f9daffd7d0e315270d9f5b7766c627ef60bdb103
[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 #include <linux/gfp.h>
11
12 #include <scsi/scsi.h>
13
14 #define DRV_NAME "ide-atapi"
15 #define PFX DRV_NAME ": "
16
17 #ifdef DEBUG
18 #define debug_log(fmt, args...) \
19         printk(KERN_INFO "ide: " fmt, ## args)
20 #else
21 #define debug_log(fmt, args...) do {} while (0)
22 #endif
23
24 #define ATAPI_MIN_CDB_BYTES     12
25
26 static inline int dev_is_idecd(ide_drive_t *drive)
27 {
28         return drive->media == ide_cdrom || drive->media == ide_optical;
29 }
30
31 /*
32  * Check whether we can support a device,
33  * based on the ATAPI IDENTIFY command results.
34  */
35 int ide_check_atapi_device(ide_drive_t *drive, const char *s)
36 {
37         u16 *id = drive->id;
38         u8 gcw[2], protocol, device_type, removable, drq_type, packet_size;
39
40         *((u16 *)&gcw) = id[ATA_ID_CONFIG];
41
42         protocol    = (gcw[1] & 0xC0) >> 6;
43         device_type =  gcw[1] & 0x1F;
44         removable   = (gcw[0] & 0x80) >> 7;
45         drq_type    = (gcw[0] & 0x60) >> 5;
46         packet_size =  gcw[0] & 0x03;
47
48 #ifdef CONFIG_PPC
49         /* kludge for Apple PowerBook internal zip */
50         if (drive->media == ide_floppy && device_type == 5 &&
51             !strstr((char *)&id[ATA_ID_PROD], "CD-ROM") &&
52             strstr((char *)&id[ATA_ID_PROD], "ZIP"))
53                 device_type = 0;
54 #endif
55
56         if (protocol != 2)
57                 printk(KERN_ERR "%s: %s: protocol (0x%02x) is not ATAPI\n",
58                         s, drive->name, protocol);
59         else if ((drive->media == ide_floppy && device_type != 0) ||
60                  (drive->media == ide_tape && device_type != 1))
61                 printk(KERN_ERR "%s: %s: invalid device type (0x%02x)\n",
62                         s, drive->name, device_type);
63         else if (removable == 0)
64                 printk(KERN_ERR "%s: %s: the removable flag is not set\n",
65                         s, drive->name);
66         else if (drive->media == ide_floppy && drq_type == 3)
67                 printk(KERN_ERR "%s: %s: sorry, DRQ type (0x%02x) not "
68                         "supported\n", s, drive->name, drq_type);
69         else if (packet_size != 0)
70                 printk(KERN_ERR "%s: %s: packet size (0x%02x) is not 12 "
71                         "bytes\n", s, drive->name, packet_size);
72         else
73                 return 1;
74         return 0;
75 }
76 EXPORT_SYMBOL_GPL(ide_check_atapi_device);
77
78 void ide_init_pc(struct ide_atapi_pc *pc)
79 {
80         memset(pc, 0, sizeof(*pc));
81 }
82 EXPORT_SYMBOL_GPL(ide_init_pc);
83
84 /*
85  * Add a special packet command request to the tail of the request queue,
86  * and wait for it to be serviced.
