective resume of one hub-to-device port
1844          */
1845         if (!udev->parent) {
1846                 struct usb_bus  *bus = udev->bus;
1847                 if (bus && bus->op->hub_resume) {
1848                         status = bus->op->hub_resume (bus);
1849                 } else
1850                         status = -EOPNOTSUPP;
1851                 if (status == 0) {
1852                         dev_dbg(&udev->dev, "usb resume\n");
1853                         /* TRSMRCY = 10 msec */
1854                         msleep(10);
1855                         usb_set_device_state (udev, USB_STATE_CONFIGURED);
1856                         udev->dev.power.power_state = PMSG_ON;
1857                         status = hub_resume (udev
1858                                         ->actconfig->interface[0]);
1859                 }
1860         } else if (udev->state == USB_STATE_SUSPENDED) {
1861                 // NOTE this fails if parent is also suspended...
1862                 status = hub_port_resume(hdev_to_hub(udev->parent),
1863                                 port1, udev);
1864         } else {
1865                 status = 0;
1866         }
1867         if (status < 0) {
1868                 dev_dbg(&udev->dev, "can't resume, status %d\n",
1869                         status);
1870         }
1871
1872         usb_unlock_device(udev);
1873
1874         /* rebind drivers that had no suspend() */
1875         if (status == 0) {
1876                 usb_lock_all_devices();
1877                 bus_rescan_devices(&usb_bus_type);
1878                 usb_unlock_all_devices();
1879         }
1880         return status;
1881 }
1882
1883 static int remote_wakeup(struct usb_device *udev)
1884 {
1885         int     status = 0;
1886
1887         /* don't repeat RESUME sequence if this device
1888          * was already woken up by some other task
1889          */
1890         down(&udev->serialize);
1891         if (udev->state == USB_STATE_SUSPENDED) {
1892                 dev_dbg(&udev->dev, "RESUME (wakeup)\n");
1893                 /* TRSMRCY = 10 msec */
1894                 msleep(10);
1895                 status = finish_port_resume(udev);
1896         }
1897         up(&udev->serialize);
1898         return status;
1899 }
1900
1901 static int hub_suspend(struct usb_interface *intf, pm_message_t state)
1902 {
1903         struct usb_hub          *hub = usb_get_intfdata (intf);
1904         struct usb_device       *hdev = hub->hdev;
1905         unsigned                port1;
1906         int                     status;
1907
1908         /* stop khubd and related activity */
1909         hub_quiesce(hub);
1910
1911         /* then suspend every port */
1912         for (port1 = 1; port1 <= hdev->maxchild; port1++) {
1913                 struct usb_device       *udev;
1914
1915                 udev = hdev->children [port1-1];
1916                 if (!udev)
1917                         continue;
1918                 down(&udev->serialize);
1919                 status = __usb_suspend_device(udev, port1, state);
1920                 up(&udev->serialize);
1921                 if (status < 0)
1922                         dev_dbg(&intf->dev, "suspend port %d --> %d\n",
1923                                 port1, status);
1924         }
1925
1926         intf->dev.power.power_state = state;
1927         return 0;
1928 }
1929
1930 static int hub_resume(struct usb_interface *intf)
1931 {
1932         struct usb_device       *hdev = interface_to_usbdev(intf);
1933         struct usb_hub          *hub = usb_get_intfdata (intf);
1934         unsigned                port1;
1935         int                     status;
1936
1937         if (intf->dev.power.power_state == PM_SUSPEND_ON)
1938                 return 0;
1939
1940         for (port1 = 1; port1 <= hdev->maxchild; port1++) {
1941                 struct usb_device       *udev;
1942                 u16                     portstat, portchange;
1943
1944                 udev = hdev->children [port1-1];
1945                 status = hub_port_status(hub, port1, &portstat, &portchange);
1946                 if (status == 0) {
1947                         if (portchange & USB_PORT_STAT_C_SUSPEND) {
1948                                 clear_port_feature(hdev, port1,
1949                                         USB_PORT_FEAT_C_SUSPEND);
1950                                 portchange &= ~USB_PORT_STAT_C_SUSPEND;
1951                         }
1952
1953                         /* let khubd handle disconnects etc */
1954                         if (portchange)
1955                                 continue;
1956                 }
1957
1958                 if (!udev || status < 0)
1959                         continue;
1960                 down (&udev->serialize);
1961                 if (portstat & USB_PORT_STAT_SUSPEND)
1962                         status = hub_port_resume(hub, port1, udev);
1963                 else {
1964                         status = finish_port_resume(udev);
1965                         if (status < 0) {
1966                                 dev_dbg(&intf->dev, "resume port %d --> %d\n",
1967                                         port1, status);
1968                                 hub_port_logical_disconnect(hub, port1);
1969                         }
1970                 }
1971                 up(&udev->serialize);
1972         }
1973         intf->dev.power.power_state = PMSG_ON;
1974
1975         hub->resume_root_hub = 0;
1976         hub_activate(hub);
1977         return 0;
1978 }
1979
1980 void usb_resume_root_hub(struct usb_device *hdev)
1981 {
1982         struct usb_hub *hub = hdev_to_hub(hdev);
1983
1984         hub->resume_root_hub = 1;
1985         kick_khubd(hub);
1986 }
1987
1988 #else   /* !CONFIG_USB_SUSPEND */
1989
1990 int usb_suspend_device(struct usb_device *udev, pm_message_t state)
1991 {
1992         return 0;
1993 }
1994
1995 int usb_resume_device(struct usb_device *udev)
1996 {
1997         return 0;
1998 }
1999
2000 #define hub_suspend             NULL
2001 #define hub_resume              NULL
2002 #define remote_wakeup(x)        0
2003
2004 #endif  /* CONFIG_USB_SUSPEND */
2005
2006 EXPORT_SYMBOL(usb_suspend_device);
2007 EXPORT_SYMBOL(usb_resume_device);
2008
2009
2010
2011 /* USB 2.0 spec, 7.1.7.3 / fig 7-29:
2012  *
2013  * Between connect detection and reset signaling there must be a delay
2014  * of 100ms at least for debounce and power-settling.  The corresponding
2015  * timer shall restart whenever the downstream port detects a disconnect.
