aboutsummaryrefslogtreecommitdiff
path: root/drivers/ide/ide-atapi.c
blob: e88a2cf177110f37fdd6bfc6d1801184ec2b94f4 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
/*
 * ATAPI support.
 */

#include <linux/kernel.h>
#include <linux/cdrom.h>
#include <linux/delay.h>
#include <linux/ide.h>
#include <linux/scatterlist.h>
#include <linux/gfp.h>

#include <scsi/scsi.h>

#define DRV_NAME "ide-atapi"
#define PFX DRV_NAME ": "

#ifdef DEBUG
#define debug_log(fmt, args...) \
	printk(KERN_INFO "ide: " fmt, ## args)
#else
#define debug_log(fmt, args...) do {} while (0)
#endif

#define ATAPI_MIN_CDB_BYTES	12

static inline int dev_is_idecd(ide_drive_t *drive)
{
	return drive->media == ide_cdrom || drive->media == ide_optical;
}

/*
 * Check whether we can support a device,
 * based on the ATAPI IDENTIFY command results.
 */
int ide_check_atapi_device(ide_drive_t *drive, const char *s)
{
	u16 *id = drive->id;
	u8 gcw[2], protocol, device_type, removable, drq_type, packet_size;

	*((u16 *)&gcw) = id[ATA_ID_CONFIG];

	protocol    = (gcw[1] & 0xC0) >> 6;
	device_type =  gcw[1] & 0x1F;
	removable   = (gcw[0] & 0x80) >> 7;
	drq_type    = (gcw[0] & 0x60) >> 5;
	packet_size =  gcw[0] & 0x03;

#ifdef CONFIG_PPC
	/* kludge for Apple PowerBook internal zip */
	if (drive->media == ide_floppy && device_type == 5 &&
	    !strstr((char *)&id[ATA_ID_PROD], "CD-ROM") &&
	    strstr((char *)&id[ATA_ID_PROD], "ZIP"))
		device_type = 0;
#endif

	if (protocol != 2)
		printk(KERN_ERR "%s: %s: protocol (0x%02x) is not ATAPI\n",
			s, drive->name, protocol);
	else if ((drive->media == ide_floppy && device_type != 0) ||
		 (drive->media == ide_tape && device_type != 1))
		printk(KERN_ERR "%s: %s: invalid device type (0x%02x)\n",
			s, drive->name, device_type);
	else if (removable == 0)
		printk(KERN_ERR "%s: %s: the removable flag is not set\n",
			s, drive->name);
	else if (drive->media == ide_floppy && drq_type == 3)
		printk(KERN_ERR "%s: %s: sorry, DRQ type (0x%02x) not "
			"supported\n", s, drive->name, drq_type);
	else if (packet_size != 0)
		printk(KERN_ERR "%s: %s: packet size (0x%02x) is not 12 "
			"bytes\n", s, drive->name, packet_size);
	else
		return 1;
	return 0;
}
EXPORT_SYMBOL_GPL(ide_check_atapi_device);

void ide_init_pc(struct ide_atapi_pc *pc)
{
	memset(pc, 0, sizeof(*pc));
}
EXPORT_SYMBOL_GPL(ide_init_pc);

/*
 * Add a special packet command request to the tail of the request queue,
 * and wait for it to be serviced.
 */
int ide_queue_pc_tail(ide_drive_t *drive, struct gendisk *disk,
		      struct ide_atapi_pc *pc, void *buf, unsigned int bufflen)
{
	struct request *rq;
	int error;

	rq = blk_get_request(drive->queue, READ, __GFP_WAIT);
	rq->cmd_type = REQ_TYPE_SPECIAL;
	rq->special = (char *)pc;

	if (buf && bufflen) {
		error = blk_rq_map_kern(drive->queue, rq, buf, bufflen,
					GFP_NOIO);
		if (error)
			goto put_req;
	}

	memcpy(rq->cmd, pc->c, 12);
	if (drive->media == ide_tape)
		rq->cmd[13] = REQ_IDETAPE_PC1;
	error = blk_execute_rq(drive->queue, disk, rq, 0);
put_req:
	blk_put_request(rq);
	return error;
}
EXPORT_SYMBOL_GPL(ide_queue_pc_tail);

int ide_do_test_unit_ready(ide_drive_t *drive, struct gendisk *disk)
{
	struct ide_atapi_pc pc;