87  */
88 int ide_queue_pc_tail(ide_drive_t *drive, struct gendisk *disk,
89                       struct ide_atapi_pc *pc, void *buf, unsigned int bufflen)
90 {
91         struct request *rq;
92         int error;
93
94         rq = blk_get_request(drive->queue, READ, __GFP_WAIT);
95         rq->cmd_type = REQ_TYPE_SPECIAL;
96         rq->special = (char *)pc;
97
98         if (buf && bufflen) {
99                 error = blk_rq_map_kern(drive->queue, rq, buf, bufflen,
100                                         GFP_NOIO);
101                 if (error)
102                         goto put_req;
103         }
104
105         memcpy(rq->cmd, pc->c, 12);
106         if (drive->media == ide_tape)
107                 rq->cmd[13] = REQ_IDETAPE_PC1;
108         error = blk_execute_rq(drive->queue, disk, rq, 0);
109 put_req:
110         blk_put_request(rq);
111         return error;
112 }
113 EXPORT_SYMBOL_GPL(ide_queue_pc_tail);
114
115 int ide_do_test_unit_ready(ide_drive_t *drive, struct gendisk *disk)
116 {
117         struct ide_atapi_pc pc;
118
119         ide_init_pc(&pc);
120         pc.c[0] = TEST_UNIT_READY;
121
122         return ide_queue_pc_tail(drive, disk, &pc, NULL, 0);
123 }
124 EXPORT_SYMBOL_GPL(ide_do_test_unit_ready);
125
126 int ide_do_start_stop(ide_drive_t *drive, struct gendisk *disk, int start)
127 {
128         struct ide_atapi_pc pc;
129
130         ide_init_pc(&pc);
131         pc.c[0] = START_STOP;
132         pc.c[4] = start;
133
134         if (drive->media == ide_tape)
135                 pc.flags |= PC_FLAG_WAIT_FOR_DSC;
136
137         return ide_queue_pc_tail(drive, disk, &pc, NULL, 0);
138 }
139 EXPORT_SYMBOL_GPL(ide_do_start_stop);
140
141 int ide_set_media_lock(ide_drive_t *drive, struct gendisk *disk, int on)
142 {
143         struct ide_atapi_pc pc;
144
145         if ((drive->dev_flags & IDE_DFLAG_DOORLOCKING) == 0)
146                 return 0;
147
148         ide_init_pc(&pc);
149         pc.c[0] = ALLOW_MEDIUM_REMOVAL;
150         pc.c[4] = on;
151
152         return ide_queue_pc_tail(drive, disk, &pc, NULL, 0);
153 }
154 EXPORT_SYMBOL_GPL(ide_set_media_lock);
155
156 void ide_create_request_sense_cmd(ide_drive_t *drive, struct ide_atapi_pc *pc)
157 {
158         ide_init_pc(pc);
159         pc->c[0] = REQUEST_SENSE;
160         if (drive->media == ide_floppy) {
161                 pc->c[4] = 255;
162                 pc->req_xfer = 18;
163         } else {
164                 pc->c[4] = 20;
165                 pc->req_xfer = 20;
166         }
167 }
168 EXPORT_SYMBOL_GPL(ide_create_request_sense_cmd);
169
170 void ide_prep_sense(ide_drive_t *drive, struct request *rq)
171 {
172         struct request_sense *sense = &drive->sense_data;
173         struct request *sense_rq = &drive->sense_rq;
174         unsigned int cmd_len, sense_len;
175         int err;
176
177         switch (drive->media) {
178         case ide_floppy:
179                 cmd_len = 255;
180                 sense_len = 18;
181                 break;
182         case ide_tape:
183                 cmd_len = 20;
184                 sense_len = 20;
185                 break;
186         default:
187                 cmd_len = 18;
188                 sense_len = 18;
189         }
190
191         BUG_ON(sense_len > sizeof(*sense));
192
193         if (blk_sense_request(rq) || drive->sense_rq_armed)
194                 return;
195
196         memset(sense, 0, sizeof(*sense));
197
198         blk_rq_init(rq->q, sense_rq);
199
200         err = blk_rq_map_kern(drive->queue, sense_rq, sense, sense_len,
201                               GFP_NOIO);
202         if (unlikely(err)) {
203                 if (printk_ratelimit())
204                         printk(KERN_WARNING PFX "%s: failed to map sense "
205                                             "buffer\n", drive->name);
206                 return;
207         }
208
209         sense_rq->rq_disk = rq->rq_disk;
210         sense_rq->cmd[0] = GPCMD_REQUEST_SENSE;
211         sense_rq->cmd[4] = cmd_len;
212         sense_rq->cmd_type = REQ_TYPE_SENSE;
213         sense_rq->cmd_flags |= REQ_PREEMPT;
214
215         if (drive->media == ide_tape)
216                 sense_rq->cmd[13] = REQ_IDETAPE_PC1;
217
218         drive->sense_rq_armed = true;
219 }
220 EXPORT_SYMBOL_GPL(ide_prep_sense);
221
222 int ide_queue_sense_rq(ide_drive_t *drive, void *special)
223 {
224         /* deferred failure from ide_prep_sense() */
225         if (!drive->sense_rq_armed) {
226                 printk(KERN_WARNING PFX "%s: error queuing a sense request\n",
227                        drive->name);
228                 return -ENOMEM;
229         }
230
231         drive->sense_rq.special = special;
232         drive->sense_rq_armed = false;
233
234         drive->hwif->rq = NULL;
235
236         elv_add_request(drive->queue, &drive->sense_rq,
237                         ELEVATOR_INSERT_FRONT, 0);
238         return 0;
239 }
240 EXPORT_SYMBOL_GPL(ide_queue_sense_rq);
241
242 /*
243  * Called when an error was detected during the last packet command.
