ide-atapi.c revision dfb7e621fa12c0579e88560ab176c5768f9e0bfb
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 22static 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 */ 31int 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} 72EXPORT_SYMBOL_GPL(ide_check_atapi_device); 73 74void ide_init_pc(struct ide_atapi_pc *pc) 75{ 76 memset(pc, 0, sizeof(*pc)); 77 pc->buf = pc->pc_buf; 78 pc->buf_size = IDE_PC_BUFFER_SIZE; 79} 80EXPORT_SYMBOL_GPL(ide_init_pc); 81 82/* 83 * Add a special packet command request to the tail of the request queue, 84 * and wait for it to be serviced. 85 */ 86int ide_queue_pc_tail(ide_drive_t *drive, struct gendisk *disk, 87 struct ide_atapi_pc *pc) 88{ 89 struct request *rq; 90 int error; 91 92 rq = blk_get_request(drive->queue, READ, __GFP_WAIT); 93 rq->cmd_type = REQ_TYPE_SPECIAL; 94 rq->special = (char *)pc; 95 96 if (pc->req_xfer) { 97 error = blk_rq_map_kern(drive->queue, rq, pc->buf, pc->req_xfer, 98 GFP_NOIO); 99 if (error) 100 goto put_req; 101 } 102 103 memcpy(rq->cmd, pc->c, 12); 104 if (drive->media == ide_tape) 105 rq->cmd[13] = REQ_IDETAPE_PC1; 106 error = blk_execute_rq(drive->queue, disk, rq, 0); 107put_req: 108 blk_put_request(rq); 109 return error; 110} 111EXPORT_SYMBOL_GPL(ide_queue_pc_tail); 112 113int ide_do_test_unit_ready(ide_drive_t *drive, struct gendisk *disk) 114{ 115 struct ide_atapi_pc pc; 116 117 ide_init_pc(&pc); 118 pc.c[0] = TEST_UNIT_READY; 119 120 return ide_queue_pc_tail(drive, disk, &pc); 121} 122EXPORT_SYMBOL_GPL(ide_do_test_unit_ready); 123 124int ide_do_start_stop(ide_drive_t *drive, struct gendisk *disk, int start) 125{ 126 struct ide_atapi_pc pc; 127 128 ide_init_pc(&pc); 129 pc.c[0] = START_STOP; 130 pc.c[4] = start; 131 132 if (drive->media == ide_tape) 133 pc.flags |= PC_FLAG_WAIT_FOR_DSC; 134 135 return ide_queue_pc_tail(drive, disk, &pc); 136} 137EXPORT_SYMBOL_GPL(ide_do_start_stop); 138 139int ide_set_media_lock(ide_drive_t *drive, struct gendisk *disk, int on) 140{ 141 struct ide_atapi_pc pc; 142 143 if ((drive->dev_flags & IDE_DFLAG_DOORLOCKING) == 0) 144 return 0; 145 146 ide_init_pc(&pc); 147 pc.c[0] = ALLOW_MEDIUM_REMOVAL; 148 pc.c[4] = on; 149 150 return ide_queue_pc_tail(drive, disk, &pc); 151} 152EXPORT_SYMBOL_GPL(ide_set_media_lock); 153 154void ide_create_request_sense_cmd(ide_drive_t *drive, struct ide_atapi_pc *pc) 155{ 156 ide_init_pc(pc); 157 pc->c[0] = REQUEST_SENSE; 158 if (drive->media == ide_floppy) { 159 pc->c[4] = 255; 160 pc->req_xfer = 18; 161 } else { 162 pc->c[4] = 20; 163 pc->req_xfer = 20; 164 } 165} 166EXPORT_SYMBOL_GPL(ide_create_request_sense_cmd); 167 168void ide_prep_sense(ide_drive_t *drive, struct request *rq) 169{ 170 struct request_sense *sense = &drive->sense_data; 171 struct request *sense_rq = &drive->sense_rq; 172 unsigned int cmd_len, sense_len; 173 int err; 174 175 debug_log("%s: enter\n", __func__); 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 "%s: failed to map sense buffer\n", 205 