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/hdreg.h>
44 #include <linux/completion.h>
45 #include <linux/reboot.h>
46 #include <linux/cdrom.h>
47 #include <linux/seq_file.h>
48 #include <linux/device.h>
49 #include <linux/kmod.h>
50 #include <linux/scatterlist.h>
51 #include <linux/bitops.h>
53 #include <asm/byteorder.h>
55 #include <asm/uaccess.h>
58 static int __ide_end_request(ide_drive_t *drive, struct request *rq,
59 int uptodate, unsigned int nr_bytes, int dequeue)
65 error = uptodate ? uptodate : -EIO;
68 * if failfast is set on a request, override number of sectors and
69 * complete the whole request right now
71 if (blk_noretry_request(rq) && error)
72 nr_bytes = rq->hard_nr_sectors << 9;
74 if (!blk_fs_request(rq) && error && !rq->errors)
78 * decide whether to reenable DMA -- 3 is a random magic for now,
79 * if we DMA timeout more than 3 times, just stay in PIO
81 if ((drive->dev_flags & IDE_DFLAG_DMA_PIO_RETRY) &&
82 drive->retry_pio <= 3) {
83 drive->dev_flags &= ~IDE_DFLAG_DMA_PIO_RETRY;
87 if (!blk_end_request(rq, error, nr_bytes))
90 if (ret == 0 && dequeue)
91 drive->hwif->rq = NULL;
97 * ide_end_request - complete an IDE I/O
98 * @drive: IDE device for the I/O
100 * @nr_sectors: number of sectors completed
102 * This is our end_request wrapper function. We complete the I/O
103 * update random number input and dequeue the request, which if
104 * it was tagged may be out of order.
107 int ide_end_request (ide_drive_t *drive, int uptodate, int nr_sectors)
109 unsigned int nr_bytes = nr_sectors << 9;
110 struct request *rq = drive->hwif->rq;
113 if (blk_pc_request(rq))
114 nr_bytes = rq->data_len;
116 nr_bytes = rq->hard_cur_sectors << 9;
119 return __ide_end_request(drive, rq, uptodate, nr_bytes, 1);
121 EXPORT_SYMBOL(ide_end_request);
124 * ide_end_dequeued_request - complete an IDE I/O
125 * @drive: IDE device for the I/O
127 * @nr_sectors: number of sectors completed
129 * Complete an I/O that is no longer on the request queue. This
130 * typically occurs when we pull the request and issue a REQUEST_SENSE.
131 * We must still finish the old request but we must not tamper with the
132 * queue in the meantime.
134 * NOTE: This path does not handle barrier, but barrier is not supported
138 int ide_end_dequeued_request(ide_drive_t *drive, struct request *rq,
139 int uptodate, int nr_sectors)
141 BUG_ON(!blk_rq_started(rq));
143 return __ide_end_request(drive, rq, uptodate, nr_sectors << 9, 0);
145 EXPORT_SYMBOL_GPL(ide_end_dequeued_request);
147 void ide_complete_cmd(ide_drive_t *drive, struct ide_cmd *cmd, u8 stat, u8 err)
149 struct ide_taskfile *tf = &cmd->tf;
150 struct request *rq = cmd->rq;
155 drive->hwif->tp_ops->tf_read(drive, cmd);
157 if (rq && rq->cmd_type == REQ_TYPE_ATA_TASKFILE)
158 memcpy(rq->special, cmd, sizeof(*cmd));
160 if (cmd->tf_flags & IDE_TFLAG_DYN)
164 void ide_complete_rq(ide_drive_t *drive, u8 err)
166 ide_hwif_t *hwif = drive->hwif;
167 struct request *rq = hwif->rq;
173 if (unlikely(blk_end_request(rq, (rq->errors ? -EIO : 0),
177 EXPORT_SYMBOL(ide_complete_rq);
179 void ide_kill_rq(ide_drive_t *drive, struct request *rq)
181 u8 drv_req = blk_special_request(rq) && rq->rq_disk;
182 u8 media = drive->media;
184 drive->failed_pc = NULL;
186 if ((media == ide_floppy && drv_req) || media == ide_tape)
187 rq->errors = IDE_DRV_ERROR_GENERAL;
