ide: don't enable IORDY at a probe time
[linux-2.6.git] / drivers / ide / ide-atapi.c
1 /*
2  * ATAPI support.
3  */
4
5 #include <linux/kernel.h>
6 #include <linux/cdrom.h>
7 #include <linux/delay.h>
8 #include <linux/ide.h>
9 #include <linux/scatterlist.h>
10
11 #include <scsi/scsi.h>
12
13 #define DRV_NAME "ide-atapi"
14 #define PFX DRV_NAME ": "
15
16 #ifdef DEBUG
17 #define debug_log(fmt, args...) \
18         printk(KERN_INFO "ide: " fmt, ## args)
19 #else
20 #define debug_log(fmt, args...) do {} while (0)
21 #endif
22
23 #define ATAPI_MIN_CDB_BYTES     12
24
25 static inline int dev_is_idecd(ide_drive_t *drive)
26 {
27         return drive->media == ide_cdrom || drive->media == ide_optical;
28 }
29
30 /*
31  * Check whether we can support a device,
32  * based on the ATAPI IDENTIFY command results.
33  */
34 int ide_check_atapi_device(ide_drive_t *drive, const char *s)
35 {
36         u16 *id = drive->id;
37         u8 gcw[2], protocol, device_type, removable, drq_type, packet_size;
38
39         *((u16 *)&gcw) = id[ATA_ID_CONFIG];
40
41         protocol    = (gcw[1] & 0xC0) >> 6;
42         device_type =  gcw[1] & 0x1F;
43         removable   = (gcw[0] & 0x80) >> 7;
44         drq_type    = (gcw[0] & 0x60) >> 5;
45         packet_size =  gcw[0] & 0x03;
46
47 #ifdef CONFIG_PPC
48         /* kludge for Apple PowerBook internal zip */
49         if (drive->media == ide_floppy && device_type == 5 &&
50             !strstr((char *)&id[ATA_ID_PROD], "CD-ROM") &&
51             strstr((char *)&id[ATA_ID_PROD], "ZIP"))
52                 device_type = 0;
53 #endif
54
55         if (protocol != 2)
56                 printk(KERN_ERR "%s: %s: protocol (0x%02x) is not ATAPI\n",
57                         s, drive->name, protocol);
58         else if ((drive->media == ide_floppy && device_type != 0) ||
59                  (drive->media == ide_tape && device_type != 1))
60                 printk(KERN_ERR "%s: %s: invalid device type (0x%02x)\n",
61                         s, drive->name, device_type);
62         else if (removable == 0)
63                 printk(KERN_ERR "%s: %s: the removable flag is not set\n",
64                         s, drive->name);
65         else if (drive->media == ide_floppy && drq_type == 3)
66                 printk(KERN_ERR "%s: %s: sorry, DRQ type (0x%02x) not "
67                         "supported\n", s, drive->name, drq_type);
68         else if (packet_size != 0)
69                 printk(KERN_ERR "%s: %s: packet size (0x%02x) is not 12 "
70                         "bytes\n", s, drive->name, packet_size);
71         else
72                 return 1;
73         return 0;
74 }
75 EXPORT_SYMBOL_GPL(ide_check_atapi_device);
76
77 void ide_init_pc(struct ide_atapi_pc *pc)
78 {
79         memset(pc, 0, sizeof(*pc));
80 }
81 EXPORT_SYMBOL_GPL(ide_init_pc);
82
83 /*
84  * Add a special packet command request to the tail of the request queue,
85  * and wait for it to be serviced.