	ide_init_pc(&pc);
	pc.c[0] = TEST_UNIT_READY;

	return ide_queue_pc_tail(drive, disk, &pc, NULL, 0);
}
EXPORT_SYMBOL_GPL(ide_do_test_unit_ready);

int ide_do_start_stop(ide_drive_t *drive, struct gendisk *disk, int start)
{
	struct ide_atapi_pc pc;

	ide_init_pc(&pc);
	pc.c[0] = START_STOP;
	pc.c[4] = start;

	if (drive->media == ide_tape)
		pc.flags |= PC_FLAG_WAIT_FOR_DSC;

	return ide_queue_pc_tail(drive, disk, &pc, NULL, 0);
}
EXPORT_SYMBOL_GPL(ide_do_start_stop);

int ide_set_media_lock(ide_drive_t *drive, struct gendisk *disk, int on)
{
	struct ide_atapi_pc pc;

	if ((drive->dev_flags & IDE_DFLAG_DOORLOCKING) == 0)
		return 0;

	ide_init_pc(&pc);
	pc.c[0] = ALLOW_MEDIUM_REMOVAL;
	pc.c[4] = on;

	return ide_queue_pc_tail(drive, disk, &pc, NULL, 0);
}
EXPORT_SYMBOL_GPL(ide_set_media_lock);

void ide_create_request_sense_cmd(ide_drive_t *drive, struct ide_atapi_pc *pc)
{
	ide_init_pc(pc);
	pc->c[0] = REQUEST_SENSE;
	if (drive->media == ide_floppy) {
		pc->c[4] = 255;
		pc->req_xfer = 18;
	} else {
		pc->c[4] = 20;
		pc->req_xfer = 20;
	}
}
EXPORT_SYMBOL_GPL(ide_create_request_sense_cmd);

void ide_prep_sense(ide_drive_t *drive, struct request *rq)
{
	struct request_sense *sense = &drive->sense_data;
	struct request *sense_rq = &drive->sense_rq;
	unsigned int cmd_len, sense_len;
	int err;

	switch (drive->media) {
	case ide_floppy:
		cmd_len = 255;
		sense_len = 18;
		break;
	case ide_tape:
		cmd_len = 20;
		sense_len = 20;
		break;
	default:
		cmd_len = 18;
		sense_len = 18;
	}

	BUG_ON(sense_len > sizeof(*sense));

	if (rq->cmd_type == REQ_TYPE_SENSE || drive->sense_rq_armed)
		return;

	memset(sense, 0, sizeof(*sense));

	blk_rq_init(rq->q, sense_rq);

	err = blk_rq_map_kern(drive->queue, sense_rq, sense, sense_len,
			      GFP_NOIO);
	if (unlikely(err)) {
		if (printk_ratelimit())
			printk(KERN_WARNING PFX "%s: failed to map sense "
					    "buffer\n", drive->name);
		return;
	}

	sense_rq->rq_disk = rq->rq_disk;
	sense_rq->cmd[0] = GPCMD_REQUEST_SENSE;
	sense_rq->cmd[4] = cmd_len;
	sense_rq->cmd_type = REQ_TYPE_SENSE;
	sense_rq->cmd_flags |= REQ_PREEMPT;

	if (drive->media == ide_tape)
		sense_rq->cmd[13] = REQ_IDETAPE_PC1;

	drive->sense_rq_armed = true;
}
EXPORT_SYMBOL_GPL(ide_prep_sense);

int ide_queue_sense_rq(ide_drive_t *drive, void *special)
{
	/* deferred failure from ide_prep_sense() */
	if (!drive->sense_rq_armed) {
		printk(KERN_WARNING PFX "%s: error queuing a sense request\n",
		       drive->name);
		return -ENOMEM;
	}

	drive->sense_rq.special = special;
	drive->sense_rq_armed = false;

	drive->hwif->rq = NULL;

	elv_add_request(drive->queue, &drive->sense_rq,
			ELEVATOR_INSERT_FRONT, 0);
	return 0;
}
EXPORT_SYMBOL_GPL(ide_queue_sense_rq);

