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 (rq->cmd_type == REQ_TYPE_SENSE || 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, ELEVATOR_INSERT_FRONT);
 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         drive->hwif->rq = NULL;
 267         ide_requeue_and_plug(drive, failed_rq);
 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         switch (rq->cmd_type) {
 310         case REQ_TYPE_FS:
 311                 return 32768;
 312         case REQ_TYPE_SENSE:
 313         case REQ_TYPE_BLOCK_PC:
 314         case REQ_TYPE_ATA_PC:
 315                 return blk_rq_bytes(rq);
 316         default:
 317                 return 0;
 318         }
 319 }
 320 EXPORT_SYMBOL_GPL(ide_cd_get_xferlen);
 321
 322 void ide_read_bcount_and_ireason(ide_drive_t *drive, u16 *bcount, u8 *ireason)
 323 {
 324         struct ide_taskfile tf;
 325
 326         drive->hwif->tp_ops->tf_read(drive, &tf, IDE_VALID_NSECT |
 327                                      IDE_VALID_LBAM | IDE_VALID_LBAH);
 328
 329         *bcount = (tf.lbah << 8) | tf.lbam;
 330         *ireason = tf.nsect & 3;
 331 }
 332 EXPORT_SYMBOL_GPL(ide_read_bcount_and_ireason);
 333
 334 /*
 335  * Check the contents of the interrupt reason register and attempt to recover if
 336  * there are problems.
 337  *
 338  * Returns:
 339  * - 0 if everything's ok
 340  * - 1 if the request has to be terminated.
 341  */
 342 int ide_check_ireason(ide_drive_t *drive, struct request *rq, int len,
 343                       int ireason, int rw)
 344 {
 345         ide_hwif_t *hwif = drive->hwif;
 346
 347         debug_log("ireason: 0x%x, rw: 0x%x\n", ireason, rw);
 348
 349         if (ireason == (!rw << 1))
 350                 return 0;
 351         else if (ireason == (rw << 1)) {
 352                 printk(KERN_ERR PFX "%s: %s: wrong transfer direction!\n",
 353                                 drive->name, __func__);
 354
 355                 if (dev_is_idecd(drive))
 356                         ide_pad_transfer(drive, rw, len);
 357         } else if (!rw && ireason == ATAPI_COD) {
 358                 if (dev_is_idecd(drive)) {
 359                         /*
 360                          * Some drives (ASUS) seem to tell us that status info
 361                          * is available.  Just get it and ignore.
 362                          */
 363                         (void)hwif->tp_ops->read_status(hwif);
 364                         return 0;
 365                 }
 366         } else {
 367                 if (ireason & ATAPI_COD)
 368                         printk(KERN_ERR PFX "%s: CoD != 0 in %s\n", drive->name,
 369                                         __func__);
 370
 371                 /* drive wants a command packet, or invalid ireason... */
 372                 printk(KERN_ERR PFX "%s: %s: bad interrupt reason 0x%02x\n",
 373                                 drive->name, __func__, ireason);
 374         }
 375
 376         if (dev_is_idecd(drive) && rq->cmd_type == REQ_TYPE_ATA_PC)
 377                 rq->cmd_flags |= REQ_FAILED;
 378
 379         return 1;
 380 }
 381 EXPORT_SYMBOL_GPL(ide_check_ireason);
 382
 383 /*
 384  * This is the usual interrupt handler which will be called during a packet
 385  * command.  We will transfer some of the data (as requested by the drive)
 386  * and will re-point interrupt handler to us.