86  */
87 int ide_queue_pc_tail(ide_drive_t *drive, struct gendisk *disk,
88                       struct ide_atapi_pc *pc, void *buf, unsigned int bufflen)
89 {
90         struct request *rq;
91         int error;
92
93         rq = blk_get_request(drive->queue, READ, __GFP_WAIT);
94         rq->cmd_type = REQ_TYPE_SPECIAL;
95         rq->special = (char *)pc;
96
97         if (buf && bufflen) {
98                 error = blk_rq_map_kern(drive->queue, rq, buf, bufflen,
99                                         GFP_NOIO);
100                 if (error)
101                         goto put_req;
102         }
103
104         memcpy(rq->cmd, pc->c, 12);
105         if (drive->media == ide_tape)
106                 rq->cmd[13] = REQ_IDETAPE_PC1;
107         error = blk_execute_rq(drive->queue, disk, rq, 0);
108 put_req:
109         blk_put_request(rq);
110         return error;
111 }
112 EXPORT_SYMBOL_GPL(ide_queue_pc_tail);
113
114 int ide_do_test_unit_ready(ide_drive_t *drive, struct gendisk *disk)
115 {
116         struct ide_atapi_pc pc;
117
118         ide_init_pc(&pc);
119         pc.c[0] = TEST_UNIT_READY;
120
121         return ide_queue_pc_tail(drive, disk, &pc, NULL, 0);
122 }
123 EXPORT_SYMBOL_GPL(ide_do_test_unit_ready);
124
125 int ide_do_start_stop(ide_drive_t *drive, struct gendisk *disk, int start)
126 {
127         struct ide_atapi_pc pc;
128
129         ide_init_pc(&pc);
130         pc.c[0] = START_STOP;
131         pc.c[4] = start;
132
133         if (drive->media == ide_tape)
134                 pc.flags |= PC_FLAG_WAIT_FOR_DSC;
135
136         return ide_queue_pc_tail(drive, disk, &pc, NULL, 0);
137 }
138 EXPORT_SYMBOL_GPL(ide_do_start_stop);
139
140 int ide_set_media_lock(ide_drive_t *drive, struct gendisk *disk, int on)
141 {
142         struct ide_atapi_pc pc;
143
144         if ((drive->dev_flags & IDE_DFLAG_DOORLOCKING) == 0)
145                 return 0;
146
147         ide_init_pc(&pc);
148         pc.c[0] = ALLOW_MEDIUM_REMOVAL;
149         pc.c[4] = on;
150
151         return ide_queue_pc_tail(drive, disk, &pc, NULL, 0);
152 }
153 EXPORT_SYMBOL_GPL(ide_set_media_lock);
154
155 void ide_create_request_sense_cmd(ide_drive_t *drive, struct ide_atapi_pc *pc)
156 {
157         ide_init_pc(pc);
158         pc->c[0] = REQUEST_SENSE;
159         if (drive->media == ide_floppy) {
160                 pc->c[4] = 255;
161                 pc->req_xfer = 18;
162         } else {
163                 pc->c[4] = 20;
164                 pc->req_xfer = 20;
165         }
166 }
167 EXPORT_SYMBOL_GPL(ide_create_request_sense_cmd);
168
169 void ide_prep_sense(ide_drive_t *drive, struct request *rq)
170 {
171         struct request_sense *sense = &drive->sense_data;
172         struct request *sense_rq = &drive->sense_rq;
173         unsigned int cmd_len, sense_len;
174         int err;
175
176         switch (drive->media) {
177         case ide_floppy:
178                 cmd_len = 255;
179                 sense_len = 18;
180                 break;
181         case ide_tape:
182                 cmd_len = 20;
183                 sense_len = 20;
184                 break;
185         default:
186                 cmd_len = 18;
187                 sense_len = 18;
188         }
189
190         BUG_ON(sense_len > sizeof(*sense));
191
192         if (blk_sense_request(rq) || drive->sense_rq_armed)
193                 return;
194
195         memset(sense, 0, sizeof(*sense));
196
197         blk_rq_init(rq->q, sense_rq);
198
199         err = blk_rq_map_kern(drive->queue, sense_rq, sense, sense_len,
200                               GFP_NOIO);
201         if (unlikely(err)) {
202                 if (printk_ratelimit())
203                         printk(KERN_WARNING PFX "%s: failed to map sense "
204                                             "buffer\n", drive->name);
205                 return;
206         }
207
208         sense_rq->rq_disk = rq->rq_disk;
209         sense_rq->cmd[0] = GPCMD_REQUEST_SENSE;
210         sense_rq->cmd[4] = cmd_len;
211         sense_rq->cmd_type = REQ_TYPE_SENSE;
212         sense_rq->cmd_flags |= REQ_PREEMPT;
213
214         if (drive->media == ide_tape)
215                 sense_rq->cmd[13] = REQ_IDETAPE_PC1;
216
217         drive->sense_rq_armed = true;
218 }
219 EXPORT_SYMBOL_GPL(ide_prep_sense);
220
221 int ide_queue_sense_rq(ide_drive_t *drive, void *special)
222 {
223         /* deferred failure from ide_prep_sense() */
224         if (!drive->sense_rq_armed) {
225                 printk(KERN_WARNING PFX "%s: error queuing a sense request\n",
226                        drive->name);
227                 return -ENOMEM;
228         }
229
230         drive->sense_rq.special = special;
231         drive->sense_rq_armed = false;
232
233         drive->hwif->rq = NULL;
234
235         elv_add_request(drive->queue, &drive->sense_rq,
236                         ELEVATOR_INSERT_FRONT, 0);
237         return 0;
238 }
239 EXPORT_SYMBOL_GPL(ide_queue_sense_rq);
240
241 /*
242  * Called when an error was detected during the last packet command.
