4 * Basic PIO and command management functionality.
6 * This code was split off from ide.c. See ide.c for history and original
9 * This program is free software; you can redistribute it and/or modify it
10 * under the terms of the GNU General Public License as published by the
11 * Free Software Foundation; either version 2, or (at your option) any
14 * This program is distributed in the hope that it will be useful, but
15 * WITHOUT ANY WARRANTY; without even the implied warranty of
16 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
17 * General Public License for more details.
19 * For the avoidance of doubt the "preferred form" of this code is one which
20 * is in an open non patent encumbered format. Where cryptographic key signing
21 * forms part of the process of creating an executable the information
22 * including keys needed to generate an equivalently functional executable
23 * are deemed to be part of the source code.
27 #include <linux/module.h>
28 #include <linux/types.h>
29 #include <linux/string.h>
30 #include <linux/kernel.h>
31 #include <linux/timer.h>
33 #include <linux/interrupt.h>
34 #include <linux/major.h>
35 #include <linux/errno.h>
36 #include <linux/genhd.h>
37 #include <linux/blkpg.h>
38 #include <linux/slab.h>
39 #include <linux/init.h>
40 #include <linux/pci.h>
41 #include <linux/delay.h>
42 #include <linux/ide.h>
43 #include <linux/completion.h>
44 #include <linux/reboot.h>
45 #include <linux/cdrom.h>
46 #include <linux/seq_file.h>
47 #include <linux/device.h>
48 #include <linux/kmod.h>
49 #include <linux/scatterlist.h>
50 #include <linux/bitops.h>
52 #include <asm/byteorder.h>
54 #include <asm/uaccess.h>
57 int ide_end_rq(ide_drive_t *drive, struct request *rq, int error,
58 unsigned int nr_bytes)
61 * decide whether to reenable DMA -- 3 is a random magic for now,
62 * if we DMA timeout more than 3 times, just stay in PIO
64 if ((drive->dev_flags & IDE_DFLAG_DMA_PIO_RETRY) &&
65 drive->retry_pio <= 3) {
66 drive->dev_flags &= ~IDE_DFLAG_DMA_PIO_RETRY;
70 return blk_end_request(rq, error, nr_bytes);
72 EXPORT_SYMBOL_GPL(ide_end_rq);
74 void ide_complete_cmd(ide_drive_t *drive, struct ide_cmd *cmd, u8 stat, u8 err)
76 const struct ide_tp_ops *tp_ops = drive->hwif->tp_ops;
77 struct ide_taskfile *tf = &cmd->tf;
78 struct request *rq = cmd->rq;
79 u8 tf_cmd = tf->command;
84 if (cmd->ftf_flags & IDE_FTFLAG_IN_DATA) {
87 tp_ops->input_data(drive, cmd, data, 2);
89 cmd->tf.data = data[0];
90 cmd->hob.data = data[1];
93 ide_tf_readback(drive, cmd);
95 if ((cmd->tf_flags & IDE_TFLAG_CUSTOM_HANDLER) &&
96 tf_cmd == ATA_CMD_IDLEIMMEDIATE) {
97 if (tf->lbal != 0xc4) {
98 printk(KERN_ERR "%s: head unload failed!\n",
100 ide_tf_dump(drive->name, cmd);
102 drive->dev_flags |= IDE_DFLAG_PARKED;
105 if (rq && rq->cmd_type == REQ_TYPE_ATA_TASKFILE) {
106 struct ide_cmd *orig_cmd = rq->special;
108 if (cmd->tf_flags & IDE_TFLAG_DYN)
111 memcpy(orig_cmd, cmd, sizeof(*cmd));
115 /* obsolete, blk_rq_bytes() should be used instead */
116 unsigned int ide_rq_bytes(struct request *rq)
118 if (blk_pc_request(rq))
121 return rq->hard_cur_sectors << 9;
123 EXPORT_SYMBOL_GPL(ide_rq_bytes);
125 int ide_complete_rq(ide_drive_t *drive, int error, unsigned int nr_bytes)
127 ide_hwif_t *hwif = drive->hwif;
128 struct request *rq = hwif->rq;
132 * if failfast is set on a request, override number of sectors
133 * and complete the whole request right now
135 if (blk_noretry_request(rq) && error <= 0)
136 nr_bytes = rq->hard_nr_sectors << 9;
138 rc = ide_end_rq(drive, rq, error, nr_bytes);