244  * We queue a request sense packet command at the head of the request
245  * queue.
246  */
247 void ide_retry_pc(ide_drive_t *drive)
248 {
249         struct request *failed_rq = drive->hwif->rq;
250         struct request *sense_rq = &drive->sense_rq;
251         struct ide_atapi_pc *pc = &drive->request_sense_pc;
252
253         (void)ide_read_error(drive);
254
255         /* init pc from sense_rq */
256         ide_init_pc(pc);
257         memcpy(pc->c, sense_rq->cmd, 12);
258
259         if (drive->media == ide_tape)
260                 drive->atapi_flags |= IDE_AFLAG_IGNORE_DSC;
261
262         /*
263          * Push back the failed request and put request sense on top
264          * of it.  The failed command will be retried after sense data
265          * is acquired.
266          */
267         drive->hwif->rq = NULL;
268         ide_requeue_and_plug(drive, failed_rq);
269         if (ide_queue_sense_rq(drive, pc)) {
270                 blk_start_request(failed_rq);
271                 ide_complete_rq(drive, -EIO, blk_rq_bytes(failed_rq));
272         }
273 }
274 EXPORT_SYMBOL_GPL(ide_retry_pc);
275
276 int ide_cd_expiry(ide_drive_t *drive)
277 {
278         struct request *rq = drive->hwif->rq;
279         unsigned long wait = 0;
280
281         debug_log("%s: rq->cmd[0]: 0x%x\n", __func__, rq->cmd[0]);
282
283         /*
284          * Some commands are *slow* and normally take a long time to complete.
285          * Usually we can use the ATAPI "disconnect" to bypass this, but not all
286          * commands/drives support that. Let ide_timer_expiry keep polling us
287          * for these.
288          */
289         switch (rq->cmd[0]) {
290         case GPCMD_BLANK:
291         case GPCMD_FORMAT_UNIT:
292         case GPCMD_RESERVE_RZONE_TRACK:
293         case GPCMD_CLOSE_TRACK:
294         case GPCMD_FLUSH_CACHE:
295                 wait = ATAPI_WAIT_PC;
296                 break;
297         default:
298                 if (!(rq->cmd_flags & REQ_QUIET))
299                         printk(KERN_INFO PFX "cmd 0x%x timed out\n",
300                                          rq->cmd[0]);
301                 wait = 0;
302                 break;
303         }
304         return wait;
305 }
306 EXPORT_SYMBOL_GPL(ide_cd_expiry);
307
308 int ide_cd_get_xferlen(struct request *rq)
309 {
310         if (blk_fs_request(rq))
311                 return 32768;
312         else if (blk_sense_request(rq) || blk_pc_request(rq) ||
313                          rq->cmd_type == REQ_TYPE_ATA_PC)
314                 return blk_rq_bytes(rq);
315         else
316                 return 0;
317 }
318 EXPORT_SYMBOL_GPL(ide_cd_get_xferlen);
319
320 void ide_read_bcount_and_ireason(ide_drive_t *drive, u16 *bcount, u8 *ireason)
321 {
322         struct ide_taskfile tf;
323
324         drive->hwif->tp_ops->tf_read(drive, &tf, IDE_VALID_NSECT |
325                                      IDE_VALID_LBAM | IDE_VALID_LBAH);
326
327         *bcount = (tf.lbah << 8) | tf.lbam;
328         *ireason = tf.nsect & 3;
329 }
330 EXPORT_SYMBOL_GPL(ide_read_bcount_and_ireason);
331
332 /*
333  * Check the contents of the interrupt reason register and attempt to recover if
334  * there are problems.