2016  * 
2017  * Apparently there are some bluetooth and irda-dongles and a number of
2018  * low-speed devices for which this debounce period may last over a second.
2019  * Not covered by the spec - but easy to deal with.
2020  *
2021  * This implementation uses a 1500ms total debounce timeout; if the
2022  * connection isn't stable by then it returns -ETIMEDOUT.  It checks
2023  * every 25ms for transient disconnects.  When the port status has been
2024  * unchanged for 100ms it returns the port status.
2025  */
2026
2027 #define HUB_DEBOUNCE_TIMEOUT    1500
2028 #define HUB_DEBOUNCE_STEP         25
2029 #define HUB_DEBOUNCE_STABLE      100
2030
2031 static int hub_port_debounce(struct usb_hub *hub, int port1)
2032 {
2033         int ret;
2034         int total_time, stable_time = 0;
2035         u16 portchange, portstatus;
2036         unsigned connection = 0xffff;
2037
2038         for (total_time = 0; ; total_time += HUB_DEBOUNCE_STEP) {
2039                 ret = hub_port_status(hub, port1, &portstatus, &portchange);
2040                 if (ret < 0)
2041                         return ret;
2042
2043                 if (!(portchange & USB_PORT_STAT_C_CONNECTION) &&
2044                      (portstatus & USB_PORT_STAT_CONNECTION) == connection) {
2045                         stable_time += HUB_DEBOUNCE_STEP;
2046                         if (stable_time >= HUB_DEBOUNCE_STABLE)
2047                                 break;
2048                 } else {
2049                         stable_time = 0;
2050                         connection = portstatus & USB_PORT_STAT_CONNECTION;
2051                 }
2052
2053                 if (portchange & USB_PORT_STAT_C_CONNECTION) {
2054                         clear_port_feature(hub->hdev, port1,
2055                                         USB_PORT_FEAT_C_CONNECTION);
2056                 }
2057
2058                 if (total_time >= HUB_DEBOUNCE_TIMEOUT)
2059                         break;
2060                 msleep(HUB_DEBOUNCE_STEP);
2061         }
2062
2063         dev_dbg (hub->intfdev,
2064                 "debounce: port %d: total %dms stable %dms status 0x%x\n",
2065                 port1, total_time, stable_time, portstatus);
2066
2067         if (stable_time < HUB_DEBOUNCE_STABLE)
2068                 return -ETIMEDOUT;
2069         return portstatus;
2070 }
2071
2072 static void ep0_reinit(struct usb_device *udev)
2073 {
2074         usb_disable_endpoint(udev, 0 + USB_DIR_IN);
2075         usb_disable_endpoint(udev, 0 + USB_DIR_OUT);
2076         udev->ep_in[0] = udev->ep_out[0] = &udev->ep0;
2077 }
2078
2079 #define usb_sndaddr0pipe()      (PIPE_CONTROL << 30)
2080 #define usb_rcvaddr0pipe()      ((PIPE_CONTROL << 30) | USB_DIR_IN)
2081
2082 static int hub_set_address(struct usb_device *udev)
2083 {
2084         int retval;
2085
2086         if (udev->devnum == 0)
2087                 return -EINVAL;
2088         if (udev->state == USB_STATE_ADDRESS)
2089                 return 0;
2090         if (udev->state != USB_STATE_DEFAULT)
2091                 return -EINVAL;
2092         retval = usb_control_msg(udev, usb_sndaddr0pipe(),
2093                 USB_REQ_SET_ADDRESS, 0, udev->devnum, 0,
2094                 NULL, 0, USB_CTRL_SET_TIMEOUT);
2095         if (retval == 0) {
2096                 usb_set_device_state(udev, USB_STATE_ADDRESS);
2097                 ep0_reinit(udev);
2098         }
2099         return retval;
2100 }
2101
2102 /* Reset device, (re)assign address, get device descriptor.
2103  * Device connection must be stable, no more debouncing needed.
2104  * Returns device in USB_STATE_ADDRESS, except on error.
2105  *
2106  * If this is called for an already-existing device (as part of
2107  * usb_reset_device), the caller must own the device lock.  For a
2108  * newly detected device that is not accessible through any global
2109  * pointers, it's not necessary to lock the device.
2110  */
2111 static int
2112 hub_port_init (struct usb_hub *hub, struct usb_device *udev, int port1,
2113                 int retry_counter)
2114 {
2115         static DECLARE_MUTEX(usb_address0_sem);
2116
2117         struct usb_device       *hdev = hub->hdev;
2118         int                     i, j, retval;
2119         unsigned                delay = HUB_SHORT_RESET_TIME;
2120         enum usb_device_speed   oldspeed = udev->speed;
2121
2122         /* root hub ports have a slightly longer reset period
2123          * (from USB 2.0 spec, section 7.1.7.5)
2124          */
2125         if (!hdev->parent) {
2126                 delay = HUB_ROOT_RESET_TIME;
2127                 if (port1 == hdev->bus->otg_port)
2128                         hdev->bus->b_hnp_enable = 0;
2129         }
2130
2131         /* Some low speed devices have problems with the quick delay, so */
2132         /*  be a bit pessimistic with those devices. RHbug #23670 */
2133         if (oldspeed == USB_SPEED_LOW)
2134                 delay = HUB_LONG_RESET_TIME;
2135
2136         down(&usb_address0_sem);
2137
2138         /* Reset the device; full speed may morph to high speed */
2139         retval = hub_port_reset(hub, port1, udev, delay);
2140         if (retval < 0)         /* error or disconnect */
2141                 goto fail;
2142                                 /* success, speed is known */
2143         retval = -ENODEV;
2144
2145         if (oldspeed != USB_SPEED_UNKNOWN && oldspeed != udev->speed) {
2146                 dev_dbg(&udev->dev, "device reset changed speed!\n");
2147                 goto fail;
2148         }
2149         oldspeed = udev->speed;
2150   
2151         /* USB 2.0 section 5.5.3 talks about ep0 maxpacket ...
