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);