335  *
336  * Returns:
337  * - 0 if everything's ok
338  * - 1 if the request has to be terminated.
339  */
340 int ide_check_ireason(ide_drive_t *drive, struct request *rq, int len,
341                       int ireason, int rw)
342 {
343         ide_hwif_t *hwif = drive->hwif;
344
345         debug_log("ireason: 0x%x, rw: 0x%x\n", ireason, rw);
346
347         if (ireason == (!rw << 1))
348                 return 0;
349         else if (ireason == (rw << 1)) {
350                 printk(KERN_ERR PFX "%s: %s: wrong transfer direction!\n",
351                                 drive->name, __func__);
352
353                 if (dev_is_idecd(drive))
354                         ide_pad_transfer(drive, rw, len);
355         } else if (!rw && ireason == ATAPI_COD) {
356                 if (dev_is_idecd(drive)) {
357                         /*
358                          * Some drives (ASUS) seem to tell us that status info
359                          * is available.  Just get it and ignore.
360                          */
361                         (void)hwif->tp_ops->read_status(hwif);
362                         return 0;
363                 }
364         } else {
365                 if (ireason & ATAPI_COD)
366                         printk(KERN_ERR PFX "%s: CoD != 0 in %s\n", drive->name,
367                                         __func__);
368
369                 /* drive wants a command packet, or invalid ireason... */
370                 printk(KERN_ERR PFX "%s: %s: bad interrupt reason 0x%02x\n",
371                                 drive->name, __func__, ireason);
372         }
373
374         if (dev_is_idecd(drive) && rq->cmd_type == REQ_TYPE_ATA_PC)
375                 rq->cmd_flags |= REQ_FAILED;
376
377         return 1;
378 }
379 EXPORT_SYMBOL_GPL(ide_check_ireason);
380
381 /*
382  * This is the usual interrupt handler which will be called during a packet
383  * command.  We will transfer some of the data (as requested by the drive)
384  * and will re-point interrupt handler to us.
385  */
386 static ide_startstop_t ide_pc_intr(ide_drive_t *drive)
387 {
388         struct ide_atapi_pc *pc = drive->pc;
389         ide_hwif_t *hwif = drive->hwif;
390         struct ide_cmd *cmd = &hwif->cmd;
391         struct request *rq = hwif->rq;
392         const struct ide_tp_ops *tp_ops = hwif->tp_ops;
393         unsigned int timeout, done;
394         u16 bcount;
395         u8 stat, ireason, dsc = 0;
396         u8 write = !!(pc->flags & PC_FLAG_WRITING);
397
398         debug_log("Enter %s - interrupt handler\n", __func__);
399
400         timeout = (drive->media == ide_floppy) ? WAIT_FLOPPY_CMD
401                                                : WAIT_TAPE_CMD;
402
403         /* Clear the interrupt */
404         stat = tp_ops->read_status(hwif);
405
406         if (pc->flags & PC_FLAG_DMA_IN_PROGRESS) {
407                 int rc;
408
409                 drive->waiting_for_dma = 0;
410                 rc = hwif->dma_ops->dma_end(drive);
411                 ide_dma_unmap_sg(drive, cmd);
412
413                 if (rc || (drive->media == ide_tape && (stat & ATA_ERR))) {
414                         if (drive->media == ide_floppy)
415                                 printk(KERN_ERR PFX "%s: DMA %s error\n",
416                                         drive->name, rq_data_dir(pc->rq)
417                                                      ? "write" : "read");
418                         pc->flags |= PC_FLAG_DMA_ERROR;
419                 } else
420                         rq->resid_len = 0;
421                 debug_log("%s: DMA finished\n", drive->name);
422         }
423
424         /* No more interrupts */
425         if ((stat & ATA_DRQ) == 0) {