2152          * it's fixed size except for full speed devices.
2153          */
2154         switch (udev->speed) {
2155         case USB_SPEED_HIGH:            /* fixed at 64 */
2156                 udev->ep0.desc.wMaxPacketSize = __constant_cpu_to_le16(64);
2157                 break;
2158         case USB_SPEED_FULL:            /* 8, 16, 32, or 64 */
2159                 /* to determine the ep0 maxpacket size, try to read
2160                  * the device descriptor to get bMaxPacketSize0 and
2161                  * then correct our initial guess.
2162                  */
2163                 udev->ep0.desc.wMaxPacketSize = __constant_cpu_to_le16(64);
2164                 break;
2165         case USB_SPEED_LOW:             /* fixed at 8 */
2166                 udev->ep0.desc.wMaxPacketSize = __constant_cpu_to_le16(8);
2167                 break;
2168         default:
2169                 goto fail;
2170         }
2171  
2172         dev_info (&udev->dev,
2173                         "%s %s speed USB device using %s and address %d\n",
2174                         (udev->config) ? "reset" : "new",
2175                         ({ char *speed; switch (udev->speed) {
2176                         case USB_SPEED_LOW:     speed = "low";  break;
2177                         case USB_SPEED_FULL:    speed = "full"; break;
2178                         case USB_SPEED_HIGH:    speed = "high"; break;
2179                         default:                speed = "?";    break;
2180                         }; speed;}),
2181                         udev->bus->controller->driver->name,
2182                         udev->devnum);
2183
2184         /* Set up TT records, if needed  */
2185         if (hdev->tt) {
2186                 udev->tt = hdev->tt;
2187                 udev->ttport = hdev->ttport;
2188         } else if (udev->speed != USB_SPEED_HIGH
2189                         && hdev->speed == USB_SPEED_HIGH) {
2190                 udev->tt = &hub->tt;
2191                 udev->ttport = port1;
2192         }
2193  
2194         /* Why interleave GET_DESCRIPTOR and SET_ADDRESS this way?
2195          * Because device hardware and firmware is sometimes buggy in
2196          * this area, and this is how Linux has done it for ages.
2197          * Change it cautiously.
2198          *
2199          * NOTE:  If USE_NEW_SCHEME() is true we will start by issuing
2200          * a 64-byte GET_DESCRIPTOR request.  This is what Windows does,
2201          * so it may help with some non-standards-compliant devices.
2202          * Otherwise we start with SET_ADDRESS and then try to read the
2203          * first 8 bytes of the device descriptor to get the ep0 maxpacket
2204          * value.
2205          */
2206         for (i = 0; i < GET_DESCRIPTOR_TRIES; (++i, msleep(100))) {
2207                 if (USE_NEW_SCHEME(retry_counter)) {
2208                         struct usb_device_descriptor *buf;
2209                         int r = 0;
2210
2211 #define GET_DESCRIPTOR_BUFSIZE  64
2212                         buf = kmalloc(GET_DESCRIPTOR_BUFSIZE, GFP_NOIO);
2213                         if (!buf) {
2214                                 retval = -ENOMEM;
2215                                 continue;
2216                         }
2217
2218                         /* Use a short timeout the first time through,
2219                          * so that recalcitrant full-speed devices with
2220                          * 8- or 16-byte ep0-maxpackets won't slow things
2221                          * down tremendously by NAKing the unexpectedly
2222                          * early status stage.  Also, retry on all errors;
2223                          * some devices are flakey.
2224                          */
2225                         for (j = 0; j < 3; ++j) {
2226                                 buf->bMaxPacketSize0 = 0;
2227                                 r = usb_control_msg(udev, usb_rcvaddr0pipe(),
2228                                         USB_REQ_GET_DESCRIPTOR, USB_DIR_IN,
2229                                         USB_DT_DEVICE << 8, 0,
2230                                         buf, GET_DESCRIPTOR_BUFSIZE,
2231                                         (i ? USB_CTRL_GET_TIMEOUT : 1000));
2232                                 switch (buf->bMaxPacketSize0) {
2233                                 case 8: case 16: case 32: case 64:
2234                                         if (buf->bDescriptorType ==
2235                                                         USB_DT_DEVICE) {
2236                                                 r = 0;
2237                                                 break;
2238                                         }
2239                                         /* FALL THROUGH */
2240                                 default:
2241                                         if (r == 0)
2242                                                 r = -EPROTO;
2243                                         break;
2244                                 }
2245                                 if (r == 0)
2246                                         break;
2247                         }
2248                         udev->descriptor.bMaxPacketSize0 =
2249                                         buf->bMaxPacketSize0;
2250                         kfree(buf);
2251
2252                         retval = hub_port_reset(hub, port1, udev, delay);
2253                         if (retval < 0)         /* error or disconnect */
2254                                 goto fail;
2255                         if (oldspeed != udev->speed) {
2256                                 dev_dbg(&udev->dev,
2257                                         "device reset changed speed!\n");
2258                                 retval = -ENODEV;
2259                                 goto fail;
2260                         }