144 EXPORT_SYMBOL(ide_complete_rq);
146 void ide_kill_rq(ide_drive_t *drive, struct request *rq)
148 u8 drv_req = blk_special_request(rq) && rq->rq_disk;
149 u8 media = drive->media;
151 drive->failed_pc = NULL;
153 if ((media == ide_floppy || media == ide_tape) && drv_req) {
155 ide_complete_rq(drive, 0, blk_rq_bytes(rq));
157 if (media == ide_tape)
158 rq->errors = IDE_DRV_ERROR_GENERAL;
159 else if (blk_fs_request(rq) == 0 && rq->errors == 0)
161 ide_complete_rq(drive, -EIO, ide_rq_bytes(rq));
165 static void ide_tf_set_specify_cmd(ide_drive_t *drive, struct ide_taskfile *tf)
167 tf->nsect = drive->sect;
168 tf->lbal = drive->sect;
169 tf->lbam = drive->cyl;
170 tf->lbah = drive->cyl >> 8;
171 tf->device = (drive->head - 1) | drive->select;
172 tf->command = ATA_CMD_INIT_DEV_PARAMS;
175 static void ide_tf_set_restore_cmd(ide_drive_t *drive, struct ide_taskfile *tf)
177 tf->nsect = drive->sect;
178 tf->command = ATA_CMD_RESTORE;
181 static void ide_tf_set_setmult_cmd(ide_drive_t *drive, struct ide_taskfile *tf)
183 tf->nsect = drive->mult_req;
184 tf->command = ATA_CMD_SET_MULTI;
187 static ide_startstop_t ide_disk_special(ide_drive_t *drive)
189 special_t *s = &drive->special;
192 memset(&cmd, 0, sizeof(cmd));
193 cmd.protocol = ATA_PROT_NODATA;
195 if (s->b.set_geometry) {
196 s->b.set_geometry = 0;
197 ide_tf_set_specify_cmd(drive, &cmd.tf);
198 } else if (s->b.recalibrate) {
199 s->b.recalibrate = 0;
200 ide_tf_set_restore_cmd(drive, &cmd.tf);
201 } else if (s->b.set_multmode) {
202 s->b.set_multmode = 0;
203 ide_tf_set_setmult_cmd(drive, &cmd.tf);
207 cmd.valid.out.tf = IDE_VALID_OUT_TF | IDE_VALID_DEVICE;
208 cmd.valid.in.tf = IDE_VALID_IN_TF | IDE_VALID_DEVICE;
209 cmd.tf_flags = IDE_TFLAG_CUSTOM_HANDLER;
211 do_rw_taskfile(drive, &cmd);
217 * do_special - issue some special commands
218 * @drive: drive the command is for
220 * do_special() is used to issue ATA_CMD_INIT_DEV_PARAMS,
221 * ATA_CMD_RESTORE and ATA_CMD_SET_MULTI commands to a drive.
223 * It used to do much more, but has been scaled back.
226 static ide_startstop_t do_special (ide_drive_t *drive)
228 special_t *s = &drive->special;
231 printk("%s: do_special: 0x%02x\n", drive->name, s->all);
233 if (drive->media == ide_disk)
234 return ide_disk_special(drive);
241 void ide_map_sg(ide_drive_t *drive, struct ide_cmd *cmd)
243 ide_hwif_t *hwif = drive->hwif;
244 struct scatterlist *sg = hwif->sg_table;
245 struct request *rq = cmd->rq;
247 cmd->sg_nents = blk_rq_map_sg(drive->queue, rq, sg);
249 EXPORT_SYMBOL_GPL(ide_map_sg);
251 void ide_init_sg_cmd(struct ide_cmd *cmd, unsigned int nr_bytes)
253 cmd->nbytes = cmd->nleft = nr_bytes;
257 EXPORT_SYMBOL_GPL(ide_init_sg_cmd);
260 * execute_drive_command - issue special drive command
261 * @drive: the drive to issue the command on
262 * @rq: the request structure holding the command
264 * execute_drive_cmd() issues a special drive command, usually
265 * initiated by ioctl() from the external hdparm program. The
266 * command can be a drive command, drive task or taskfile
267 * operation. Weirdly you can call it with NULL to wait for
268 * all commands to finish. Don't do this as that is due to change
271 static ide_startstop_t execute_drive_cmd (ide_drive_t *drive,
274 struct ide_cmd *cmd = rq->special;
277 if (cmd->protocol == ATA_PROT_PIO) {
278 ide_init_sg_cmd(cmd, rq->nr_sectors << 9);
279 ide_map_sg(drive, cmd);
282 return do_rw_taskfile(drive, cmd);
286 * NULL is actually a valid way of waiting for
287 * all current requests to be flushed from the queue.