426                 int uptodate, error;
427
428                 debug_log("Packet command completed, %d bytes transferred\n",
429                           blk_rq_bytes(rq));
430
431                 pc->flags &= ~PC_FLAG_DMA_IN_PROGRESS;
432
433                 local_irq_enable_in_hardirq();
434
435                 if (drive->media == ide_tape &&
436                     (stat & ATA_ERR) && rq->cmd[0] == REQUEST_SENSE)
437                         stat &= ~ATA_ERR;
438
439                 if ((stat & ATA_ERR) || (pc->flags & PC_FLAG_DMA_ERROR)) {
440                         /* Error detected */
441                         debug_log("%s: I/O error\n", drive->name);
442
443                         if (drive->media != ide_tape)
444                                 pc->rq->errors++;
445
446                         if (rq->cmd[0] == REQUEST_SENSE) {
447                                 printk(KERN_ERR PFX "%s: I/O error in request "
448                                                 "sense command\n", drive->name);
449                                 return ide_do_reset(drive);
450                         }
451
452                         debug_log("[cmd %x]: check condition\n", rq->cmd[0]);
453
454                         /* Retry operation */
455                         ide_retry_pc(drive);
456
457                         /* queued, but not started */
458                         return ide_stopped;
459                 }
460                 pc->error = 0;
461
462                 if ((pc->flags & PC_FLAG_WAIT_FOR_DSC) && (stat & ATA_DSC) == 0)
463                         dsc = 1;
464
465                 /*
466                  * ->pc_callback() might change rq->data_len for
467                  * residual count, cache total length.
468                  */
469                 done = blk_rq_bytes(rq);
470
471                 /* Command finished - Call the callback function */
472                 uptodate = drive->pc_callback(drive, dsc);
473
474                 if (uptodate == 0)
475                         drive->failed_pc = NULL;
476
477                 if (blk_special_request(rq)) {
478                         rq->errors = 0;
479                         error = 0;
480                 } else {
481
482                         if (blk_fs_request(rq) == 0 && uptodate <= 0) {
483                                 if (rq->errors == 0)
484                                         rq->errors = -EIO;
485                         }
486
487                         error = uptodate ? 0 : -EIO;
488                 }
489
490                 ide_complete_rq(drive, error, blk_rq_bytes(rq));
491                 return ide_stopped;
492         }
493
494         if (pc->flags & PC_FLAG_DMA_IN_PROGRESS) {
495                 pc->flags &= ~PC_FLAG_DMA_IN_PROGRESS;
496                 printk(KERN_ERR PFX "%s: The device wants to issue more "
497                                 "interrupts in DMA mode\n", drive->name);
498                 ide_dma_off(drive);
499                 return ide_do_reset(drive);
500         }
501
502         /* Get the number of bytes to transfer on this interrupt. */
503         ide_read_bcount_and_ireason(drive, &bcount, &ireason);
504
505         if (ide_check_ireason(drive, rq, bcount, ireason, write))
506                 return ide_do_reset(drive);
507
508         done = min_t(unsigned int, bcount, cmd->nleft);
509         ide_pio_bytes(drive, cmd, write, done);
510
511         /* Update transferred byte count */
512         rq->resid_len -= done;
513
514         bcount -= done;
515
516         if (bcount)
517                 ide_pad_transfer(drive, write, bcount);
518
519         debug_log("[cmd %x] transferred %d bytes, padded %d bytes, resid: %u\n",