2261                         if (r) {
2262                                 dev_err(&udev->dev, "device descriptor "
2263                                                 "read/%s, error %d\n",
2264                                                 "64", r);
2265                                 retval = -EMSGSIZE;
2266                                 continue;
2267                         }
2268 #undef GET_DESCRIPTOR_BUFSIZE
2269                 }
2270
2271                 for (j = 0; j < SET_ADDRESS_TRIES; ++j) {
2272                         retval = hub_set_address(udev);
2273                         if (retval >= 0)
2274                                 break;
2275                         msleep(200);
2276                 }
2277                 if (retval < 0) {
2278                         dev_err(&udev->dev,
2279                                 "device not accepting address %d, error %d\n",
2280                                 udev->devnum, retval);
2281                         goto fail;
2282                 }
2283  
2284                 /* cope with hardware quirkiness:
2285                  *  - let SET_ADDRESS settle, some device hardware wants it
2286                  *  - read ep0 maxpacket even for high and low speed,
2287                  */
2288                 msleep(10);
2289                 if (USE_NEW_SCHEME(retry_counter))
2290                         break;
2291
2292                 retval = usb_get_device_descriptor(udev, 8);
2293                 if (retval < 8) {
2294                         dev_err(&udev->dev, "device descriptor "
2295                                         "read/%s, error %d\n",
2296                                         "8", retval);
2297                         if (retval >= 0)
2298                                 retval = -EMSGSIZE;
2299                 } else {
2300                         retval = 0;
2301                         break;
2302                 }
2303         }
2304         if (retval)
2305                 goto fail;
2306
2307         i = udev->descriptor.bMaxPacketSize0;
2308         if (le16_to_cpu(udev->ep0.desc.wMaxPacketSize) != i) {
2309                 if (udev->speed != USB_SPEED_FULL ||
2310                                 !(i == 8 || i == 16 || i == 32 || i == 64)) {
2311                         dev_err(&udev->dev, "ep0 maxpacket = %d\n", i);
2312                         retval = -EMSGSIZE;
2313                         goto fail;
2314                 }
2315                 dev_dbg(&udev->dev, "ep0 maxpacket = %d\n", i);
2316                 udev->ep0.desc.wMaxPacketSize = cpu_to_le16(i);
2317                 ep0_reinit(udev);
2318         }
2319   
2320         retval = usb_get_device_descriptor(udev, USB_DT_DEVICE_SIZE);
2321         if (retval < (signed)sizeof(udev->descriptor)) {
2322                 dev_err(&udev->dev, "device descriptor read/%s, error %d\n",
2323                         "all", retval);
2324                 if (retval >= 0)
2325                         retval = -ENOMSG;
2326                 goto fail;
2327         }
2328
2329         retval = 0;
2330
2331 fail:
2332         if (retval)
2333                 hub_port_disable(hub, port1, 0);
2334         up(&usb_address0_sem);
2335         return retval;
2336 }
2337
2338 static void
2339 check_highspeed (struct usb_hub *hub, struct usb_device *udev, int port1)
2340 {
2341         struct usb_qualifier_descriptor *qual;
2342         int                             status;
2343
2344         qual = kmalloc (sizeof *qual, SLAB_KERNEL);
2345         if (qual == NULL)
2346                 return;
2347
2348         status = usb_get_descriptor (udev, USB_DT_DEVICE_QUALIFIER, 0,
2349                         qual, sizeof *qual);
2350         if (status == sizeof *qual) {
2351                 dev_info(&udev->dev, "not running at top speed; "
2352                         "connect to a high speed hub\n");
2353                 /* hub LEDs are probably harder to miss than syslog */
2354                 if (hub->has_indicators) {
2355                         hub->indicator[port1-1] = INDICATOR_GREEN_BLINK;
2356                         schedule_work (&hub->leds);
2357                 }
2358         }
2359         kfree(qual);
2360 }
2361
2362 static unsigned
2363 hub_power_remaining (struct usb_hub *hub)
2364 {
2365         struct usb_device *hdev = hub->hdev;
2366         int remaining;
2367         unsigned i;
2368
2369         remaining = hub->power_budget;
2370         if (!remaining)         /* self-powered */
2371                 return 0;
2372
2373         for (i = 0; i < hdev->maxchild; i++) {
2374                 struct usb_device       *udev = hdev->children[i];
2375                 int                     delta, ceiling;
2376
2377                 if (!udev)
2378                         continue;
2379
2380                 /* 100mA per-port ceiling, or 8mA for OTG ports */
2381                 if (i != (udev->bus->otg_port - 1) || hdev->parent)
2382                         ceiling = 50;
2383                 else
2384                         ceiling = 4;
2385
2386                 if (udev->actconfig)
2387                         delta = udev->actconfig->desc.bMaxPower;
2388                 else
2389                         delta = ceiling;
2390                 // dev_dbg(&udev->dev, "budgeted %dmA\n", 2 * delta);
2391                 if (delta > ceiling)
2392                         dev_warn(&udev->dev, "%dmA over %dmA budget!\n",
2393                                 2 * (delta - ceiling), 2 * ceiling);
2394                 remaining -= delta;
2395         }
2396         if (remaining < 0) {
2397                 dev_warn(hub->intfdev,
2398                         "%dmA over power budget!\n",
2399                         -2 * remaining);
2400                 remaining = 0;
2401         }
2402         return remaining;
2403 }
2404
2405 /* Handle physical or logical connection change events.