290 printk("%s: DRIVE_CMD (null)\n", drive->name);
293 ide_complete_rq(drive, 0, blk_rq_bytes(rq));
298 static ide_startstop_t ide_special_rq(ide_drive_t *drive, struct request *rq)
304 case REQ_UNPARK_HEADS:
305 return ide_do_park_unpark(drive, rq);
306 case REQ_DEVSET_EXEC:
307 return ide_do_devset(drive, rq);
308 case REQ_DRIVE_RESET:
309 return ide_do_reset(drive);
316 * start_request - start of I/O and command issuing for IDE
318 * start_request() initiates handling of a new I/O request. It
319 * accepts commands and I/O (read/write) requests.
321 * FIXME: this function needs a rename
324 static ide_startstop_t start_request (ide_drive_t *drive, struct request *rq)
326 ide_startstop_t startstop;
328 BUG_ON(!blk_rq_started(rq));
331 printk("%s: start_request: current=0x%08lx\n",
332 drive->hwif->name, (unsigned long) rq);
335 /* bail early if we've exceeded max_failures */
336 if (drive->max_failures && (drive->failures > drive->max_failures)) {
337 rq->cmd_flags |= REQ_FAILED;
341 if (blk_pm_request(rq))
342 ide_check_pm_state(drive, rq);
344 drive->hwif->tp_ops->dev_select(drive);
345 if (ide_wait_stat(&startstop, drive, drive->ready_stat,
346 ATA_BUSY | ATA_DRQ, WAIT_READY)) {
347 printk(KERN_ERR "%s: drive not ready for command\n", drive->name);
350 if (!drive->special.all) {
351 struct ide_driver *drv;
354 * We reset the drive so we need to issue a SETFEATURES.
355 * Do it _after_ do_special() restored device parameters.
357 if (drive->current_speed == 0xff)
358 ide_config_drive_speed(drive, drive->desired_speed);
360 if (rq->cmd_type == REQ_TYPE_ATA_TASKFILE)
361 return execute_drive_cmd(drive, rq);
362 else if (blk_pm_request(rq)) {
363 struct request_pm_state *pm = rq->special;
365 printk("%s: start_power_step(step: %d)\n",
366 drive->name, pm->pm_step);
368 startstop = ide_start_power_step(drive, rq);
369 if (startstop == ide_stopped &&
370 pm->pm_step == IDE_PM_COMPLETED)
371 ide_complete_pm_rq(drive, rq);
373 } else if (!rq->rq_disk && blk_special_request(rq))
375 * TODO: Once all ULDs have been modified to
376 * check for specific op codes rather than
377 * blindly accepting any special request, the
378 * check for ->rq_disk above may be replaced
379 * by a more suitable mechanism or even
382 return ide_special_rq(drive, rq);
384 drv = *(struct ide_driver **)rq->rq_disk->private_data;
386 return drv->do_request(drive, rq, rq->sector);
388 return do_special(drive);
390 ide_kill_rq(drive, rq);
395 * ide_stall_queue - pause an IDE device
396 * @drive: drive to stall
397 * @timeout: time to stall for (jiffies)
399 * ide_stall_queue() can be used by a drive to give excess bandwidth back
400 * to the port by sleeping for timeout jiffies.
403 void ide_stall_queue (ide_drive_t *drive, unsigned long timeout)
405 if (timeout > WAIT_WORSTCASE)
406 timeout = WAIT_WORSTCASE;
407 drive->sleep = timeout + jiffies;
408 drive->dev_flags |= IDE_DFLAG_SLEEPING;
410 EXPORT_SYMBOL(ide_stall_queue);
412 static inline int ide_lock_port(ide_hwif_t *hwif)
422 static inline void ide_unlock_port(ide_hwif_t *hwif)
427 static inline int ide_lock_host(struct ide_host *host, ide_hwif_t *hwif)
431 if (host->host_flags & IDE_HFLAG_SERIALIZE) {
432 rc = test_and_set_bit_lock(IDE_HOST_BUSY, &host->host_busy);
435 host->get_lock(ide_intr, hwif);
441 static inline void ide_unlock_host(struct ide_host *host)
443 if (host->host_flags & IDE_HFLAG_SERIALIZE) {
444 if (host->release_lock)
445 host->release_lock();
446 clear_bit_unlock(IDE_HOST_BUSY, &host->host_busy);
451 * Issue a new request to a device.