189 if ((media == ide_floppy || media == ide_tape) && drv_req)
190 ide_complete_rq(drive, 0);
192 ide_end_request(drive, 0, 0);
195 static void ide_tf_set_specify_cmd(ide_drive_t *drive, struct ide_taskfile *tf)
197 tf->nsect = drive->sect;
198 tf->lbal = drive->sect;
199 tf->lbam = drive->cyl;
200 tf->lbah = drive->cyl >> 8;
201 tf->device = (drive->head - 1) | drive->select;
202 tf->command = ATA_CMD_INIT_DEV_PARAMS;
205 static void ide_tf_set_restore_cmd(ide_drive_t *drive, struct ide_taskfile *tf)
207 tf->nsect = drive->sect;
208 tf->command = ATA_CMD_RESTORE;
211 static void ide_tf_set_setmult_cmd(ide_drive_t *drive, struct ide_taskfile *tf)
213 tf->nsect = drive->mult_req;
214 tf->command = ATA_CMD_SET_MULTI;
217 static ide_startstop_t ide_disk_special(ide_drive_t *drive)
219 special_t *s = &drive->special;
222 memset(&cmd, 0, sizeof(cmd));
223 cmd.data_phase = TASKFILE_NO_DATA;
225 if (s->b.set_geometry) {
226 s->b.set_geometry = 0;
227 ide_tf_set_specify_cmd(drive, &cmd.tf);
228 } else if (s->b.recalibrate) {
229 s->b.recalibrate = 0;
230 ide_tf_set_restore_cmd(drive, &cmd.tf);
231 } else if (s->b.set_multmode) {
232 s->b.set_multmode = 0;
233 ide_tf_set_setmult_cmd(drive, &cmd.tf);
235 int special = s->all;
237 printk(KERN_ERR "%s: bad special flag: 0x%02x\n", drive->name, special);
241 cmd.tf_flags = IDE_TFLAG_TF | IDE_TFLAG_DEVICE |
242 IDE_TFLAG_CUSTOM_HANDLER;
244 do_rw_taskfile(drive, &cmd);
250 * do_special - issue some special commands
251 * @drive: drive the command is for
253 * do_special() is used to issue ATA_CMD_INIT_DEV_PARAMS,
254 * ATA_CMD_RESTORE and ATA_CMD_SET_MULTI commands to a drive.
256 * It used to do much more, but has been scaled back.
259 static ide_startstop_t do_special (ide_drive_t *drive)
261 special_t *s = &drive->special;
264 printk("%s: do_special: 0x%02x\n", drive->name, s->all);
266 if (drive->media == ide_disk)
267 return ide_disk_special(drive);
274 void ide_map_sg(ide_drive_t *drive, struct request *rq)
276 ide_hwif_t *hwif = drive->hwif;
277 struct scatterlist *sg = hwif->sg_table;
279 if (rq->cmd_type == REQ_TYPE_ATA_TASKFILE) {
280 sg_init_one(sg, rq->buffer, rq->nr_sectors * SECTOR_SIZE);
282 } else if (!rq->bio) {
283 sg_init_one(sg, rq->data, rq->data_len);
286 hwif->sg_nents = blk_rq_map_sg(drive->queue, rq, sg);
290 EXPORT_SYMBOL_GPL(ide_map_sg);
292 void ide_init_sg_cmd(ide_drive_t *drive, struct request *rq)
294 ide_hwif_t *hwif = drive->hwif;
296 hwif->nsect = hwif->nleft = rq->nr_sectors;
301 EXPORT_SYMBOL_GPL(ide_init_sg_cmd);
304 * execute_drive_command - issue special drive command
305 * @drive: the drive to issue the command on
306 * @rq: the request structure holding the command
308 * execute_drive_cmd() issues a special drive command, usually
309 * initiated by ioctl() from the external hdparm program. The
310 * command can be a drive command, drive task or taskfile
311 * operation. Weirdly you can call it with NULL to wait for
312 * all commands to finish. Don't do this as that is due to change
315 static ide_startstop_t execute_drive_cmd (ide_drive_t *drive,
318 struct ide_cmd *cmd = rq->special;
321 switch (cmd->data_phase) {
322 case TASKFILE_MULTI_OUT:
324 case TASKFILE_MULTI_IN:
326 ide_init_sg_cmd(drive, rq);
327 ide_map_sg(drive, rq);
332 return do_rw_taskfile(drive, cmd);
336 * NULL is actually a valid way of waiting for
337 * all current requests to be flushed from the queue.