243  * We queue a request sense packet command at the head of the request
244  * queue.
245  */
246 void ide_retry_pc(ide_drive_t *drive)
247 {
248         struct request *failed_rq = drive->hwif->rq;
249         struct request *sense_rq = &drive->sense_rq;
250         struct ide_atapi_pc *pc = &drive->request_sense_pc;
251
252         (void)ide_read_error(drive);
253
254         /* init pc from sense_rq */
255         ide_init_pc(pc);
256         memcpy(pc->c, sense_rq->cmd, 12);
257
258         if (drive->media == ide_tape)
259                 drive->atapi_flags |= IDE_AFLAG_IGNORE_DSC;
260
261         /*
262          * Push back the failed request and put request sense on top
263          * of it.  The failed command will be retried after sense data
264          * is acquired.
265          */
266         blk_requeue_request(failed_rq->q, failed_rq);
267         drive->hwif->rq = NULL;
268         if (ide_queue_sense_rq(drive, pc)) {
269                 blk_start_request(failed_rq);
270                 ide_complete_rq(drive, -EIO, blk_rq_bytes(failed_rq));
271         }
272 }
273 EXPORT_SYMBOL_GPL(ide_retry_pc);
274
275 int ide_cd_expiry(ide_drive_t *drive)
276 {
277         struct request *rq = drive->hwif->rq;
278         unsigned long wait = 0;
279
280         debug_log("%s: rq->cmd[0]: 0x%x\n", __func__, rq->cmd[0]);
281
282         /*
283          * Some commands are *slow* and normally take a long time to complete.
284          * Usually we can use the ATAPI "disconnect" to bypass this, but not all
285          * commands/drives support that. Let ide_timer_expiry keep polling us
286          * for these.
287          */
288         switch (rq->cmd[0]) {
289         case GPCMD_BLANK:
290         case GPCMD_FORMAT_UNIT:
291         case GPCMD_RESERVE_RZONE_TRACK:
292         case GPCMD_CLOSE_TRACK:
293         case GPCMD_FLUSH_CACHE:
294                 wait = ATAPI_WAIT_PC;
295                 break;
296         default:
297                 if (!(rq->cmd_flags & REQ_QUIET))
298                         printk(KERN_INFO PFX "cmd 0x%x timed out\n",
299                                          rq->cmd[0]);
300                 wait = 0;
301                 break;
302         }
303         return wait;
304 }
305 EXPORT_SYMBOL_GPL(ide_cd_expiry);
306
307 int ide_cd_get_xferlen(struct request *rq)
308 {
309         if (blk_fs_request(rq))
310                 return 32768;
311         else if (blk_sense_request(rq) || blk_pc_request(rq) ||
312                          rq->cmd_type == REQ_TYPE_ATA_PC)
313                 return blk_rq_bytes(rq);
314         else
315                 return 0;
316 }
317 EXPORT_SYMBOL_GPL(ide_cd_get_xferlen);
318
319 void ide_read_bcount_and_ireason(ide_drive_t *drive, u16 *bcount, u8 *ireason)
320 {
321         struct ide_taskfile tf;
322
323         drive->hwif->tp_ops->tf_read(drive, &tf, IDE_VALID_NSECT |
324                                      IDE_VALID_LBAM | IDE_VALID_LBAH);
325
326         *bcount = (tf.lbah << 8) | tf.lbam;
327         *ireason = tf.nsect & 3;
328 }
329 EXPORT_SYMBOL_GPL(ide_read_bcount_and_ireason);
330
331 /*
332  * Check the contents of the interrupt reason register and attempt to recover if
333  * there are problems.