453 void do_ide_request(struct request_queue *q)
455 ide_drive_t *drive = q->queuedata;
456 ide_hwif_t *hwif = drive->hwif;
457 struct ide_host *host = hwif->host;
458 struct request *rq = NULL;
459 ide_startstop_t startstop;
462 * drive is doing pre-flush, ordered write, post-flush sequence. even
463 * though that is 3 requests, it must be seen as a single transaction.
464 * we must not preempt this drive until that is complete
466 if (blk_queue_flushing(q))
468 * small race where queue could get replugged during
469 * the 3-request flush cycle, just yank the plug since
470 * we want it to finish asap
474 spin_unlock_irq(q->queue_lock);
476 /* HLD do_request() callback might sleep, make sure it's okay */
479 if (ide_lock_host(host, hwif))
482 spin_lock_irq(&hwif->lock);
484 if (!ide_lock_port(hwif)) {
485 ide_hwif_t *prev_port;
487 prev_port = hwif->host->cur_port;
490 if (drive->dev_flags & IDE_DFLAG_SLEEPING &&
491 time_after(drive->sleep, jiffies)) {
492 ide_unlock_port(hwif);
496 if ((hwif->host->host_flags & IDE_HFLAG_SERIALIZE) &&
499 * set nIEN for previous port, drives in the
500 * quirk_list may not like intr setups/cleanups
502 if (prev_port && prev_port->cur_dev->quirk_list == 0)
503 prev_port->tp_ops->write_devctl(prev_port,
507 hwif->host->cur_port = hwif;
509 hwif->cur_dev = drive;
510 drive->dev_flags &= ~(IDE_DFLAG_SLEEPING | IDE_DFLAG_PARKED);
512 spin_unlock_irq(&hwif->lock);
513 spin_lock_irq(q->queue_lock);
515 * we know that the queue isn't empty, but this can happen
516 * if the q->prep_rq_fn() decides to kill a request
518 rq = elv_next_request(drive->queue);
519 spin_unlock_irq(q->queue_lock);
520 spin_lock_irq(&hwif->lock);
523 ide_unlock_port(hwif);
528 * Sanity: don't accept a request that isn't a PM request
529 * if we are currently power managed. This is very important as
530 * blk_stop_queue() doesn't prevent the elv_next_request()
531 * above to return us whatever is in the queue. Since we call
532 * ide_do_request() ourselves, we end up taking requests while
533 * the queue is blocked...
535 * We let requests forced at head of queue with ide-preempt
536 * though. I hope that doesn't happen too much, hopefully not
537 * unless the subdriver triggers such a thing in its own PM
540 if ((drive->dev_flags & IDE_DFLAG_BLOCKED) &&
541 blk_pm_request(rq) == 0 &&
542 (rq->cmd_flags & REQ_PREEMPT) == 0) {
543 /* there should be no pending command at this point */
544 ide_unlock_port(hwif);
550 spin_unlock_irq(&hwif->lock);
551 startstop = start_request(drive, rq);
552 spin_lock_irq(&hwif->lock);
554 if (startstop == ide_stopped)
559 spin_unlock_irq(&hwif->lock);
561 ide_unlock_host(host);
562 spin_lock_irq(q->queue_lock);
566 spin_unlock_irq(&hwif->lock);
567 ide_unlock_host(host);
569 spin_lock_irq(q->queue_lock);
571 if (!elv_queue_empty(q))
575 static void ide_plug_device(ide_drive_t *drive)
577 struct request_queue *q = drive->queue;
580 spin_lock_irqsave(q->queue_lock, flags);
581 if (!elv_queue_empty(q))
583 spin_unlock_irqrestore(q->queue_lock, flags);
586 static int drive_is_ready(ide_drive_t *drive)
588 ide_hwif_t *hwif = drive->hwif;
591 if (drive->waiting_for_dma)
592 return hwif->dma_ops->dma_test_irq(drive);
594 if (hwif->io_ports.ctl_addr &&
595 (hwif->host_flags & IDE_HFLAG_BROKEN_ALTSTATUS) == 0)
596 stat = hwif->tp_ops->read_altstatus(hwif);
598 /* Note: this may clear a pending IRQ!! */
599 stat = hwif->tp_ops->read_status(hwif);
602 /* drive busy: definitely not interrupting */
605 /* drive ready: *might* be interrupting */
610 * ide_timer_expiry - handle lack of an IDE interrupt
611 * @data: timer callback magic (hwif)
613 * An IDE command has timed out before the expected drive return
614 * occurred. At this point we attempt to clean up the current
615 * mess. If the current handler includes an expiry handler then
616 * we invoke the expiry handler, and providing it is happy the
617 * work is done. If that fails we apply generic recovery rules
618 * invoking the handler and checking the drive DMA status. We
619 * have an excessively incestuous relationship with the DMA
620 * logic that wants cleaning up.