340 printk("%s: DRIVE_CMD (null)\n", drive->name);
342 ide_complete_rq(drive, 0);
347 static ide_startstop_t ide_special_rq(ide_drive_t *drive, struct request *rq)
353 case REQ_UNPARK_HEADS:
354 return ide_do_park_unpark(drive, rq);
355 case REQ_DEVSET_EXEC:
356 return ide_do_devset(drive, rq);
357 case REQ_DRIVE_RESET:
358 return ide_do_reset(drive);
360 blk_dump_rq_flags(rq, "ide_special_rq - bad request");
361 ide_end_request(drive, 0, 0);
367 * start_request - start of I/O and command issuing for IDE
369 * start_request() initiates handling of a new I/O request. It
370 * accepts commands and I/O (read/write) requests.
372 * FIXME: this function needs a rename
375 static ide_startstop_t start_request (ide_drive_t *drive, struct request *rq)
377 ide_startstop_t startstop;
379 BUG_ON(!blk_rq_started(rq));
382 printk("%s: start_request: current=0x%08lx\n",
383 drive->hwif->name, (unsigned long) rq);
386 /* bail early if we've exceeded max_failures */
387 if (drive->max_failures && (drive->failures > drive->max_failures)) {
388 rq->cmd_flags |= REQ_FAILED;
392 if (blk_pm_request(rq))
393 ide_check_pm_state(drive, rq);
396 if (ide_wait_stat(&startstop, drive, drive->ready_stat,
397 ATA_BUSY | ATA_DRQ, WAIT_READY)) {
398 printk(KERN_ERR "%s: drive not ready for command\n", drive->name);
401 if (!drive->special.all) {
402 struct ide_driver *drv;
405 * We reset the drive so we need to issue a SETFEATURES.
406 * Do it _after_ do_special() restored device parameters.
408 if (drive->current_speed == 0xff)
409 ide_config_drive_speed(drive, drive->desired_speed);
411 if (rq->cmd_type == REQ_TYPE_ATA_TASKFILE)
412 return execute_drive_cmd(drive, rq);
413 else if (blk_pm_request(rq)) {
414 struct request_pm_state *pm = rq->data;
416 printk("%s: start_power_step(step: %d)\n",
417 drive->name, pm->pm_step);
419 startstop = ide_start_power_step(drive, rq);
420 if (startstop == ide_stopped &&
421 pm->pm_step == IDE_PM_COMPLETED)
422 ide_complete_pm_rq(drive, rq);
424 } else if (!rq->rq_disk && blk_special_request(rq))
426 * TODO: Once all ULDs have been modified to
427 * check for specific op codes rather than
428 * blindly accepting any special request, the
429 * check for ->rq_disk above may be replaced
430 * by a more suitable mechanism or even
433 return ide_special_rq(drive, rq);
435 drv = *(struct ide_driver **)rq->rq_disk->private_data;
437 return drv->do_request(drive, rq, rq->sector);
439 return do_special(drive);
441 ide_kill_rq(drive, rq);
446 * ide_stall_queue - pause an IDE device
447 * @drive: drive to stall
448 * @timeout: time to stall for (jiffies)
450 * ide_stall_queue() can be used by a drive to give excess bandwidth back
451 * to the port by sleeping for timeout jiffies.
454 void ide_stall_queue (ide_drive_t *drive, unsigned long timeout)
456 if (timeout > WAIT_WORSTCASE)
457 timeout = WAIT_WORSTCASE;
458 drive->sleep = timeout + jiffies;
459 drive->dev_flags |= IDE_DFLAG_SLEEPING;
461 EXPORT_SYMBOL(ide_stall_queue);
463 static inline int ide_lock_port(ide_hwif_t *hwif)
473 static inline void ide_unlock_port(ide_hwif_t *hwif)
478 static inline int ide_lock_host(struct ide_host *host, ide_hwif_t *hwif)
482 if (host->host_flags & IDE_HFLAG_SERIALIZE) {
483 rc = test_and_set_bit_lock(IDE_HOST_BUSY, &host->host_busy);
486 host->get_lock(ide_intr, hwif);
492 static inline void ide_unlock_host(struct ide_host *host)
494 if (host->host_flags & IDE_HFLAG_SERIALIZE) {
495 if (host->release_lock)
496 host->release_lock();
497 clear_bit_unlock(IDE_HOST_BUSY, &host->host_busy);
502 * Issue a new request to a device.
504 void do_ide_request(struct request_queue *q)
506 ide_drive_t *drive = q->queuedata;
507 ide_hwif_t *hwif = drive->hwif;
508 struct ide_host *host = hwif->host;
509 struct request *rq = NULL;
510 ide_startstop_t startstop;
513 * drive is doing pre-flush, ordered write, post-flush sequence. even
514 * though that is 3 requests, it must be seen as a single transaction.