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} 220EXPORT_SYMBOL_GPL(ide_prep_sense); 221 222int 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 "%s: failed queue 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} 240EXPORT_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 */ 247void 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 pc->buf = bio_data(sense_rq->bio); /* pointer to mapped address */ 259 pc->req_xfer = blk_rq_bytes(sense_rq); 260 261 if (drive->media == ide_tape) 262 set_bit(IDE_AFLAG_IGNORE_DSC, &drive->atapi_flags); 263 264 /* 265 * Push back the failed request and put request sense on top 266 * of it. The failed command will be retried after sense data 267 * is acquired. 268 */ 269 blk_requeue_request(failed_rq->q, failed_rq); 270 drive->hwif->rq = NULL; 271 if (ide_queue_sense_rq(drive, pc)) { 272 blk_start_request(failed_rq); 273 ide_complete_rq(drive, -EIO, blk_rq_bytes(failed_rq)); 274 } 275} 276EXPORT_SYMBOL_GPL(ide_retry_pc); 277 278int ide_cd_expiry(ide_drive_t *drive) 279{ 280 struct request *rq = drive->hwif->rq; 281 unsigned long wait = 0; 282 283 debug_log("%s: rq->cmd[0]: 0x%x\n", __func__, rq->cmd[0]); 284 285 /* 286 * Some commands are *slow* and normally take a long time to complete. 287 * Usually we can use the ATAPI "disconnect" to bypass this, but not all 288 * commands/drives support that. Let ide_timer_expiry keep polling us 289 * for these. 290 */ 291 switch (rq->cmd[0]) { 292 case GPCMD_BLANK: 293 case GPCMD_FORMAT_UNIT: 294 case GPCMD_RESERVE_RZONE_TRACK: 295 case GPCMD_CLOSE_TRACK: 296 case GPCMD_FLUSH_CACHE: 297 wait = ATAPI_WAIT_PC; 298 break; 299 default: 300 if (!(rq->cmd_flags & REQ_QUIET)) 301 printk(KERN_INFO "cmd 0x%x timed out\n", 302 rq->cmd[0]); 303 wait = 0; 304 break; 305 } 306 return wait; 307} 308EXPORT_SYMBOL_GPL(ide_cd_expiry); 309 310int ide_cd_get_xferlen(struct request *rq) 311{ 312 if (blk_fs_request(rq)) 313 return 32768; 314 else if (blk_sense_request(rq) || blk_pc_request(rq) || 315 rq->cmd_type == REQ_TYPE_ATA_PC) 316 return blk_rq_bytes(rq); 317 else 318 return 0; 319} 320EXPORT_SYMBOL_GPL(ide_cd_get_xferlen); 321 322void 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} 332EXPORT_SYMBOL_GPL(ide_read_bcount_and_ireason); 333 334/* 335 * This is the usual interrupt handler which will be called during a packet 336 * command. We will transfer some of the data (as requested by the drive) 337 * and will re-point interrupt handler to us. 338 */ 339static ide_startstop_t ide_pc_intr(ide_drive_t *drive) 340{ 341 struct ide_atapi_pc *pc = drive->pc; 342 ide_hwif_t *hwif = drive->hwif; 343 struct ide_cmd *cmd = &hwif->cmd; 344 struct request *rq = hwif->rq; 345 const struct ide_tp_ops *tp_ops = hwif->tp_ops; 346 unsigned int timeout, done; 347 u16 bcount; 348 u8 stat, ireason, dsc = 0; 349 u8 write = !!