623 void ide_timer_expiry (unsigned long data)
625 ide_hwif_t *hwif = (ide_hwif_t *)data;
626 ide_drive_t *uninitialized_var(drive);
627 ide_handler_t *handler;
632 spin_lock_irqsave(&hwif->lock, flags);
634 handler = hwif->handler;
636 if (handler == NULL || hwif->req_gen != hwif->req_gen_timer) {
638 * Either a marginal timeout occurred
639 * (got the interrupt just as timer expired),
640 * or we were "sleeping" to give other devices a chance.
641 * Either way, we don't really want to complain about anything.
644 ide_expiry_t *expiry = hwif->expiry;
645 ide_startstop_t startstop = ide_stopped;
647 drive = hwif->cur_dev;
650 wait = expiry(drive);
651 if (wait > 0) { /* continue */
653 hwif->timer.expires = jiffies + wait;
654 hwif->req_gen_timer = hwif->req_gen;
655 add_timer(&hwif->timer);
656 spin_unlock_irqrestore(&hwif->lock, flags);
660 hwif->handler = NULL;
663 * We need to simulate a real interrupt when invoking
664 * the handler() function, which means we need to
665 * globally mask the specific IRQ:
667 spin_unlock(&hwif->lock);
668 /* disable_irq_nosync ?? */
669 disable_irq(hwif->irq);
670 /* local CPU only, as if we were handling an interrupt */
673 startstop = handler(drive);
674 } else if (drive_is_ready(drive)) {
675 if (drive->waiting_for_dma)
676 hwif->dma_ops->dma_lost_irq(drive);
678 hwif->ack_intr(hwif);
679 printk(KERN_WARNING "%s: lost interrupt\n",
681 startstop = handler(drive);
683 if (drive->waiting_for_dma)
684 startstop = ide_dma_timeout_retry(drive, wait);
686 startstop = ide_error(drive, "irq timeout",
687 hwif->tp_ops->read_status(hwif));
689 spin_lock_irq(&hwif->lock);
690 enable_irq(hwif->irq);
691 if (startstop == ide_stopped) {
692 ide_unlock_port(hwif);
696 spin_unlock_irqrestore(&hwif->lock, flags);
699 ide_unlock_host(hwif->host);
700 ide_plug_device(drive);
705 * unexpected_intr - handle an unexpected IDE interrupt
706 * @irq: interrupt line
707 * @hwif: port being processed
709 * There's nothing really useful we can do with an unexpected interrupt,
710 * other than reading the status register (to clear it), and logging it.
711 * There should be no way that an irq can happen before we're ready for it,
712 * so we needn't worry much about losing an "important" interrupt here.
714 * On laptops (and "green" PCs), an unexpected interrupt occurs whenever
715 * the drive enters "idle", "standby", or "sleep" mode, so if the status
716 * looks "good", we just ignore the interrupt completely.
718 * This routine assumes __cli() is in effect when called.