515 * we must not preempt this drive until that is complete
517 if (blk_queue_flushing(q))
519 * small race where queue could get replugged during
520 * the 3-request flush cycle, just yank the plug since
521 * we want it to finish asap
525 spin_unlock_irq(q->queue_lock);
527 if (ide_lock_host(host, hwif))
530 spin_lock_irq(&hwif->lock);
532 if (!ide_lock_port(hwif)) {
533 ide_hwif_t *prev_port;
535 prev_port = hwif->host->cur_port;
538 if (drive->dev_flags & IDE_DFLAG_SLEEPING) {
539 if (time_before(drive->sleep, jiffies)) {
540 ide_unlock_port(hwif);
545 if ((hwif->host->host_flags & IDE_HFLAG_SERIALIZE) &&
548 * set nIEN for previous port, drives in the
549 * quirk_list may not like intr setups/cleanups
551 if (prev_port && prev_port->cur_dev->quirk_list == 0)
552 prev_port->tp_ops->set_irq(prev_port, 0);
554 hwif->host->cur_port = hwif;
556 hwif->cur_dev = drive;
557 drive->dev_flags &= ~(IDE_DFLAG_SLEEPING | IDE_DFLAG_PARKED);
559 spin_unlock_irq(&hwif->lock);
560 spin_lock_irq(q->queue_lock);
562 * we know that the queue isn't empty, but this can happen
563 * if the q->prep_rq_fn() decides to kill a request
565 rq = elv_next_request(drive->queue);
566 spin_unlock_irq(q->queue_lock);
567 spin_lock_irq(&hwif->lock);
570 ide_unlock_port(hwif);
575 * Sanity: don't accept a request that isn't a PM request
576 * if we are currently power managed. This is very important as
577 * blk_stop_queue() doesn't prevent the elv_next_request()
578 * above to return us whatever is in the queue. Since we call
579 * ide_do_request() ourselves, we end up taking requests while
580 * the queue is blocked...
582 * We let requests forced at head of queue with ide-preempt
583 * though. I hope that doesn't happen too much, hopefully not
584 * unless the subdriver triggers such a thing in its own PM
587 if ((drive->dev_flags & IDE_DFLAG_BLOCKED) &&
588 blk_pm_request(rq) == 0 &&
589 (rq->cmd_flags & REQ_PREEMPT) == 0) {
590 /* there should be no pending command at this point */
591 ide_unlock_port(hwif);
597 spin_unlock_irq(&hwif->lock);
598 startstop = start_request(drive, rq);
599 spin_lock_irq(&hwif->lock);
601 if (startstop == ide_stopped)
606 spin_unlock_irq(&hwif->lock);
608 ide_unlock_host(host);
609 spin_lock_irq(q->queue_lock);
613 spin_unlock_irq(&hwif->lock);
614 ide_unlock_host(host);
616 spin_lock_irq(q->queue_lock);
618 if (!elv_queue_empty(q))
622 static void ide_plug_device(ide_drive_t *drive)
624 struct request_queue *q = drive->queue;
627 spin_lock_irqsave(q->queue_lock, flags);
628 if (!elv_queue_empty(q))
630 spin_unlock_irqrestore(q->queue_lock, flags);
633 static int drive_is_ready(ide_drive_t *drive)
635 ide_hwif_t *hwif = drive->hwif;
638 if (drive->waiting_for_dma)
639 return hwif->dma_ops->dma_test_irq(drive);
641 if (hwif->io_ports.ctl_addr &&
642 (hwif->host_flags & IDE_HFLAG_BROKEN_ALTSTATUS) == 0)
643 stat = hwif->tp_ops->read_altstatus(hwif);
645 /* Note: this may clear a pending IRQ!! */
646 stat = hwif->tp_ops->read_status(hwif);
649 /* drive busy: definitely not interrupting */
652 /* drive ready: *might* be interrupting */
657 * ide_timer_expiry - handle lack of an IDE interrupt
658 * @data: timer callback magic (hwif)
660 * An IDE command has timed out before the expected drive return
661 * occurred. At this point we attempt to clean up the current
662 * mess. If the current handler includes an expiry handler then
663 * we invoke the expiry handler, and providing it is happy the
664 * work is done. If that fails we apply generic recovery rules
665 * invoking the handler and checking the drive DMA status. We
666 * have an excessively incestuous relationship with the DMA
667 * logic that wants cleaning up.