334  *
335  * Returns:
336  * - 0 if everything's ok
337  * - 1 if the request has to be terminated.
338  */
339 int ide_check_ireason(ide_drive_t *drive, struct request *rq, int len,
340                       int ireason, int rw)
341 {
342         ide_hwif_t *hwif = drive->hwif;
343
344         debug_log("ireason: 0x%x, rw: 0x%x\n", ireason, rw);
345
346         if (ireason == (!rw << 1))
347                 return 0;
348         else if (ireason == (rw << 1)) {
349                 printk(KERN_ERR PFX "%s: %s: wrong transfer direction!\n",
350                                 drive->name, __func__);
351
352                 if (dev_is_idecd(drive))
353                         ide_pad_transfer(drive, rw, len);
354         } else if (!rw && ireason == ATAPI_COD) {
355                 if (dev_is_idecd(drive)) {
356                         /*
357                          * Some drives (ASUS) seem to tell us that status info
358                          * is available.  Just get it and ignore.
359                          */
360                         (void)hwif->tp_ops->read_status(hwif);
361                         return 0;
362                 }
363         } else {
364                 if (ireason & ATAPI_COD)
365                         printk(KERN_ERR PFX "%s: CoD != 0 in %s\n", drive->name,
366                                         __func__);
367
368                 /* drive wants a command packet, or invalid ireason... */
369                 printk(KERN_ERR PFX "%s: %s: bad interrupt reason 0x%02x\n",
370                                 drive->name, __func__, ireason);
371         }
372
373         if (dev_is_idecd(drive) && rq->cmd_type == REQ_TYPE_ATA_PC)
374                 rq->cmd_flags |= REQ_FAILED;
375
376         return 1;
377 }
378 EXPORT_SYMBOL_GPL(ide_check_ireason);
379
380 /*
381  * This is the usual interrupt handler which will be called during a packet
382  * command.  We will transfer some of the data (as requested by the drive)
383  * and will re-point interrupt handler to us.
384  */
385 static ide_startstop_t ide_pc_intr(ide_drive_t *drive)
386 {
387         struct ide_atapi_pc *pc = drive->pc;
388         ide_hwif_t *hwif = drive->hwif;
389         struct ide_cmd *cmd = &hwif->cmd;
390         struct request *rq = hwif->rq;
391         const struct ide_tp_ops *tp_ops = hwif->tp_ops;
392         unsigned int timeout, done;
393         u16 bcount;
394         u8 stat, ireason, dsc = 0;
395         u8 write = !!(pc->flags & PC_FLAG_WRITING);
396
397         debug_log("Enter %s - interrupt handler\n", __func__);
398
399         timeout = (drive->media == ide_floppy) ? WAIT_FLOPPY_CMD
400                                                : WAIT_TAPE_CMD;
401
402         /* Clear the interrupt */
403         stat = tp_ops->read_status(hwif);
404
405         if (pc->flags & PC_FLAG_DMA_IN_PROGRESS) {
406                 int rc;
407
408                 drive->waiting_for_dma = 0;
409                 rc = hwif->dma_ops->dma_end(drive);
410                 ide_dma_unmap_sg(drive, cmd);
411
412                 if (rc || (drive->media == ide_tape && (stat & ATA_ERR))) {
413                         if (drive->media == ide_floppy)
414                                 printk(KERN_ERR PFX "%s: DMA %s error\n",
415                                         drive->name, rq_data_dir(pc->rq)
416                                                      ? "write" : "read");
417                         pc->flags |= PC_FLAG_DMA_ERROR;
418                 } else
419                         rq->resid_len = 0;
420                 debug_log("%s: DMA finished\n", drive->name);
421         }
422
423         /* No more interrupts */
424         if ((stat & ATA_DRQ) == 0) {