2406  * This routine is called when:
2407  *      a port connection-change occurs;
2408  *      a port enable-change occurs (often caused by EMI);
2409  *      usb_reset_device() encounters changed descriptors (as from
2410  *              a firmware download)
2411  * caller already locked the hub
2412  */
2413 static void hub_port_connect_change(struct usb_hub *hub, int port1,
2414                                         u16 portstatus, u16 portchange)
2415 {
2416         struct usb_device *hdev = hub->hdev;
2417         struct device *hub_dev = hub->intfdev;
2418         int status, i;
2419  
2420         dev_dbg (hub_dev,
2421                 "port %d, status %04x, change %04x, %s\n",
2422                 port1, portstatus, portchange, portspeed (portstatus));
2423
2424         if (hub->has_indicators) {
2425                 set_port_led(hub, port1, HUB_LED_AUTO);
2426                 hub->indicator[port1-1] = INDICATOR_AUTO;
2427         }
2428  
2429         /* Disconnect any existing devices under this port */
2430         if (hdev->children[port1-1])
2431                 usb_disconnect(&hdev->children[port1-1]);
2432         clear_bit(port1, hub->change_bits);
2433
2434 #ifdef  CONFIG_USB_OTG
2435         /* during HNP, don't repeat the debounce */
2436         if (hdev->bus->is_b_host)
2437                 portchange &= ~USB_PORT_STAT_C_CONNECTION;
2438 #endif
2439
2440         if (portchange & USB_PORT_STAT_C_CONNECTION) {
2441                 status = hub_port_debounce(hub, port1);
2442                 if (status < 0) {
2443                         dev_err (hub_dev,
2444                                 "connect-debounce failed, port %d disabled\n",
2445                                 port1);
2446                         goto done;
2447                 }
2448                 portstatus = status;
2449         }
2450
2451         /* Return now if nothing is connected */
2452         if (!(portstatus & USB_PORT_STAT_CONNECTION)) {
2453
2454                 /* maybe switch power back on (e.g. root hub was reset) */
2455                 if ((hub->descriptor->wHubCharacteristics
2456                                         & HUB_CHAR_LPSM) < 2
2457                                 && !(portstatus & (1 << USB_PORT_FEAT_POWER)))
2458                         set_port_feature(hdev, port1, USB_PORT_FEAT_POWER);
2459  
2460                 if (portstatus & USB_PORT_STAT_ENABLE)
2461                         goto done;
2462                 return;
2463         }
2464
2465 #ifdef  CONFIG_USB_SUSPEND
2466         /* If something is connected, but the port is suspended, wake it up. */
2467         if (portstatus & USB_PORT_STAT_SUSPEND) {
2468                 status = hub_port_resume(hub, port1, NULL);
2469                 if (status < 0) {
2470                         dev_dbg(hub_dev,
2471                                 "can't clear suspend on port %d; %d\n",
2472                                 port1, status);
2473                         goto done;
2474                 }
2475         }
2476 #endif
2477
2478         for (i = 0; i < SET_CONFIG_TRIES; i++) {
2479                 struct usb_device *udev;
2480
2481                 /* reallocate for each attempt, since references
2482                  * to the previous one can escape in various ways
2483                  */
2484                 udev = usb_alloc_dev(hdev, hdev->bus, port1);
2485                 if (!udev) {
2486                         dev_err (hub_dev,
2487                                 "couldn't allocate port %d usb_device\n",
2488                                 port1);
2489                         goto done;
2490                 }
2491
2492                 usb_set_device_state(udev, USB_STATE_POWERED);
2493                 udev->speed = USB_SPEED_UNKNOWN;
2494  
2495                 /* set the address */
2496                 choose_address(udev);
2497                 if (udev->devnum <= 0) {
2498                         status = -ENOTCONN;     /* Don't retry */
2499                         goto loop;
2500                 }
2501
2502                 /* reset and get descriptor */
2503                 status = hub_port_init(hub, udev, port1, i);
2504                 if (status < 0)
2505                         goto loop;
2506
2507                 /* consecutive bus-powered hubs aren't reliable; they can
2508                  * violate the voltage drop budget.  if the new child has
2509                  * a "powered" LED, users should notice we didn't enable it
2510                  * (without reading syslog), even without per-port LEDs
2511                  * on the parent.
2512                  */
2513                 if (udev->descriptor.bDeviceClass == USB_CLASS_HUB
2514                                 && hub->power_budget) {
2515                         u16     devstat;
2516
2517                         status = usb_get_status(udev, USB_RECIP_DEVICE, 0,
2518                                         &devstat);
2519                         if (status < 0) {
2520                                 dev_dbg(&udev->dev, "get status %d ?\n", status);
2521                                 goto loop_disable;
2522                         }
2523                         cpu_to_le16s(&devstat);
2524                         if ((devstat & (1 << USB_DEVICE_SELF_POWERED)) == 0) {
2525                                 dev_err(&udev->dev,
2526                                         "can't connect bus-powered hub "
2527                                         "to this port\n");
2528                                 if (hub->has_indicators) {
2529                                         hub->indicator[port1-1] =
2530                                                 INDICATOR_AMBER_BLINK;
2531                                         schedule_work (&hub->leds);
2532                                 }
2533                                 status = -ENOTCONN;     /* Don't retry */
2534                                 goto loop_disable;
2535                         }
2536                 }
2537  
2538                 /* check for devices running slower than they could */
2539                 if (le16_to_cpu(udev->descriptor.bcdUSB) >= 0x0200
2540                                 && udev->speed == USB_SPEED_FULL
2541                                 && highspeed_hubs != 0)
2542                         check_highspeed (hub, udev, port1);
2543
2544                 /* Store the parent's children[] pointer.  At this point
2545                  * udev becomes globally accessible, although presumably
2546                  * no one will look at it until hdev is unlocked.
2547                  */
2548                 down (&udev->serialize);
2549                 status = 0;
2550
2551                 /* We mustn't add new devices if the parent hub has
2552                  * been disconnected; we would race with the
2553                  * recursively_mark_NOTATTACHED() routine.
2554                  */
2555                 spin_lock_irq(&device_state_lock);
2556                 if (hdev->state == USB_STATE_NOTATTACHED)
2557                         status = -ENOTCONN;
2558                 else
2559                         hdev->children[port1-1] = udev;
2560                 spin_unlock_irq(&device_state_lock);
2561
2562                 /* Run it through the hoops (find a driver, etc) */
2563                 if (!status) {
2564                         status = usb_new_device(udev);
2565                         if (status) {
2566                                 spin_lock_irq(&device_state_lock);
2567                                 hdev->children[port1-1] = NULL;
2568                                 spin_unlock_irq(&device_state_lock);
2569                         }
2570                 }
2571
2572                 up (&udev->serialize);
2573                 if (status)
2574                         goto loop_disable;
2575
2576                 status = hub_power_remaining(hub);
2577                 if (status)
2578                         dev_dbg(hub_dev,
2579                                 "%dmA power budget left\n",
2580                                 2 * status);
2581
2582                 return;
2583
2584 loop_disable:
2585                 hub_port_disable(hub, port1, 1);
2586 loop:
2587                 ep0_reinit(udev);
2588                 release_address(udev);
2589                 usb_put_dev(udev);
2590                 if (status == -ENOTCONN)
2591                         break;
2592         }
2593  
2594 done:
2595         hub_port_disable(hub, port1, 1);
2596 }
2597
2598 static void hub_events(void)
2599 {
2600         struct list_head *tmp;
2601         struct usb_device *hdev;
2602         struct usb_interface *intf;
2603         struct usb_hub *hub;
2604         struct device *hub_dev;
2605         u16 hubstatus;
2606         u16 hubchange;
2607         u16 portstatus;
2608         u16 portchange;
2609         int i, ret;
2610         int connect_change;
2611
2612         /*
2613          *  We restart the list every time to avoid a deadlock with
2614          * deleting hubs downstream from this one. This should be
2615          * safe since we delete the hub from the event list.