 387  */
 388 static ide_startstop_t ide_pc_intr(ide_drive_t *drive)
 389 {
 390         struct ide_atapi_pc *pc = drive->pc;
 391         ide_hwif_t *hwif = drive->hwif;
 392         struct ide_cmd *cmd = &hwif->cmd;
 393         struct request *rq = hwif->rq;
 394         const struct ide_tp_ops *tp_ops = hwif->tp_ops;
 395         unsigned int timeout, done;
 396         u16 bcount;
 397         u8 stat, ireason, dsc = 0;
 398         u8 write = !!(pc->flags & PC_FLAG_WRITING);
 399
 400         debug_log("Enter %s - interrupt handler\n", __func__);
 401
 402         timeout = (drive->media == ide_floppy) ? WAIT_FLOPPY_CMD
 403                                                : WAIT_TAPE_CMD;
 404
 405         /* Clear the interrupt */
 406         stat = tp_ops->read_status(hwif);
 407
 408         if (pc->flags & PC_FLAG_DMA_IN_PROGRESS) {
 409                 int rc;
 410
 411                 drive->waiting_for_dma = 0;
 412                 rc = hwif->dma_ops->dma_end(drive);
 413                 ide_dma_unmap_sg(drive, cmd);
 414
 415                 if (rc || (drive->media == ide_tape && (stat & ATA_ERR))) {
 416                         if (drive->media == ide_floppy)
 417                                 printk(KERN_ERR PFX "%s: DMA %s error\n",
 418                                         drive->name, rq_data_dir(pc->rq)
 419                                                      ? "write" : "read");
 420                         pc->flags |= PC_FLAG_DMA_ERROR;
 421                 } else
 422                         rq->resid_len = 0;
 423                 debug_log("%s: DMA finished\n", drive->name);
 424         }
 425
 426         /* No more interrupts */
 427         if ((stat & ATA_DRQ) == 0) {
 428                 int uptodate, error;
 429
 430                 debug_log("Packet command completed, %d bytes transferred\n",
 431                           blk_rq_bytes(rq));
 432
 433                 pc->flags &= ~PC_FLAG_DMA_IN_PROGRESS;
 434
 435                 local_irq_enable_in_hardirq();
 436
 437                 if (drive->media == ide_tape &&
 438                     (stat & ATA_ERR) && rq->cmd[0] == REQUEST_SENSE)
 439                         stat &= ~ATA_ERR;
 440
 441                 if ((stat & ATA_ERR) || (pc->flags & PC_FLAG_DMA_ERROR)) {
 442                         /* Error detected */
 443                         debug_log("%s: I/O error\n", drive->name);
 444
 445                         if (drive->media != ide_tape)
 446                                 pc->rq->errors++;
 447
 448                         if (rq->cmd[0] == REQUEST_SENSE) {
 449                                 printk(KERN_ERR PFX "%s: I/O error in request "
 450                                                 "sense command\n", drive->name);
 451                                 return ide_do_reset(drive);
 452                         }
 453
 454                         debug_log("[cmd %x]: check condition\n", rq->cmd[0]);
 455
 456                         /* Retry operation */
 457                         ide_retry_pc(drive);
 458
 459                         /* queued, but not started */
 460                         return ide_stopped;
 461                 }
 462                 pc->error = 0;
 463
 464                 if ((pc->flags & PC_FLAG_WAIT_FOR_DSC) && (stat & ATA_DSC) == 0)
 465                         dsc = 1;
 466
 467                 /*
 468                  * ->pc_callback() might change rq->data_len for
 469                  * residual count, cache total length.
 470                  */
 471                 done = blk_rq_bytes(rq);
 472
 473                 /* Command finished - Call the callback function */
 474                 uptodate = drive->pc_callback(drive, dsc);
 475
 476                 if (uptodate == 0)
 477                         drive->failed_pc = NULL;
 478
 479                 if (rq->cmd_type == REQ_TYPE_SPECIAL) {
 480                         rq->errors = 0;
 481                         error = 0;
 482                 } else {
 483
 484                         if (rq->cmd_type != REQ_TYPE_FS && uptodate <= 0) {
 485                                 if (rq->errors == 0)
 486                                         rq->errors = -EIO;
 487                         }
 488
 489                         error = uptodate ? 0 : -EIO;
 490                 }
 491
 492                 ide_complete_rq(drive, error, blk_rq_bytes(rq));
 493                 return ide_stopped;
 494         }
 495
 496         if (pc->flags & PC_FLAG_DMA_IN_PROGRESS) {
 497                 pc->flags &= ~PC_FLAG_DMA_IN_PROGRESS;
 498                 printk(KERN_ERR PFX "%s: The device wants to issue more "