425                 int uptodate, error;
426
427                 debug_log("Packet command completed, %d bytes transferred\n",
428                           blk_rq_bytes(rq));
429
430                 pc->flags &= ~PC_FLAG_DMA_IN_PROGRESS;
431
432                 local_irq_enable_in_hardirq();
433
434                 if (drive->media == ide_tape &&
435                     (stat & ATA_ERR) && rq->cmd[0] == REQUEST_SENSE)
436                         stat &= ~ATA_ERR;
437
438                 if ((stat & ATA_ERR) || (pc->flags & PC_FLAG_DMA_ERROR)) {
439                         /* Error detected */
440                         debug_log("%s: I/O error\n", drive->name);
441
442                         if (drive->media != ide_tape)
443                                 pc->rq->errors++;
444
445                         if (rq->cmd[0] == REQUEST_SENSE) {
446                                 printk(KERN_ERR PFX "%s: I/O error in request "
447                                                 "sense command\n", drive->name);
448                                 return ide_do_reset(drive);
449                         }
450
451                         debug_log("[cmd %x]: check condition\n", rq->cmd[0]);
452
453                         /* Retry operation */
454                         ide_retry_pc(drive);
455
456                         /* queued, but not started */
457                         return ide_stopped;
458                 }
459                 pc->error = 0;
460
461                 if ((pc->flags & PC_FLAG_WAIT_FOR_DSC) && (stat & ATA_DSC) == 0)
462                         dsc = 1;
463
464                 /*
465                  * ->pc_callback() might change rq->data_len for
466                  * residual count, cache total length.
467                  */
468                 done = blk_rq_bytes(rq);
469
470                 /* Command finished - Call the callback function */
471                 uptodate = drive->pc_callback(drive, dsc);
472
473                 if (uptodate == 0)
474                         drive->failed_pc = NULL;
475
476                 if (blk_special_request(rq)) {
477                         rq->errors = 0;
478                         error = 0;
479                 } else {
480
481                         if (blk_fs_request(rq) == 0 && uptodate <= 0) {
482                                 if (rq->errors == 0)
483                                         rq->errors = -EIO;
484                         }
485
486                         error = uptodate ? 0 : -EIO;
487                 }
488
489                 ide_complete_rq(drive, error, blk_rq_bytes(rq));
490                 return ide_stopped;
491         }
492
493         if (pc->flags & PC_FLAG_DMA_IN_PROGRESS) {
494                 pc->flags &= ~PC_FLAG_DMA_IN_PROGRESS;
495                 printk(KERN_ERR PFX "%s: The device wants to issue more "
496                                 "interrupts in DMA mode\n", drive->name);
497                 ide_dma_off(drive);
498                 return ide_do_reset(drive);
499         }
500
501         /* Get the number of bytes to transfer on this interrupt. */
502         ide_read_bcount_and_ireason(drive, &bcount, &ireason);
503
504         if (ide_check_ireason(drive, rq, bcount, ireason, write))
505                 return ide_do_reset(drive);
506
507         done = min_t(unsigned int, bcount, cmd->nleft);
508         ide_pio_bytes(drive, cmd, write, done);
509
510         /* Update transferred byte count */
511         rq->resid_len -= done;
512
513         bcount -= done;
514
515         if (bcount)
516                 ide_pad_transfer(drive, write, bcount);
517
518         debug_log("[cmd %x] transferred %d bytes, padded %d bytes, resid: %u\n",