/*
 * Called when an error was detected during the last packet command.
 * We queue a request sense packet command at the head of the request
 * queue.
 */
void ide_retry_pc(ide_drive_t *drive)
{
	struct request *failed_rq = drive->hwif->rq;
	struct request *sense_rq = &drive->sense_rq;
	struct ide_atapi_pc *pc = &drive->request_sense_pc;

	(void)ide_read_error(drive);

	/* init pc from sense_rq */
	ide_init_pc(pc);
	memcpy(pc->c, sense_rq->cmd, 12);

	if (drive->media == ide_tape)
		drive->atapi_flags |= IDE_AFLAG_IGNORE_DSC;

	/*
	 * Push back the failed request and put request sense on top
	 * of it.  The failed command will be retried after sense data
	 * is acquired.
	 */
	drive->hwif->rq = NULL;
	ide_requeue_and_plug(drive, failed_rq);
	if (ide_queue_sense_rq(drive, pc)) {
		blk_start_request(failed_rq);
		ide_complete_rq(drive, -EIO, blk_rq_bytes(failed_rq));
	}
}
EXPORT_SYMBOL_GPL(ide_retry_pc);

int ide_cd_expiry(ide_drive_t *drive)
{
	struct request *rq = drive->hwif->rq;
	unsigned long wait = 0;

	debug_log("%s: rq->cmd[0]: 0x%x\n", __func__, rq->cmd[0]);

	/*
	 * Some commands are *slow* and normally take a long time to complete.
	 * Usually we can use the ATAPI "disconnect" to bypass this, but not all
	 * commands/drives support that. Let ide_timer_expiry keep polling us
	 * for these.
	 */
	switch (rq->cmd[0]) {
	case GPCMD_BLANK:
	case GPCMD_FORMAT_UNIT:
	case GPCMD_RESERVE_RZONE_TRACK:
	case GPCMD_CLOSE_TRACK:
	case GPCMD_FLUSH_CACHE:
		wait = ATAPI_WAIT_PC;
		break;
	default:
		if (!(rq->cmd_flags & REQ_QUIET))
			printk(KERN_INFO PFX "cmd 0x%x timed out\n",
					 rq->cmd[0]);
		wait = 0;
		break;
	}
	return wait;
}
EXPORT_SYMBOL_GPL(ide_cd_expiry);

int ide_cd_get_xferlen(struct request *rq)
{
	switch (rq->cmd_type) {
	case REQ_TYPE_FS:
		return 32768;
	case REQ_TYPE_SENSE:
	case REQ_TYPE_BLOCK_PC:
	case REQ_TYPE_ATA_PC:
		return blk_rq_bytes(rq);
	default:
		return 0;
	}
}
EXPORT_SYMBOL_GPL(ide_cd_get_xferlen);

void ide_read_bcount_and_ireason(ide_drive_t *drive, u16 *bcount, u8 *ireason)
{
	struct ide_taskfile tf;

	drive->hwif->tp_ops->tf_read(drive, &tf, IDE_VALID_NSECT |
				     IDE_VALID_LBAM | IDE_VALID_LBAH);

	*bcount = (tf.lbah << 8) | tf.lbam;
	*ireason = tf.nsect & 3;
}
EXPORT_SYMBOL_GPL(ide_read_bcount_and_ireason);

/*
 * Check the contents of the interrupt reason register and attempt to recover if
 * there are problems.
 *
 * Returns:
 * - 0 if everything's ok
 * - 1 if the request has to be terminated.
 */
int ide_check_ireason(ide_drive_t *drive, struct request *rq, int len,
		      int ireason, int rw)
{
	ide_hwif_t *hwif = drive->hwif;

	debug_log("ireason: 0x%x, rw: 0x%x\n", ireason, rw);

	if (ireason == (!rw << 1))
		return 0;
	else if (ireason == (rw << 1)) {
		printk(KERN_ERR PFX "%s: %s: wrong transfer direction!\n",
				drive->name, __func__);

		if (dev_is_idecd(drive))
			ide_pad_transfer(drive, rw, len);
	} else if (!rw && ireason == ATAPI_COD) {
		if (dev_is_idecd(drive)) {
			/*
			 * Some drives (ASUS) seem to tell us that status info
			 * is available.  Just get it and ignore.
			 */
			(void)hwif->tp_ops->read_status(hwif);
			return 0;
		}
	} else {
		if (ireason & ATAPI_COD)
			printk(KERN_ERR PFX "%s: CoD != 0 in %s\n", drive->name,
					__func__);