520                   rq->cmd[0], done, bcount, rq->resid_len);
521
522         /* And set the interrupt handler again */
523         ide_set_handler(drive, ide_pc_intr, timeout);
524         return ide_started;
525 }
526
527 static void ide_init_packet_cmd(struct ide_cmd *cmd, u8 valid_tf,
528                                 u16 bcount, u8 dma)
529 {
530         cmd->protocol = dma ? ATAPI_PROT_DMA : ATAPI_PROT_PIO;
531         cmd->valid.out.tf = IDE_VALID_LBAH | IDE_VALID_LBAM |
532                             IDE_VALID_FEATURE | valid_tf;
533         cmd->tf.command = ATA_CMD_PACKET;
534         cmd->tf.feature = dma;          /* Use PIO/DMA */
535         cmd->tf.lbam    = bcount & 0xff;
536         cmd->tf.lbah    = (bcount >> 8) & 0xff;
537 }
538
539 static u8 ide_read_ireason(ide_drive_t *drive)
540 {
541         struct ide_taskfile tf;
542
543         drive->hwif->tp_ops->tf_read(drive, &tf, IDE_VALID_NSECT);
544
545         return tf.nsect & 3;
546 }
547
548 static u8 ide_wait_ireason(ide_drive_t *drive, u8 ireason)
549 {
550         int retries = 100;
551
552         while (retries-- && ((ireason & ATAPI_COD) == 0 ||
553                 (ireason & ATAPI_IO))) {
554                 printk(KERN_ERR PFX "%s: (IO,CoD != (0,1) while issuing "
555                                 "a packet command, retrying\n", drive->name);
556                 udelay(100);
557                 ireason = ide_read_ireason(drive);
558                 if (retries == 0) {
559                         printk(KERN_ERR PFX "%s: (IO,CoD != (0,1) while issuing"
560                                         " a packet command, ignoring\n",
561                                         drive->name);
562                         ireason |= ATAPI_COD;
563                         ireason &= ~ATAPI_IO;
564                 }
565         }
566
567         return ireason;
568 }
569
570 static int ide_delayed_transfer_pc(ide_drive_t *drive)
571 {
572         /* Send the actual packet */
573         drive->hwif->tp_ops->output_data(drive, NULL, drive->pc->c, 12);
574
575         /* Timeout for the packet command */
576         return WAIT_FLOPPY_CMD;
577 }
578
579 static ide_startstop_t ide_transfer_pc(ide_drive_t *drive)
580 {
581         struct ide_atapi_pc *uninitialized_var(pc);
582         ide_hwif_t *hwif = drive->hwif;
583         struct request *rq = hwif->rq;
584         ide_expiry_t *expiry;
585         unsigned int timeout;
586         int cmd_len;
587         ide_startstop_t startstop;
588         u8 ireason;
589
590         if (ide_wait_stat(&startstop, drive, ATA_DRQ, ATA_BUSY, WAIT_READY)) {
591                 printk(KERN_ERR PFX "%s: Strange, packet command initiated yet "
592                                 "DRQ isn't asserted\n", drive->name);
593                 return startstop;
594         }
595
596         if (drive->atapi_flags & IDE_AFLAG_DRQ_INTERRUPT) {
597                 if (drive->dma)
598                         drive->waiting_for_dma = 1;
599         }
600
601         if (dev_is_idecd(drive)) {
602                 /* ATAPI commands get padded out to 12 bytes minimum */
603                 cmd_len = COMMAND_SIZE(rq->cmd[0]);
604                 if (cmd_len < ATAPI_MIN_CDB_BYTES)
605                         cmd_len = ATAPI_MIN_CDB_BYTES;
606
607                 timeout = rq->timeout;
608                 expiry  = ide_cd_expiry;
609         } else {
610                 pc = drive->pc;
611
612                 cmd_len = ATAPI_MIN_CDB_BYTES;
613
614                 /*
615                  * If necessary schedule the packet transfer to occur 'timeout'
616                  * milliseconds later in ide_delayed_transfer_pc() after the
617                  * device says it's ready for a packet.