(pc->flags & PC_FLAG_WRITING); 350 351 debug_log("Enter %s - interrupt handler\n", __func__); 352 353 timeout = (drive->media == ide_floppy) ? WAIT_FLOPPY_CMD 354 : WAIT_TAPE_CMD; 355 356 /* Clear the interrupt */ 357 stat = tp_ops->read_status(hwif); 358 359 if (pc->flags & PC_FLAG_DMA_IN_PROGRESS) { 360 int rc; 361 362 drive->waiting_for_dma = 0; 363 rc = hwif->dma_ops->dma_end(drive); 364 ide_dma_unmap_sg(drive, cmd); 365 366 if (rc || (drive->media == ide_tape && (stat & ATA_ERR))) { 367 if (drive->media == ide_floppy) 368 printk(KERN_ERR "%s: DMA %s error\n", 369 drive->name, rq_data_dir(pc->rq) 370 ? "write" : "read"); 371 pc->flags |= PC_FLAG_DMA_ERROR; 372 } else 373 pc->xferred = blk_rq_bytes(rq); 374 debug_log("%s: DMA finished\n", drive->name); 375 } 376 377 /* No more interrupts */ 378 if ((stat & ATA_DRQ) == 0) { 379 int uptodate, error; 380 381 debug_log("Packet command completed, %d bytes transferred\n", 382 pc->xferred); 383 384 pc->flags &= ~PC_FLAG_DMA_IN_PROGRESS; 385 386 local_irq_enable_in_hardirq(); 387 388 if (drive->media == ide_tape && 389 (stat & ATA_ERR) && rq->cmd[0] == REQUEST_SENSE) 390 stat &= ~ATA_ERR; 391 392 if ((stat & ATA_ERR) || (pc->flags & PC_FLAG_DMA_ERROR)) { 393 /* Error detected */ 394 debug_log("%s: I/O error\n", drive->name); 395 396 if (drive->media != ide_tape) 397 pc->rq->errors++; 398 399 if (rq->cmd[0] == REQUEST_SENSE) { 400 printk(KERN_ERR "%s: I/O error in request sense" 401 " command\n", drive->name); 402 return ide_do_reset(drive); 403 } 404 405 debug_log("[cmd %x]: check condition\n", rq->cmd[0]); 406 407 /* Retry operation */ 408 ide_retry_pc(drive); 409 410 /* queued, but not started */ 411 return ide_stopped; 412 } 413 pc->error = 0; 414 415 if ((pc->flags & PC_FLAG_WAIT_FOR_DSC) && (stat & ATA_DSC) == 0) 416 dsc = 1; 417 418 /* Command finished - Call the callback function */ 419 uptodate = drive->pc_callback(drive, dsc); 420 421 if (uptodate == 0) 422 drive->failed_pc = NULL; 423 424 if (blk_special_request(rq)) { 425 rq->errors = 0; 426 error = 0; 427 } else { 428 429 if (blk_fs_request(rq) == 0 && uptodate <= 0) { 430 if (rq->errors == 0) 431 rq->errors = -EIO; 432 } 433 434 error = uptodate ? 0 : -EIO; 435 } 436 437 ide_complete_rq(drive, error, blk_rq_bytes(rq)); 438 return ide_stopped; 439 } 440 441 if (pc->flags & PC_FLAG_DMA_IN_PROGRESS) { 442 pc->flags &= ~PC_FLAG_DMA_IN_PROGRESS; 443 printk(KERN_ERR "%s: The device wants to issue more interrupts " 444 "in DMA mode\n", drive->name); 445 ide_dma_off(drive); 446 return ide_do_reset(drive); 447 } 448 449 /* Get the number of bytes to transfer on this interrupt. */ 450 ide_read_bcount_and_ireason(drive, &bcount, &ireason); 451 452 if (ireason & ATAPI_COD) { 453 printk(KERN_ERR "%s: CoD != 0 in %s\n", drive->name, __func__); 454 return ide_do_reset(drive); 455 } 456 457 if (((ireason & ATAPI_IO) == ATAPI_IO) == write) { 458 /* Hopefully, we will never get here */ 459 printk(KERN_ERR "%s: We wanted to %s, but the device wants us " 460 "to %s!