 499                                 "interrupts in DMA mode\n", drive->name);
 500                 ide_dma_off(drive);
 501                 return ide_do_reset(drive);
 502         }
 503
 504         /* Get the number of bytes to transfer on this interrupt. */
 505         ide_read_bcount_and_ireason(drive, &bcount, &ireason);
 506
 507         if (ide_check_ireason(drive, rq, bcount, ireason, write))
 508                 return ide_do_reset(drive);
 509
 510         done = min_t(unsigned int, bcount, cmd->nleft);
 511         ide_pio_bytes(drive, cmd, write, done);
 512
 513         /* Update transferred byte count */
 514         rq->resid_len -= done;
 515
 516         bcount -= done;
 517
 518         if (bcount)
 519                 ide_pad_transfer(drive, write, bcount);
 520
 521         debug_log("[cmd %x] transferred %d bytes, padded %d bytes, resid: %u\n",
 522                   rq->cmd[0], done, bcount, rq->resid_len);
 523
 524         /* And set the interrupt handler again */
 525         ide_set_handler(drive, ide_pc_intr, timeout);
 526         return ide_started;
 527 }
 528
 529 static void ide_init_packet_cmd(struct ide_cmd *cmd, u8 valid_tf,
 530                                 u16 bcount, u8 dma)
 531 {
 532         cmd->protocol = dma ? ATAPI_PROT_DMA : ATAPI_PROT_PIO;
 533         cmd->valid.out.tf = IDE_VALID_LBAH | IDE_VALID_LBAM |
 534                             IDE_VALID_FEATURE | valid_tf;
 535         cmd->tf.command = ATA_CMD_PACKET;
 536         cmd->tf.feature = dma;          /* Use PIO/DMA */
 537         cmd->tf.lbam    = bcount & 0xff;
 538         cmd->tf.lbah    = (bcount >> 8) & 0xff;
 539 }
 540
 541 static u8 ide_read_ireason(ide_drive_t *drive)
 542 {
 543         struct ide_taskfile tf;
 544
 545         drive->hwif->tp_ops->tf_read(drive, &tf, IDE_VALID_NSECT);
 546
 547         return tf.nsect & 3;
 548 }
 549
 550 static u8 ide_wait_ireason(ide_drive_t *drive, u8 ireason)
 551 {
 552         int retries = 100;
 553
 554         while (retries-- && ((ireason & ATAPI_COD) == 0 ||
 555                 (ireason & ATAPI_IO))) {
 556                 printk(KERN_ERR PFX "%s: (IO,CoD != (0,1) while issuing "
 557                                 "a packet command, retrying\n", drive->name);
 558                 udelay(100);
 559                 ireason = ide_read_ireason(drive);
 560                 if (retries == 0) {
 561                         printk(KERN_ERR PFX "%s: (IO,CoD != (0,1) while issuing"
 562                                         " a packet command, ignoring\n",
 563                                         drive->name);
 564                         ireason |= ATAPI_COD;
 565                         ireason &= ~ATAPI_IO;
 566                 }
 567         }
 568
 569         return ireason;
 570 }
 571
 572 static int ide_delayed_transfer_pc(ide_drive_t *drive)
 573 {
 574         /* Send the actual packet */
 575         drive->hwif->tp_ops->output_data(drive, NULL, drive->pc->c, 12);
 576
 577         /* Timeout for the packet command */
 578         return WAIT_FLOPPY_CMD;
 579 }
 580
 581 static ide_startstop_t ide_transfer_pc(ide_drive_t *drive)
 582 {
 583         struct ide_atapi_pc *uninitialized_var(pc);
 584         ide_hwif_t *hwif = drive->hwif;
 585         struct request *rq = hwif->rq;
 586         ide_expiry_t *expiry;
 587         unsigned int timeout;
 588         int cmd_len;
 589         ide_startstop_t startstop;
 590         u8 ireason;
 591
 592         if (ide_wait_stat(&startstop, drive, ATA_DRQ, ATA_BUSY, WAIT_READY)) {
 593                 printk(KERN_ERR PFX "%s: Strange, packet command initiated yet "
 594                                 "DRQ isn't asserted\n", drive->name);
 595                 return startstop;
 596         }
 597
 598         if (drive->atapi_flags & IDE_AFLAG_DRQ_INTERRUPT) {
 599                 if (drive->dma)
 600                         drive->waiting_for_dma = 1;
 601         }
 602
 603         if (dev_is_idecd(drive)) {
 604                 /* ATAPI commands get padded out to 12 bytes minimum */
 605                 cmd_len = COMMAND_SIZE(rq->cmd[0]);
 606                 if (cmd_len < ATAPI_MIN_CDB_BYTES)
 607                         cmd_len = ATAPI_MIN_CDB_BYTES;
 608
 609                 timeout = rq->timeout;
 610                 expiry  = ide_cd_expiry;
 611         } else {
 612                 pc = drive->pc;
 613
 614                 cmd_len = ATAPI_MIN_CDB_BYTES;
 615
 616                 /*
 617                  * If necessary schedule the packet transfer to occur 'timeout'
 618                  * milliseconds later in ide_delayed_transfer_pc() after the
 619                  * device says it's ready for a packet.
