drivers/ide/ide-atapi.c

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