720 * If an unexpected interrupt happens on irq15 while we are handling irq14
721 * and if the two interfaces are "serialized" (CMD640), then it looks like
722 * we could screw up by interfering with a new request being set up for
725 * In reality, this is a non-issue. The new command is not sent unless
726 * the drive is ready to accept one, in which case we know the drive is
727 * not trying to interrupt us. And ide_set_handler() is always invoked
728 * before completing the issuance of any new drive command, so we will not
729 * be accidentally invoked as a result of any valid command completion
733 static void unexpected_intr(int irq, ide_hwif_t *hwif)
735 u8 stat = hwif->tp_ops->read_status(hwif);
737 if (!OK_STAT(stat, ATA_DRDY, BAD_STAT)) {
738 /* Try to not flood the console with msgs */
739 static unsigned long last_msgtime, count;
742 if (time_after(jiffies, last_msgtime + HZ)) {
743 last_msgtime = jiffies;
744 printk(KERN_ERR "%s: unexpected interrupt, "
745 "status=0x%02x, count=%ld\n",
746 hwif->name, stat, count);
752 * ide_intr - default IDE interrupt handler
753 * @irq: interrupt number
755 * @regs: unused weirdness from the kernel irq layer
757 * This is the default IRQ handler for the IDE layer. You should
758 * not need to override it. If you do be aware it is subtle in
761 * hwif is the interface in the group currently performing
762 * a command. hwif->cur_dev is the drive and hwif->handler is
763 * the IRQ handler to call. As we issue a command the handlers
764 * step through multiple states, reassigning the handler to the
765 * next step in the process. Unlike a smart SCSI controller IDE
766 * expects the main processor to sequence the various transfer
767 * stages. We also manage a poll timer to catch up with most
768 * timeout situations. There are still a few where the handlers
769 * don't ever decide to give up.
771 * The handler eventually returns ide_stopped to indicate the
772 * request completed. At this point we issue the next request
773 * on the port and the process begins again.
776 irqreturn_t ide_intr (int irq, void *dev_id)
778 ide_hwif_t *hwif = (ide_hwif_t *)dev_id;
779 struct ide_host *host = hwif->host;
780 ide_drive_t *uninitialized_var(drive);
781 ide_handler_t *handler;
783 ide_startstop_t startstop;
784 irqreturn_t irq_ret = IRQ_NONE;
787 if (host->host_flags & IDE_HFLAG_SERIALIZE) {
788 if (hwif != host->cur_port)
792 spin_lock_irqsave(&hwif->lock, flags);
794 if (hwif->ack_intr && hwif->ack_intr(hwif) == 0)
797 handler = hwif->handler;
799 if (handler == NULL || hwif->polling) {
801 * Not expecting an interrupt from this drive.
802 * That means this could be:
803 * (1) an interrupt from another PCI device
804 * sharing the same PCI INT# as us.
805 * or (2) a drive just entered sleep or standby mode,
806 * and is interrupting to let us know.
807 * or (3) a spurious interrupt of unknown origin.
809 * For PCI, we cannot tell the difference,
810 * so in that case we just ignore it and hope it goes away.
812 if ((host->irq_flags & IRQF_SHARED) == 0) {
814 * Probably not a shared PCI interrupt,
815 * so we can safely try to do something about it:
817 unexpected_intr(irq, hwif);
820 * Whack the status register, just in case
821 * we have a leftover pending IRQ.
823 (void)hwif->tp_ops->read_status(hwif);
828 drive = hwif->cur_dev;
830 if (!drive_is_ready(drive))
832 * This happens regularly when we share a PCI IRQ with
833 * another device. Unfortunately, it can also happen
834 * with some buggy drives that trigger the IRQ before
835 * their status register is up to date. Hopefully we have
836 * enough advance overhead that the latter isn't a problem.
840 hwif->handler = NULL;
843 del_timer(&hwif->timer);
844 spin_unlock(&hwif->lock);
846 if (hwif->port_ops && hwif->port_ops->clear_irq)
847 hwif->port_ops->clear_irq(drive);
849 if (drive->dev_flags & IDE_DFLAG_UNMASK)
850 local_irq_enable_in_hardirq();
852 /* service this interrupt, may set handler for next interrupt */
853 startstop = handler(drive);
855 spin_lock_irq(&hwif->lock);
857 * Note that handler() may have set things up for another
858 * interrupt to occur soon, but it cannot happen until
859 * we exit from this routine, because it will be the
860 * same irq as is currently being serviced here, and Linux
861 * won't allow another of the same (on any CPU) until we return.
863 if (startstop == ide_stopped) {
864 BUG_ON(hwif->handler);
865 ide_unlock_port(hwif);
868 irq_ret = IRQ_HANDLED;
870 spin_unlock_irqrestore(&hwif->lock, flags);
873 ide_unlock_host(hwif->host);
874 ide_plug_device(drive);
879 EXPORT_SYMBOL_GPL(ide_intr);
881 void ide_pad_transfer(ide_drive_t *drive, int write, int len)
883 ide_hwif_t *hwif = drive->hwif;
888 hwif->tp_ops->output_data(drive, NULL, buf, min(4, len));
890 hwif->tp_ops->input_data(drive, NULL, buf, min(4, len));
894 EXPORT_SYMBOL_GPL(ide_pad_transfer);