519                   rq->cmd[0], done, bcount, rq->resid_len);
520
521         /* And set the interrupt handler again */
522         ide_set_handler(drive, ide_pc_intr, timeout);
523         return ide_started;
524 }
525
526 static void ide_init_packet_cmd(struct ide_cmd *cmd, u8 valid_tf,
527                                 u16 bcount, u8 dma)
528 {
529         cmd->protocol = dma ? ATAPI_PROT_DMA : ATAPI_PROT_PIO;
530         cmd->valid.out.tf = IDE_VALID_LBAH | IDE_VALID_LBAM |
531                             IDE_VALID_FEATURE | valid_tf;
532         cmd->tf.command = ATA_CMD_PACKET;
533         cmd->tf.feature = dma;          /* Use PIO/DMA */
534         cmd->tf.lbam    = bcount & 0xff;
535         cmd->tf.lbah    = (bcount >> 8) & 0xff;
536 }
537
538 static u8 ide_read_ireason(ide_drive_t *drive)
539 {
540         struct ide_taskfile tf;
541
542         drive->hwif->tp_ops->tf_read(drive, &tf, IDE_VALID_NSECT);
543
544         return tf.nsect & 3;
545 }
546
547 static u8 ide_wait_ireason(ide_drive_t *drive, u8 ireason)
548 {
549         int retries = 100;
550
551         while (retries-- && ((ireason & ATAPI_COD) == 0 ||
552                 (ireason & ATAPI_IO))) {
553                 printk(KERN_ERR PFX "%s: (IO,CoD != (0,1) while issuing "
554                                 "a packet command, retrying\n", drive->name);
555                 udelay(100);
556                 ireason = ide_read_ireason(drive);
557                 if (retries == 0) {
558                         printk(KERN_ERR PFX "%s: (IO,CoD != (0,1) while issuing"
559                                         " a packet command, ignoring\n",
560                                         drive->name);
561                         ireason |= ATAPI_COD;
562                         ireason &= ~ATAPI_IO;
563                 }
564         }
565
566         return ireason;
567 }
568
569 static int ide_delayed_transfer_pc(ide_drive_t *drive)
570 {
571         /* Send the actual packet */
572         drive->hwif->tp_ops->output_data(drive, NULL, drive->pc->c, 12);
573
574         /* Timeout for the packet command */
575         return WAIT_FLOPPY_CMD;
576 }
577
578 static ide_startstop_t ide_transfer_pc(ide_drive_t *drive)
579 {
580         struct ide_atapi_pc *uninitialized_var(pc);
581         ide_hwif_t *hwif = drive->hwif;
582         struct request *rq = hwif->rq;
583         ide_expiry_t *expiry;
584         unsigned int timeout;
585         int cmd_len;
586         ide_startstop_t startstop;
587         u8 ireason;
588
589         if (ide_wait_stat(&startstop, drive, ATA_DRQ, ATA_BUSY, WAIT_READY)) {
590                 printk(KERN_ERR PFX "%s: Strange, packet command initiated yet "
591                                 "DRQ isn't asserted\n", drive->name);
592                 return startstop;
593         }
594
595         if (drive->atapi_flags & IDE_AFLAG_DRQ_INTERRUPT) {
596                 if (drive->dma)
597                         drive->waiting_for_dma = 1;
598         }
599
600         if (dev_is_idecd(drive)) {
601                 /* ATAPI commands get padded out to 12 bytes minimum */
602                 cmd_len = COMMAND_SIZE(rq->cmd[0]);
603                 if (cmd_len < ATAPI_MIN_CDB_BYTES)
604                         cmd_len = ATAPI_MIN_CDB_BYTES;
605
606                 timeout = rq->timeout;
607                 expiry  = ide_cd_expiry;
608         } else {
609                 pc = drive->pc;
610
611                 cmd_len = ATAPI_MIN_CDB_BYTES;
612
613                 /*
614                  * If necessary schedule the packet transfer to occur 'timeout'
615                  * miliseconds later in ide_delayed_transfer_pc() after the
616                  * device says it's ready for a packet.