618                  */
619                 if (drive->atapi_flags & IDE_AFLAG_ZIP_DRIVE) {
620                         timeout = drive->pc_delay;
621                         expiry = &ide_delayed_transfer_pc;
622                 } else {
623                         timeout = (drive->media == ide_floppy) ? WAIT_FLOPPY_CMD
624                                                                : WAIT_TAPE_CMD;
625                         expiry = NULL;
626                 }
627
628                 ireason = ide_read_ireason(drive);
629                 if (drive->media == ide_tape)
630                         ireason = ide_wait_ireason(drive, ireason);
631
632                 if ((ireason & ATAPI_COD) == 0 || (ireason & ATAPI_IO)) {
633                         printk(KERN_ERR PFX "%s: (IO,CoD) != (0,1) while "
634                                 "issuing a packet command\n", drive->name);
635
636                         return ide_do_reset(drive);
637                 }
638         }
639
640         hwif->expiry = expiry;
641
642         /* Set the interrupt routine */
643         ide_set_handler(drive,
644                         (dev_is_idecd(drive) ? drive->irq_handler
645                                              : ide_pc_intr),
646                         timeout);
647
648         /* Send the actual packet */
649         if ((drive->atapi_flags & IDE_AFLAG_ZIP_DRIVE) == 0)
650                 hwif->tp_ops->output_data(drive, NULL, rq->cmd, cmd_len);
651
652         /* Begin DMA, if necessary */
653         if (dev_is_idecd(drive)) {
654                 if (drive->dma)
655                         hwif->dma_ops->dma_start(drive);
656         } else {
657                 if (pc->flags & PC_FLAG_DMA_OK) {
658                         pc->flags |= PC_FLAG_DMA_IN_PROGRESS;
659                         hwif->dma_ops->dma_start(drive);
660                 }
661         }
662
663         return ide_started;
664 }
665
666 ide_startstop_t ide_issue_pc(ide_drive_t *drive, struct ide_cmd *cmd)
667 {
668         struct ide_atapi_pc *pc;
669         ide_hwif_t *hwif = drive->hwif;
670         ide_expiry_t *expiry = NULL;
671         struct request *rq = hwif->rq;
672         unsigned int timeout, bytes;
673         u16 bcount;
674         u8 valid_tf;
675         u8 drq_int = !!(drive->atapi_flags & IDE_AFLAG_DRQ_INTERRUPT);
676
677         if (dev_is_idecd(drive)) {
678                 valid_tf = IDE_VALID_NSECT | IDE_VALID_LBAL;
679                 bcount = ide_cd_get_xferlen(rq);
680                 expiry = ide_cd_expiry;
681                 timeout = ATAPI_WAIT_PC;
682
683                 if (drive->dma)
684                         drive->dma = !ide_dma_prepare(drive, cmd);
685         } else {
686                 pc = drive->pc;
687
688                 valid_tf = IDE_VALID_DEVICE;
689                 bytes = blk_rq_bytes(rq);
690                 bcount = ((drive->media == ide_tape) ? bytes
691                                                      : min_t(unsigned int,
692                                                              bytes, 63 * 1024));
693
694                 /* We haven't transferred any data yet */
695                 rq->resid_len = bcount;
696
697                 if (pc->flags & PC_FLAG_DMA_ERROR) {
698                         pc->flags &= ~PC_FLAG_DMA_ERROR;
699                         ide_dma_off(drive);
700                 }
701
702                 if (pc->flags & PC_FLAG_DMA_OK)
703                         drive->dma = !ide_dma_prepare(drive, cmd);
704
705                 if (!drive->dma)
706                         pc->flags &= ~PC_FLAG_DMA_OK;
707
708                 timeout = (drive->media == ide_floppy) ? WAIT_FLOPPY_CMD
709                                                        : WAIT_TAPE_CMD;
710         }
711
712         ide_init_packet_cmd(cmd, valid_tf, bcount, drive->dma);
713
714         (void)do_rw_taskfile(drive, cmd);
715
716         if (drq_int) {
717                 if (drive->dma)
718                         drive->waiting_for_dma = 0;
719                 hwif->expiry = expiry;
720         }
721
722         ide_execute_command(drive, cmd, ide_transfer_pc, timeout);
723
724         return drq_int ? ide_started : ide_transfer_pc(drive);
725 }
726 EXPORT_SYMBOL_GPL(ide_issue_pc);