2616          * Not the most efficient, but avoids deadlocks.
2617          */
2618         while (1) {
2619
2620                 /* Grab the first entry at the beginning of the list */
2621                 spin_lock_irq(&hub_event_lock);
2622                 if (list_empty(&hub_event_list)) {
2623                         spin_unlock_irq(&hub_event_lock);
2624                         break;
2625                 }
2626
2627                 tmp = hub_event_list.next;
2628                 list_del_init(tmp);
2629
2630                 hub = list_entry(tmp, struct usb_hub, event_list);
2631                 hdev = hub->hdev;
2632                 intf = to_usb_interface(hub->intfdev);
2633                 hub_dev = &intf->dev;
2634
2635                 dev_dbg(hub_dev, "state %d ports %d chg %04x evt %04x\n",
2636                                 hdev->state, hub->descriptor
2637                                         ? hub->descriptor->bNbrPorts
2638                                         : 0,
2639                                 /* NOTE: expects max 15 ports... */
2640                                 (u16) hub->change_bits[0],
2641                                 (u16) hub->event_bits[0]);
2642
2643                 usb_get_intf(intf);
2644                 i = hub->resume_root_hub;
2645                 spin_unlock_irq(&hub_event_lock);
2646
2647                 /* Is this is a root hub wanting to be resumed? */
2648                 if (i)
2649                         usb_resume_device(hdev);
2650
2651                 /* Lock the device, then check to see if we were
2652                  * disconnected while waiting for the lock to succeed. */
2653                 if (locktree(hdev) < 0) {
2654                         usb_put_intf(intf);
2655                         continue;
2656                 }
2657                 if (hub != usb_get_intfdata(intf))
2658                         goto loop;
2659
2660                 /* If the hub has died, clean up after it */
2661                 if (hdev->state == USB_STATE_NOTATTACHED) {
2662                         hub_pre_reset(hub);
2663                         goto loop;
2664                 }
2665
2666                 /* If this is an inactive or suspended hub, do nothing */
2667                 if (hub->quiescing)
2668                         goto loop;
2669
2670                 if (hub->error) {
2671                         dev_dbg (hub_dev, "resetting for error %d\n",
2672                                 hub->error);
2673
2674                         ret = usb_reset_device(hdev);
2675                         if (ret) {
2676                                 dev_dbg (hub_dev,
2677                                         "error resetting hub: %d\n", ret);
2678                                 goto loop;
2679                         }
2680
2681                         hub->nerrors = 0;
2682                         hub->error = 0;
2683                 }
2684
2685                 /* deal with port status changes */
2686                 for (i = 1; i <= hub->descriptor->bNbrPorts; i++) {
2687                         if (test_bit(i, hub->busy_bits))
2688                                 continue;
2689                         connect_change = test_bit(i, hub->change_bits);
2690                         if (!test_and_clear_bit(i, hub->event_bits) &&
2691                                         !connect_change && !hub->activating)
2692                                 continue;
2693
2694                         ret = hub_port_status(hub, i,
2695                                         &portstatus, &portchange);
2696                         if (ret < 0)
2697                                 continue;
2698
2699                         if (hub->activating && !hdev->children[i-1] &&
2700                                         (portstatus &
2701                                                 USB_PORT_STAT_CONNECTION))
2702                                 connect_change = 1;
2703
2704                         if (portchange & USB_PORT_STAT_C_CONNECTION) {
2705                                 clear_port_feature(hdev, i,
2706                                         USB_PORT_FEAT_C_CONNECTION);
2707                                 connect_change = 1;
2708                         }
2709
2710                         if (portchange & USB_PORT_STAT_C_ENABLE) {
2711                                 if (!connect_change)
2712                                         dev_dbg (hub_dev,
2713                                                 "port %d enable change, "
2714                                                 "status %08x\n",
2715                                                 i, portstatus);
2716                                 clear_port_feature(hdev, i,
2717                                         USB_PORT_FEAT_C_ENABLE);
2718
2719                                 /*
2720                                  * EM interference sometimes causes badly
2721                                  * shielded USB devices to be shutdown by
2722                                  * the hub, this hack enables them again.
2723                                  * Works at least with mouse driver. 