\n", drive->name, 461 (ireason & ATAPI_IO) ? "Write" : "Read", 462 (ireason & ATAPI_IO) ? "Read" : "Write"); 463 return ide_do_reset(drive); 464 } 465 466 done = min_t(unsigned int, bcount, cmd->nleft); 467 ide_pio_bytes(drive, cmd, write, done); 468 469 /* Update transferred byte count */ 470 pc->xferred += done; 471 472 bcount -= done; 473 474 if (bcount) 475 ide_pad_transfer(drive, write, bcount); 476 477 debug_log("[cmd %x] transferred %d bytes, padded %d bytes\n", 478 rq->cmd[0], done, bcount); 479 480 /* And set the interrupt handler again */ 481 ide_set_handler(drive, ide_pc_intr, timeout); 482 return ide_started; 483} 484 485static void ide_init_packet_cmd(struct ide_cmd *cmd, u8 valid_tf, 486 u16 bcount, u8 dma) 487{ 488 cmd->protocol = dma ? ATAPI_PROT_DMA : ATAPI_PROT_PIO; 489 cmd->valid.out.tf = IDE_VALID_LBAH | IDE_VALID_LBAM | 490 IDE_VALID_FEATURE | valid_tf; 491 cmd->tf.command = ATA_CMD_PACKET; 492 cmd->tf.feature = dma; /* Use PIO/DMA */ 493 cmd->tf.lbam = bcount & 0xff; 494 cmd->tf.lbah = (bcount >> 8) & 0xff; 495} 496 497static u8 ide_read_ireason(ide_drive_t *drive) 498{ 499 struct ide_taskfile tf; 500 501 drive->hwif->tp_ops->tf_read(drive, &tf, IDE_VALID_NSECT); 502 503 return tf.nsect & 3; 504} 505 506static u8 ide_wait_ireason(ide_drive_t *drive, u8 ireason) 507{ 508 int retries = 100; 509 510 while (retries-- && ((ireason & ATAPI_COD) == 0 || 511 (ireason & ATAPI_IO))) { 512 printk(KERN_ERR "%s: (IO,CoD != (0,1) while issuing " 513 "a packet command, retrying\n", drive->name); 514 udelay(100); 515 ireason = ide_read_ireason(drive); 516 if (retries == 0) { 517 printk(KERN_ERR "%s: (IO,CoD != (0,1) while issuing " 518 "a packet command, ignoring\n", 519 drive->name); 520 ireason |= ATAPI_COD; 521 ireason &= ~ATAPI_IO; 522 } 523 } 524 525 return ireason; 526} 527 528static int ide_delayed_transfer_pc(ide_drive_t *drive) 529{ 530 /* Send the actual packet */ 531 drive->hwif->tp_ops->output_data(drive, NULL, drive->pc->c, 12); 532 533 /* Timeout for the packet command */ 534 return WAIT_FLOPPY_CMD; 535} 536 537static ide_startstop_t ide_transfer_pc(ide_drive_t *drive) 538{ 539 struct ide_atapi_pc *uninitialized_var(pc); 540 ide_hwif_t *hwif = drive->hwif; 541 struct request *rq = hwif->rq; 542 ide_expiry_t *expiry; 543 unsigned int timeout; 544 int cmd_len; 545 ide_startstop_t startstop; 546 u8 ireason; 547 548 if (ide_wait_stat(&startstop, drive, ATA_DRQ, ATA_BUSY, WAIT_READY)) { 549 printk(KERN_ERR "%s: Strange, packet command initiated yet " 550 "DRQ isn't asserted\n", drive->name); 551 return startstop; 552 } 553 554 if (drive->atapi_flags & IDE_AFLAG_DRQ_INTERRUPT) { 555 if (drive->dma) 556 drive->waiting_for_dma = 1; 557 } 558 559 if (dev_is_idecd(drive)) { 560 /* ATAPI commands get padded out to 12 bytes minimum */ 561 cmd_len = COMMAND_SIZE(rq->cmd[0]); 562 if (cmd_len < ATAPI_MIN_CDB_BYTES) 563 cmd_len = ATAPI_MIN_CDB_BYTES; 564 565 timeout = rq->timeout; 566 expiry = ide_cd_expiry; 567 } else { 568 pc = drive->pc; 569 570 cmd_len = ATAPI_MIN_CDB_BYTES; 571 572 /* 573 * If necessary schedule the packet transfer to occur 'timeout' 574 * miliseconds later in ide_delayed_transfer_pc() after the 575 * device says it's ready for a packet. 