 620                  */
 621                 if (drive->atapi_flags & IDE_AFLAG_ZIP_DRIVE) {
 622                         timeout = drive->pc_delay;
 623                         expiry = &ide_delayed_transfer_pc;
 624                 } else {
 625                         timeout = (drive->media == ide_floppy) ? WAIT_FLOPPY_CMD
 626                                                                : WAIT_TAPE_CMD;
 627                         expiry = NULL;
 628                 }
 629
 630                 ireason = ide_read_ireason(drive);
 631                 if (drive->media == ide_tape)
 632                         ireason = ide_wait_ireason(drive, ireason);
 633
 634                 if ((ireason & ATAPI_COD) == 0 || (ireason & ATAPI_IO)) {
 635                         printk(KERN_ERR PFX "%s: (IO,CoD) != (0,1) while "
 636                                 "issuing a packet command\n", drive->name);
 637
 638                         return ide_do_reset(drive);
 639                 }
 640         }
 641
 642         hwif->expiry = expiry;
 643
 644         /* Set the interrupt routine */
 645         ide_set_handler(drive,
 646                         (dev_is_idecd(drive) ? drive->irq_handler
 647                                              : ide_pc_intr),
 648                         timeout);
 649
 650         /* Send the actual packet */
 651         if ((drive->atapi_flags & IDE_AFLAG_ZIP_DRIVE) == 0)
 652                 hwif->tp_ops->output_data(drive, NULL, rq->cmd, cmd_len);
 653
 654         /* Begin DMA, if necessary */
 655         if (dev_is_idecd(drive)) {
 656                 if (drive->dma)
 657                         hwif->dma_ops->dma_start(drive);
 658         } else {
 659                 if (pc->flags & PC_FLAG_DMA_OK) {
 660                         pc->flags |= PC_FLAG_DMA_IN_PROGRESS;
 661                         hwif->dma_ops->dma_start(drive);
 662                 }
 663         }
 664
 665         return ide_started;
 666 }
 667
 668 ide_startstop_t ide_issue_pc(ide_drive_t *drive, struct ide_cmd *cmd)
 669 {
 670         struct ide_atapi_pc *pc;
 671         ide_hwif_t *hwif = drive->hwif;
 672         ide_expiry_t *expiry = NULL;
 673         struct request *rq = hwif->rq;
 674         unsigned int timeout, bytes;
 675         u16 bcount;
 676         u8 valid_tf;
 677         u8 drq_int = !!(drive->atapi_flags & IDE_AFLAG_DRQ_INTERRUPT);
 678
 679         if (dev_is_idecd(drive)) {
 680                 valid_tf = IDE_VALID_NSECT | IDE_VALID_LBAL;
 681                 bcount = ide_cd_get_xferlen(rq);
 682                 expiry = ide_cd_expiry;
 683                 timeout = ATAPI_WAIT_PC;
 684
 685                 if (drive->dma)
 686                         drive->dma = !ide_dma_prepare(drive, cmd);
 687         } else {
 688                 pc = drive->pc;
 689
 690                 valid_tf = IDE_VALID_DEVICE;
 691                 bytes = blk_rq_bytes(rq);
 692                 bcount = ((drive->media == ide_tape) ? bytes
 693                                                      : min_t(unsigned int,
 694                                                              bytes, 63 * 1024));
 695
 696                 /* We haven't transferred any data yet */
 697                 rq->resid_len = bcount;
 698
 699                 if (pc->flags & PC_FLAG_DMA_ERROR) {
 700                         pc->flags &= ~PC_FLAG_DMA_ERROR;
 701                         ide_dma_off(drive);
 702                 }
 703
 704                 if (pc->flags & PC_FLAG_DMA_OK)
 705                         drive->dma = !ide_dma_prepare(drive, cmd);
 706
 707                 if (!drive->dma)
 708                         pc->flags &= ~PC_FLAG_DMA_OK;
 709
 710                 timeout = (drive->media == ide_floppy) ? WAIT_FLOPPY_CMD
 711                                                        : WAIT_TAPE_CMD;
 712         }
 713
 714         ide_init_packet_cmd(cmd, valid_tf, bcount, drive->dma);
 715
 716         (void)do_rw_taskfile(drive, cmd);
 717
 718         if (drq_int) {
 719                 if (drive->dma)
 720                         drive->waiting_for_dma = 0;
 721                 hwif->expiry = expiry;
 722         }
 723
 724         ide_execute_command(drive, cmd, ide_transfer_pc, timeout);
 725
 726         return drq_int ? ide_started : ide_transfer_pc(drive);
 727 }
 728 EXPORT_SYMBOL_GPL(ide_issue_pc);