617                  */
618                 if (drive->atapi_flags & IDE_AFLAG_ZIP_DRIVE) {
619                         timeout = drive->pc_delay;
620                         expiry = &ide_delayed_transfer_pc;
621                 } else {
622                         timeout = (drive->media == ide_floppy) ? WAIT_FLOPPY_CMD
623                                                                : WAIT_TAPE_CMD;
624                         expiry = NULL;
625                 }
626
627                 ireason = ide_read_ireason(drive);
628                 if (drive->media == ide_tape)
629                         ireason = ide_wait_ireason(drive, ireason);
630
631                 if ((ireason & ATAPI_COD) == 0 || (ireason & ATAPI_IO)) {
632                         printk(KERN_ERR PFX "%s: (IO,CoD) != (0,1) while "
633                                 "issuing a packet command\n", drive->name);
634
635                         return ide_do_reset(drive);
636                 }
637         }
638
639         hwif->expiry = expiry;
640
641         /* Set the interrupt routine */
642         ide_set_handler(drive,
643                         (dev_is_idecd(drive) ? drive->irq_handler
644                                              : ide_pc_intr),
645                         timeout);
646
647         /* Send the actual packet */
648         if ((drive->atapi_flags & IDE_AFLAG_ZIP_DRIVE) == 0)
649                 hwif->tp_ops->output_data(drive, NULL, rq->cmd, cmd_len);
650
651         /* Begin DMA, if necessary */
652         if (dev_is_idecd(drive)) {
653                 if (drive->dma)
654                         hwif->dma_ops->dma_start(drive);
655         } else {
656                 if (pc->flags & PC_FLAG_DMA_OK) {
657                         pc->flags |= PC_FLAG_DMA_IN_PROGRESS;
658                         hwif->dma_ops->dma_start(drive);
659                 }
660         }
661
662         return ide_started;
663 }
664
665 ide_startstop_t ide_issue_pc(ide_drive_t *drive, struct ide_cmd *cmd)
666 {
667         struct ide_atapi_pc *pc;
668         ide_hwif_t *hwif = drive->hwif;
669         ide_expiry_t *expiry = NULL;
670         struct request *rq = hwif->rq;
671         unsigned int timeout, bytes;
672         u16 bcount;
673         u8 valid_tf;
674         u8 drq_int = !!(drive->atapi_flags & IDE_AFLAG_DRQ_INTERRUPT);
675
676         if (dev_is_idecd(drive)) {
677                 valid_tf = IDE_VALID_NSECT | IDE_VALID_LBAL;
678                 bcount = ide_cd_get_xferlen(rq);
679                 expiry = ide_cd_expiry;
680                 timeout = ATAPI_WAIT_PC;
681
682                 if (drive->dma)
683                         drive->dma = !ide_dma_prepare(drive, cmd);
684         } else {
685                 pc = drive->pc;
686
687                 valid_tf = IDE_VALID_DEVICE;
688                 bytes = blk_rq_bytes(rq);
689                 bcount = ((drive->media == ide_tape) ? bytes
690                                                      : min_t(unsigned int,
691                                                              bytes, 63 * 1024));
692
693                 /* We haven't transferred any data yet */
694                 rq->resid_len = bcount;
695
696                 if (pc->flags & PC_FLAG_DMA_ERROR) {
697                         pc->flags &= ~PC_FLAG_DMA_ERROR;
698                         ide_dma_off(drive);
699                 }
700
701                 if (pc->flags & PC_FLAG_DMA_OK)
702                         drive->dma = !ide_dma_prepare(drive, cmd);
703
704                 if (!drive->dma)
705                         pc->flags &= ~PC_FLAG_DMA_OK;
706
707                 timeout = (drive->media == ide_floppy) ? WAIT_FLOPPY_CMD
708                                                        : WAIT_TAPE_CMD;
709         }
710
711         ide_init_packet_cmd(cmd, valid_tf, bcount, drive->dma);
712
713         (void)do_rw_taskfile(drive, cmd);
714
715         if (drq_int) {
716                 if (drive->dma)
717                         drive->waiting_for_dma = 0;
718                 hwif->expiry = expiry;
719         }
720
721         ide_execute_command(drive, cmd, ide_transfer_pc, timeout);
722
723         return drq_int ? ide_started : ide_transfer_pc(drive);
724 }
725 EXPORT_SYMBOL_GPL(ide_issue_pc);