		/* drive wants a command packet, or invalid ireason... */
		printk(KERN_ERR PFX "%s: %s: bad interrupt reason 0x%02x\n",
				drive->name, __func__, ireason);
	}

	if (dev_is_idecd(drive) && rq->cmd_type == REQ_TYPE_ATA_PC)
		rq->cmd_flags |= REQ_FAILED;

	return 1;
}
EXPORT_SYMBOL_GPL(ide_check_ireason);

/*
 * This is the usual interrupt handler which will be called during a packet
 * command.  We will transfer some of the data (as requested by the drive)
 * and will re-point interrupt handler to us.
 */
static ide_startstop_t ide_pc_intr(ide_drive_t *drive)
{
	struct ide_atapi_pc *pc = drive->pc;
	ide_hwif_t *hwif = drive->hwif;
	struct ide_cmd *cmd = &hwif->cmd;
	struct request *rq = hwif->rq;
	const struct ide_tp_ops *tp_ops = hwif->tp_ops;
	unsigned int timeout, done;
	u16 bcount;
	u8 stat, ireason, dsc = 0;
	u8 write = !!(pc->flags & PC_FLAG_WRITING);

	debug_log("Enter %s - interrupt handler\n", __func__);

	timeout = (drive->media == ide_floppy) ? WAIT_FLOPPY_CMD
					       : WAIT_TAPE_CMD;

	/* Clear the interrupt */
	stat = tp_ops->read_status(hwif);

	if (pc->flags & PC_FLAG_DMA_IN_PROGRESS) {
		int rc;

		drive->waiting_for_dma = 0;
		rc = hwif->dma_ops->dma_end(drive);
		ide_dma_unmap_sg(drive, cmd);

		if (rc || (drive->media == ide_tape && (stat & ATA_ERR))) {
			if (drive->media == ide_floppy)
				printk(KERN_ERR PFX "%s: DMA %s error\n",
					drive->name, rq_data_dir(pc->rq)
						     ? "write" : "read");
			pc->flags |= PC_FLAG_DMA_ERROR;
		} else
			rq->resid_len = 0;
		debug_log("%s: DMA finished\n", drive->name);
	}

	/* No more interrupts */
	if ((stat & ATA_DRQ) == 0) {
		int uptodate, error;

		debug_log("Packet command completed, %d bytes transferred\n",
			  blk_rq_bytes(rq));

		pc->flags &= ~PC_FLAG_DMA_IN_PROGRESS;

		local_irq_enable_in_hardirq();

		if (drive->media == ide_tape &&
		    (stat & ATA_ERR) && rq->cmd[0] == REQUEST_SENSE)
			stat &= ~ATA_ERR;

		if ((stat & ATA_ERR) || (pc->flags & PC_FLAG_DMA_ERROR)) {
			/* Error detected */
			debug_log("%s: I/O error\n", drive->name);

			if (drive->media != ide_tape)
				pc->rq->errors++;

			if (rq->cmd[0] == REQUEST_SENSE) {
				printk(KERN_ERR PFX "%s: I/O error in request "
						"sense command\n", drive->name);
				return ide_do_reset(drive);
			}

			debug_log("[cmd %x]: check condition\n", rq->cmd[0]);

			/* Retry operation */
			ide_retry_pc(drive);

			/* queued, but not started */
			return ide_stopped;
		}
		pc->error = 0;

		if ((pc->flags & PC_FLAG_WAIT_FOR_DSC) && (stat & ATA_DSC) == 0)
			dsc = 1;

		/*
		 * ->pc_callback() might change rq->data_len for
		 * residual count, cache total length.
		 */
		done = blk_rq_bytes(rq);

		/* Command finished - Call the callback function */
		uptodate = drive->pc_callback(drive, dsc);

		if (uptodate == 0)
			drive->failed_pc = NULL;

		if (rq->cmd_type == REQ_TYPE_SPECIAL) {
			rq->errors = 0;
			error = 0;
		} else {

			if (rq->cmd_type != REQ_TYPE_FS && uptodate <= 0) {
				if (rq->errors == 0)
					rq->errors = -EIO;
			}

			error = uptodate ? 0 : -EIO;
		}

		ide_complete_rq(drive, error, blk_rq_bytes(rq));
		return ide_stopped;
	}

	if (pc->flags & PC_FLAG_DMA_IN_PROGRESS) {
		pc->flags &= ~PC_FLAG_DMA_IN_PROGRESS;
		printk(KERN_ERR PFX "%s: The device wants to issue more "
				"interrupts in DMA mode\n", drive->name);
		ide_dma_off(drive);
		return ide_do_reset(drive);
	}