576 */ 577 if (drive->atapi_flags & IDE_AFLAG_ZIP_DRIVE) { 578 timeout = drive->pc_delay; 579 expiry = &ide_delayed_transfer_pc; 580 } else { 581 timeout = (drive->media == ide_floppy) ? WAIT_FLOPPY_CMD 582 : WAIT_TAPE_CMD; 583 expiry = NULL; 584 } 585 586 ireason = ide_read_ireason(drive); 587 if (drive->media == ide_tape) 588 ireason = ide_wait_ireason(drive, ireason); 589 590 if ((ireason & ATAPI_COD) == 0 || (ireason & ATAPI_IO)) { 591 printk(KERN_ERR "%s: (IO,CoD) != (0,1) while issuing " 592 "a packet command\n", drive->name); 593 594 return ide_do_reset(drive); 595 } 596 } 597 598 hwif->expiry = expiry; 599 600 /* Set the interrupt routine */ 601 ide_set_handler(drive, 602 (dev_is_idecd(drive) ? drive->irq_handler 603 : ide_pc_intr), 604 timeout); 605 606 /* Send the actual packet */ 607 if ((drive->atapi_flags & IDE_AFLAG_ZIP_DRIVE) == 0) 608 hwif->tp_ops->output_data(drive, NULL, rq->cmd, cmd_len); 609 610 /* Begin DMA, if necessary */ 611 if (dev_is_idecd(drive)) { 612 if (drive->dma) 613 hwif->dma_ops->dma_start(drive); 614 } else { 615 if (pc->flags & PC_FLAG_DMA_OK) { 616 pc->flags |= PC_FLAG_DMA_IN_PROGRESS; 617 hwif->dma_ops->dma_start(drive); 618 } 619 } 620 621 return ide_started; 622} 623 624ide_startstop_t ide_issue_pc(ide_drive_t *drive, struct ide_cmd *cmd) 625{ 626 struct ide_atapi_pc *pc; 627 ide_hwif_t *hwif = drive->hwif; 628 ide_expiry_t *expiry = NULL; 629 struct request *rq = hwif->rq; 630 unsigned int timeout, bytes; 631 u16 bcount; 632 u8 valid_tf; 633 u8 drq_int = !!(drive->atapi_flags & IDE_AFLAG_DRQ_INTERRUPT); 634 635 if (dev_is_idecd(drive)) { 636 valid_tf = IDE_VALID_NSECT | IDE_VALID_LBAL; 637 bcount = ide_cd_get_xferlen(rq); 638 expiry = ide_cd_expiry; 639 timeout = ATAPI_WAIT_PC; 640 641 if (drive->dma) 642 drive->dma = !ide_dma_prepare(drive, cmd); 643 } else { 644 pc = drive->pc; 645 646 /* We haven't transferred any data yet */ 647 pc->xferred = 0; 648 649 valid_tf = IDE_VALID_DEVICE; 650 bytes = blk_rq_bytes(rq); 651 652 bcount = ((drive->media == ide_tape) ? bytes 653 : min_t(unsigned int, 654 bytes, 63 * 1024)); 655 656 if (pc->flags & PC_FLAG_DMA_ERROR) { 657 pc->flags &= ~PC_FLAG_DMA_ERROR; 658 ide_dma_off(drive); 659 } 660 661 if (pc->flags & PC_FLAG_DMA_OK) 662 drive->dma = !ide_dma_prepare(drive, cmd); 663 664 if (!drive->dma) 665 pc->flags &= ~PC_FLAG_DMA_OK; 666 667 timeout = (drive->media == ide_floppy) ? WAIT_FLOPPY_CMD 668 : WAIT_TAPE_CMD; 669 } 670 671 ide_init_packet_cmd(cmd, valid_tf, bcount, drive->dma); 672 673 (void)do_rw_taskfile(drive, cmd); 674 675 if (drq_int) { 676 if (drive->dma) 677 drive->waiting_for_dma = 0; 678 hwif->expiry = expiry; 679 } 680 681 ide_execute_command(drive, cmd, ide_transfer_pc, timeout); 682 683 return drq_int ? ide_started : ide_transfer_pc(drive); 684} 685EXPORT_SYMBOL_GPL(ide_issue_pc); 686