2724                                  */
2725                                 if (!(portstatus & USB_PORT_STAT_ENABLE)
2726                                     && !connect_change
2727                                     && hdev->children[i-1]) {
2728                                         dev_err (hub_dev,
2729                                             "port %i "
2730                                             "disabled by hub (EMI?), "
2731                                             "re-enabling...\n",
2732                                                 i);
2733                                         connect_change = 1;
2734                                 }
2735                         }
2736
2737                         if (portchange & USB_PORT_STAT_C_SUSPEND) {
2738                                 clear_port_feature(hdev, i,
2739                                         USB_PORT_FEAT_C_SUSPEND);
2740                                 if (hdev->children[i-1]) {
2741                                         ret = remote_wakeup(hdev->
2742                                                         children[i-1]);
2743                                         if (ret < 0)
2744                                                 connect_change = 1;
2745                                 } else {
2746                                         ret = -ENODEV;
2747                                         hub_port_disable(hub, i, 1);
2748                                 }
2749                                 dev_dbg (hub_dev,
2750                                         "resume on port %d, status %d\n",
2751                                         i, ret);
2752                         }
2753                         
2754                         if (portchange & USB_PORT_STAT_C_OVERCURRENT) {
2755                                 dev_err (hub_dev,
2756                                         "over-current change on port %d\n",
2757                                         i);
2758                                 clear_port_feature(hdev, i,
2759                                         USB_PORT_FEAT_C_OVER_CURRENT);
2760                                 hub_power_on(hub);
2761                         }
2762
2763                         if (portchange & USB_PORT_STAT_C_RESET) {
2764                                 dev_dbg (hub_dev,
2765                                         "reset change on port %d\n",
2766                                         i);
2767                                 clear_port_feature(hdev, i,
2768                                         USB_PORT_FEAT_C_RESET);
2769                         }
2770
2771                         if (connect_change)
2772                                 hub_port_connect_change(hub, i,
2773                                                 portstatus, portchange);
2774                 } /* end for i */
2775
2776                 /* deal with hub status changes */
2777                 if (test_and_clear_bit(0, hub->event_bits) == 0)
2778                         ;       /* do nothing */
2779                 else if (hub_hub_status(hub, &hubstatus, &hubchange) < 0)
2780                         dev_err (hub_dev, "get_hub_status failed\n");
2781                 else {
2782                         if (hubchange & HUB_CHANGE_LOCAL_POWER) {
2783                                 dev_dbg (hub_dev, "power change\n");
2784                                 clear_hub_feature(hdev, C_HUB_LOCAL_POWER);
2785                         }
2786                         if (hubchange & HUB_CHANGE_OVERCURRENT) {
2787                                 dev_dbg (hub_dev, "overcurrent change\n");
2788                                 msleep(500);    /* Cool down */
2789                                 clear_hub_feature(hdev, C_HUB_OVER_CURRENT);
2790                                 hub_power_on(hub);
2791                         }
2792                 }
2793
2794                 hub->activating = 0;
2795
2796                 /* If this is a root hub, tell the HCD it's okay to
2797                  * re-enable port-change interrupts now. */
2798                 if (!hdev->parent)
2799                         usb_enable_root_hub_irq(hdev->bus);
2800
2801 loop:
2802                 usb_unlock_device(hdev);
2803                 usb_put_intf(intf);
2804
2805         } /* end while (1) */
2806 }
2807
2808 static int hub_thread(void *__unused)
2809 {
2810         do {
2811                 hub_events();
2812                 wait_event_interruptible(khubd_wait,
2813                                 !list_empty(&hub_event_list) ||
2814                                 kthread_should_stop());
2815                 try_to_freeze();
2816         } while (!kthread_should_stop() || !list_empty(&hub_event_list));
2817
2818         pr_debug("%s: khubd exiting\n", usbcore_name);
2819         return 0;
2820 }
2821
2822 static struct usb_device_id hub_id_table [] = {
2823     { .match_flags = USB_DEVICE_ID_MATCH_DEV_CLASS,
2824       .bDeviceClass = USB_CLASS_HUB},
2825     { .match_flags = USB_DEVICE_ID_MATCH_INT_CLASS,
2826       .bInterfaceClass = USB_CLASS_HUB},
2827     { }                                         /* Terminating entry */
2828 };
2829
2830 MODULE_DEVICE_TABLE (usb, hub_id_table);
2831
2832 static struct usb_driver hub_driver = {
2833         .owner =        THIS_MODULE,
2834         .name =         "hub",
2835         .probe =        hub_probe,
2836         .disconnect =   hub_disconnect,
2837         .suspend =      hub_suspend,
2838         .resume =       hub_resume,
2839         .ioctl =        hub_ioctl,
2840         .id_table =     hub_id_table,
2841 };
2842
2843 int usb_hub_init(void)
2844 {
2845         if (usb_register(&hub_driver) < 0) {
2846                 printk(KERN_ERR "%s: can't register hub driver\n",
2847                         usbcore_name);
2848                 return -1;
2849         }
2850
2851         khubd_task = kthread_run(hub_thread, NULL, "khubd");
2852         if (!IS_ERR(khubd_task))
2853                 return 0;
2854
2855         /* Fall through if kernel_thread failed */
2856         usb_deregister(&hub_driver);
2857         printk(KERN_ERR "%s: can't start khubd\n", usbcore_name);
2858
2859         return -1;
2860 }
2861
2862 void usb_hub_cleanup(void)
2863 {
2864         kthread_stop(khubd_task);
2865
2866         /*
2867          * Hub resources are freed for us by usb_deregister. It calls
2868          * usb_driver_purge on every device which in turn calls that
2869          * devices disconnect function if it is using this driver.
2870          * The hub_disconnect function takes care of releasing the
2871          * individual hub resources. -greg
2872          */
2873         usb_deregister(&hub_driver);
2874 } /* usb_hub_cleanup() */
2875
2876 static int config_descriptors_changed(struct usb_device *udev)
2877 {
2878         unsigned                        index;
2879         unsigned                        len = 0;
2880         struct usb_config_descriptor    *buf;
2881
2882         for (index = 0; index < udev->descriptor.bNumConfigurations; index++) {
2883                 if (len < le16_to_cpu(udev->config[index].desc.wTotalLength))
2884                         len = le16_to_cpu(udev->config[index].desc.wTotalLength);
2885         }
2886         buf = kmalloc (len, SLAB_KERNEL);
2887         if (buf == NULL) {
2888                 dev_err(&udev->dev, "no mem to re-read configs after reset\n");
2889                 /* assume the worst */
2890                 return 1;
2891         }
2892         for (index = 0; index < udev->descriptor.bNumConfigurations; index++) {
2893                 int length;
2894                 int old_length = le16_to_cpu(udev->config[index].desc.wTotalLength);
2895
2896                 length = usb_get_descriptor(udev, USB_DT_CONFIG, index, buf,
2897                                 old_length);
2898                 if (length < old_length) {
2899                         dev_dbg(&udev->dev, "config index %d, error %d\n",
2900                                         index, length);
2901                         break;
2902                 }
2903                 if (memcmp (buf, udev->rawdescriptors[index], old_length)
2904                                 != 0) {
2905                         dev_dbg(&udev->dev, "config index %d changed (#%d)\n",
2906                                 index, buf->bConfigurationValue);
2907                         break;
2908                 }
2909         }
2910         kfree(buf);
2911         return index != udev->descriptor.bNumConfigurations;
2912 }
2913
2914 /**
2915  * usb_reset_device - perform a USB port reset to reinitialize a device
2916  * @udev: device to reset (not in SUSPENDED or NOTATTACHED state)
2917  *
2918  * WARNING - don't reset any device unless drivers for all of its
2919  * interfaces are expecting that reset!  Maybe some driver->reset()
2920  * method should eventually help ensure sufficient cooperation.