	/* Get the number of bytes to transfer on this interrupt. */
	ide_read_bcount_and_ireason(drive, &bcount, &ireason);

	if (ide_check_ireason(drive, rq, bcount, ireason, write))
		return ide_do_reset(drive);

	done = min_t(unsigned int, bcount, cmd->nleft);
	ide_pio_bytes(drive, cmd, write, done);

	/* Update transferred byte count */
	rq->resid_len -= done;

	bcount -= done;

	if (bcount)
		ide_pad_transfer(drive, write, bcount);

	debug_log("[cmd %x] transferred %d bytes, padded %d bytes, resid: %u\n",
		  rq->cmd[0], done, bcount, rq->resid_len);

	/* And set the interrupt handler again */
	ide_set_handler(drive, ide_pc_intr, timeout);
	return ide_started;
}

static void ide_init_packet_cmd(struct ide_cmd *cmd, u8 valid_tf,
				u16 bcount, u8 dma)
{
	cmd->protocol = dma ? ATAPI_PROT_DMA : ATAPI_PROT_PIO;
	cmd->valid.out.tf = IDE_VALID_LBAH | IDE_VALID_LBAM |
			    IDE_VALID_FEATURE | valid_tf;
	cmd->tf.command = ATA_CMD_PACKET;
	cmd->tf.feature = dma;		/* Use PIO/DMA */
	cmd->tf.lbam    = bcount & 0xff;
	cmd->tf.lbah    = (bcount >> 8) & 0xff;
}

static u8 ide_read_ireason(ide_drive_t *drive)
{
	struct ide_taskfile tf;

	drive->hwif->tp_ops->tf_read(drive, &tf, IDE_VALID_NSECT);

	return tf.nsect & 3;
}

static u8 ide_wait_ireason(ide_drive_t *drive, u8 ireason)
{
	int retries = 100;

	while (retries-- && ((ireason & ATAPI_COD) == 0 ||
		(ireason & ATAPI_IO))) {
		printk(KERN_ERR PFX "%s: (IO,CoD != (0,1) while issuing "
				"a packet command, retrying\n", drive->name);
		udelay(100);
		ireason = ide_read_ireason(drive);
		if (retries == 0) {
			printk(KERN_ERR PFX "%s: (IO,CoD != (0,1) while issuing"
					" a packet command, ignoring\n",
					drive->name);
			ireason |= ATAPI_COD;
			ireason &= ~ATAPI_IO;
		}
	}

	return ireason;
}

static int ide_delayed_transfer_pc(ide_drive_t *drive)
{
	/* Send the actual packet */
	drive->hwif->tp_ops->output_data(drive, NULL, drive->pc->c, 12);

	/* Timeout for the packet command */
	return WAIT_FLOPPY_CMD;
}

static ide_startstop_t ide_transfer_pc(ide_drive_t *drive)
{
	struct ide_atapi_pc *uninitialized_var(pc);
	ide_hwif_t *hwif = drive->hwif;
	struct request *rq = hwif->rq;
	ide_expiry_t *expiry;
	unsigned int timeout;
	int cmd_len;
	ide_startstop_t startstop;
	u8 ireason;

	if (ide_wait_stat(&startstop, drive, ATA_DRQ, ATA_BUSY, WAIT_READY)) {
		printk(KERN_ERR PFX "%s: Strange, packet command initiated yet "
				"DRQ isn't asserted\n", drive->name);
		return startstop;
	}

	if (drive->atapi_flags & IDE_AFLAG_DRQ_INTERRUPT) {
		if (drive->dma)
			drive->waiting_for_dma = 1;
	}

	if (dev_is_idecd(drive)) {
		/* ATAPI commands get padded out to 12 bytes minimum */
		cmd_len = COMMAND_SIZE(rq->cmd[0]);
		if (cmd_len < ATAPI_MIN_CDB_BYTES)
			cmd_len = ATAPI_MIN_CDB_BYTES;

		timeout = rq->timeout;
		expiry  = ide_cd_expiry;
	} else {
		pc = drive->pc;

		cmd_len = ATAPI_MIN_CDB_BYTES;

		/*
		 * If necessary schedule the packet transfer to occur 'timeout'
		 * milliseconds later in ide_delayed_transfer_pc() after the
		 * device says it's ready for a packet.
		 */
		if (drive->atapi_flags & IDE_AFLAG_ZIP_DRIVE) {
			timeout = drive->pc_delay;
			expiry = &ide_delayed_transfer_pc;
		} else {
			timeout = (drive->media == ide_floppy) ? WAIT_FLOPPY_CMD
							       : WAIT_TAPE_CMD;
			expiry = NULL;
		}

		ireason = ide_read_ireason(drive);
		if (drive->media == ide_tape)
			ireason = ide_wait_ireason(drive, ireason);

		if ((ireason & ATAPI_COD) == 0 || (ireason & ATAPI_IO)) {
			printk(KERN_ERR PFX "%s: (IO,CoD) != (0,1) while "
				"issuing a packet command\n", drive->name);

			return ide_do_reset(drive);
		}
	}

	hwif->expiry = expiry;

	/* Set the interrupt routine */
	ide_set_handler(drive,
			(dev_is_idecd(drive) ? drive->irq_handler
					     : ide_pc_intr),
			timeout);

	/* Send the actual packet */
	if ((drive->atapi_flags & IDE_AFLAG_ZIP_DRIVE) == 0)
		hwif->tp_ops->output_data(drive, NULL, rq->cmd, cmd_len);

	/* Begin DMA, if necessary */
	if (dev_is_idecd(drive)) {
		if (drive->dma)
			hwif->dma_ops->dma_start(drive);
	} else {
		if (pc->flags & PC_FLAG_DMA_OK) {
			pc->flags |= PC_FLAG_DMA_IN_PROGRESS;
			hwif->dma_ops->dma_start(drive);
		}
	}

	return ide_started;
}

ide_startstop_t ide_issue_pc(ide_drive_t *drive, struct ide_cmd *cmd)
{
	struct ide_atapi_pc *pc;
	ide_hwif_t *hwif = drive->hwif;
	ide_expiry_t *expiry = NULL;
	struct request *rq = hwif->rq;
	unsigned int timeout, bytes;
	u16 bcount;
	u8 valid_tf;
	u8 drq_int = !!(drive->atapi_flags & IDE_AFLAG_DRQ_INTERRUPT);

	if (dev_is_idecd(drive)) {
		valid_tf = IDE_VALID_NSECT | IDE_VALID_LBAL;
		bcount = ide_cd_get_xferlen(rq);
		expiry = ide_cd_expiry;
		timeout = ATAPI_WAIT_PC;

		if (drive->dma)
			drive->dma = !ide_dma_prepare(drive, cmd);
	} else {
		pc = drive->pc;

		valid_tf = IDE_VALID_DEVICE;
		bytes = blk_rq_bytes(rq);
		bcount = ((drive->media == ide_tape) ? bytes
						     : min_t(unsigned int,
							     bytes, 63 * 1024));

		/* We haven't transferred any data yet */
		rq->resid_len = bcount;

		if (pc->flags & PC_FLAG_DMA_ERROR) {
			pc->flags &= ~PC_FLAG_DMA_ERROR;
			ide_dma_off(drive);
		}

		if (pc->flags & PC_FLAG_DMA_OK)
			drive->dma = !ide_dma_prepare(drive, cmd);

		if (!drive->dma)
			pc->flags &= ~PC_FLAG_DMA_OK;

		timeout = (drive->media == ide_floppy) ? WAIT_FLOPPY_CMD
						       : WAIT_TAPE_CMD;
	}

	ide_init_packet_cmd(cmd, valid_tf, bcount, drive->dma);

	(void)do_rw_taskfile(drive, cmd);

	if (drq_int) {
		if (drive->dma)
			drive->waiting_for_dma = 0;
		hwif->expiry = expiry;
	}

	ide_execute_command(drive, cmd, ide_transfer_pc, timeout);

	return drq_int ? ide_started : ide_transfer_pc(drive);
}
EXPORT_SYMBOL_GPL(ide_issue_pc);