2921  *
2922  * Do a port reset, reassign the device's address, and establish its
2923  * former operating configuration.  If the reset fails, or the device's
2924  * descriptors change from their values before the reset, or the original
2925  * configuration and altsettings cannot be restored, a flag will be set
2926  * telling khubd to pretend the device has been disconnected and then
2927  * re-connected.  All drivers will be unbound, and the device will be
2928  * re-enumerated and probed all over again.
2929  *
2930  * Returns 0 if the reset succeeded, -ENODEV if the device has been
2931  * flagged for logical disconnection, or some other negative error code
2932  * if the reset wasn't even attempted.
2933  *
2934  * The caller must own the device lock.  For example, it's safe to use
2935  * this from a driver probe() routine after downloading new firmware.
2936  * For calls that might not occur during probe(), drivers should lock
2937  * the device using usb_lock_device_for_reset().
2938  */
2939 int usb_reset_device(struct usb_device *udev)
2940 {
2941         struct usb_device               *parent_hdev = udev->parent;
2942         struct usb_hub                  *parent_hub;
2943         struct usb_device_descriptor    descriptor = udev->descriptor;
2944         struct usb_hub                  *hub = NULL;
2945         int                             i, ret = 0, port1 = -1;
2946
2947         if (udev->state == USB_STATE_NOTATTACHED ||
2948                         udev->state == USB_STATE_SUSPENDED) {
2949                 dev_dbg(&udev->dev, "device reset not allowed in state %d\n",
2950                                 udev->state);
2951                 return -EINVAL;
2952         }
2953
2954         if (!parent_hdev) {
2955                 /* this requires hcd-specific logic; see OHCI hc_restart() */
2956                 dev_dbg(&udev->dev, "%s for root hub!\n", __FUNCTION__);
2957                 return -EISDIR;
2958         }
2959
2960         for (i = 0; i < parent_hdev->maxchild; i++)
2961                 if (parent_hdev->children[i] == udev) {
2962                         port1 = i + 1;
2963                         break;
2964                 }
2965
2966         if (port1 < 0) {
2967                 /* If this ever happens, it's very bad */
2968                 dev_err(&udev->dev, "Can't locate device's port!\n");
2969                 return -ENOENT;
2970         }
2971         parent_hub = hdev_to_hub(parent_hdev);
2972
2973         /* If we're resetting an active hub, take some special actions */
2974         if (udev->actconfig &&
2975                         udev->actconfig->interface[0]->dev.driver ==
2976                                 &hub_driver.driver &&
2977                         (hub = hdev_to_hub(udev)) != NULL) {
2978                 hub_pre_reset(hub);
2979         }
2980
2981         set_bit(port1, parent_hub->busy_bits);
2982         for (i = 0; i < SET_CONFIG_TRIES; ++i) {
2983
2984                 /* ep0 maxpacket size may change; let the HCD know about it.
2985                  * Other endpoints will be handled by re-enumeration. */
2986                 ep0_reinit(udev);
2987                 ret = hub_port_init(parent_hub, udev, port1, i);
2988                 if (ret >= 0)
2989                         break;
2990         }
2991         clear_bit(port1, parent_hub->busy_bits);
2992         if (ret < 0)
2993                 goto re_enumerate;
2994  
2995         /* Device might have changed firmware (DFU or similar) */
2996         if (memcmp(&udev->descriptor, &descriptor, sizeof descriptor)
2997                         || config_descriptors_changed (udev)) {
2998                 dev_info(&udev->dev, "device firmware changed\n");
2999                 udev->descriptor = descriptor;  /* for disconnect() calls */
3000                 goto re_enumerate;
3001         }
3002   
3003         if (!udev->actconfig)
3004                 goto done;
3005
3006         ret = usb_control_msg(udev, usb_sndctrlpipe(udev, 0),
3007                         USB_REQ_SET_CONFIGURATION, 0,
3008                         udev->actconfig->desc.bConfigurationValue, 0,
3009                         NULL, 0, USB_CTRL_SET_TIMEOUT);
3010         if (ret < 0) {
3011                 dev_err(&udev->dev,
3012                         "can't restore configuration #%d (error=%d)\n",
3013                         udev->actconfig->desc.bConfigurationValue, ret);
3014                 goto re_enumerate;
3015         }
3016         usb_set_device_state(udev, USB_STATE_CONFIGURED);
3017
3018         for (i = 0; i < udev->actconfig->desc.bNumInterfaces; i++) {
3019                 struct usb_interface *intf = udev->actconfig->interface[i];
3020                 struct usb_interface_descriptor *desc;
3021
3022                 /* set_interface resets host side toggle even
3023                  * for altsetting zero.  the interface may have no driver.
3024                  */
3025                 desc = &intf->cur_altsetting->desc;
3026                 ret = usb_set_interface(udev, desc->bInterfaceNumber,
3027                         desc->bAlternateSetting);
3028                 if (ret < 0) {
3029                         dev_err(&udev->dev, "failed to restore interface %d "
3030                                 "altsetting %d (error=%d)\n",
3031                                 desc->bInterfaceNumber,
3032                                 desc->bAlternateSetting,
3033                                 ret);
3034                         goto re_enumerate;
3035                 }
3036         }
3037
3038 done:
3039         if (hub)
3040                 hub_post_reset(hub);
3041         return 0;
3042  
3043 re_enumerate:
3044         hub_port_logical_disconnect(parent_hub, port1);
3045         return -ENODEV;
3046 }