670 void ide_timer_expiry (unsigned long data)
672 ide_hwif_t *hwif = (ide_hwif_t *)data;
673 ide_drive_t *uninitialized_var(drive);
674 ide_handler_t *handler;
679 spin_lock_irqsave(&hwif->lock, flags);
681 handler = hwif->handler;
683 if (handler == NULL || hwif->req_gen != hwif->req_gen_timer) {
685 * Either a marginal timeout occurred
686 * (got the interrupt just as timer expired),
687 * or we were "sleeping" to give other devices a chance.
688 * Either way, we don't really want to complain about anything.
691 ide_expiry_t *expiry = hwif->expiry;
692 ide_startstop_t startstop = ide_stopped;
694 drive = hwif->cur_dev;
697 wait = expiry(drive);
698 if (wait > 0) { /* continue */
700 hwif->timer.expires = jiffies + wait;
701 hwif->req_gen_timer = hwif->req_gen;
702 add_timer(&hwif->timer);
703 spin_unlock_irqrestore(&hwif->lock, flags);
707 hwif->handler = NULL;
709 * We need to simulate a real interrupt when invoking
710 * the handler() function, which means we need to
711 * globally mask the specific IRQ:
713 spin_unlock(&hwif->lock);
714 /* disable_irq_nosync ?? */
715 disable_irq(hwif->irq);
716 /* local CPU only, as if we were handling an interrupt */
719 startstop = handler(drive);
720 } else if (drive_is_ready(drive)) {
721 if (drive->waiting_for_dma)
722 hwif->dma_ops->dma_lost_irq(drive);
724 hwif->ack_intr(hwif);
725 printk(KERN_WARNING "%s: lost interrupt\n",
727 startstop = handler(drive);
729 if (drive->waiting_for_dma)
730 startstop = ide_dma_timeout_retry(drive, wait);
732 startstop = ide_error(drive, "irq timeout",
733 hwif->tp_ops->read_status(hwif));
735 spin_lock_irq(&hwif->lock);
736 enable_irq(hwif->irq);
737 if (startstop == ide_stopped) {
738 ide_unlock_port(hwif);
742 spin_unlock_irqrestore(&hwif->lock, flags);
745 ide_unlock_host(hwif->host);
746 ide_plug_device(drive);
751 * unexpected_intr - handle an unexpected IDE interrupt
752 * @irq: interrupt line
753 * @hwif: port being processed
755 * There's nothing really useful we can do with an unexpected interrupt,
756 * other than reading the status register (to clear it), and logging it.
757 * There should be no way that an irq can happen before we're ready for it,
758 * so we needn't worry much about losing an "important" interrupt here.
760 * On laptops (and "green" PCs), an unexpected interrupt occurs whenever
761 * the drive enters "idle", "standby", or "sleep" mode, so if the status
762 * looks "good", we just ignore the interrupt completely.
764 * This routine assumes __cli() is in effect when called.
766 * If an unexpected interrupt happens on irq15 while we are handling irq14
767 * and if the two interfaces are "serialized" (CMD640), then it looks like
768 * we could screw up by interfering with a new request being set up for
771 * In reality, this is a non-issue. The new command is not sent unless
772 * the drive is ready to accept one, in which case we know the drive is
773 * not trying to interrupt us. And ide_set_handler() is always invoked
774 * before completing the issuance of any new drive command, so we will not
775 * be accidentally invoked as a result of any valid command completion
779 static void unexpected_intr(int irq, ide_hwif_t *hwif)
781 u8 stat = hwif->tp_ops->read_status(hwif);
783 if (!OK_STAT(stat, ATA_DRDY, BAD_STAT)) {
784 /* Try to not flood the console with msgs */
785 static unsigned long last_msgtime, count;
788 if (time_after(jiffies, last_msgtime + HZ)) {
789 last_msgtime = jiffies;
790 printk(KERN_ERR "%s: unexpected interrupt, "
791 "status=0x%02x, count=%ld\n",
792 hwif->name, stat, count);
798 * ide_intr - default IDE interrupt handler
799 * @irq: interrupt number
801 * @regs: unused weirdness from the kernel irq layer
803 * This is the default IRQ handler for the IDE layer. You should
804 * not need to override it. If you do be aware it is subtle in
807 * hwif is the interface in the group currently performing
808 * a command. hwif->cur_dev is the drive and hwif->handler is
809 * the IRQ handler to call. As we issue a command the handlers
810 * step through multiple states, reassigning the handler to the
811 * next step in the process. Unlike a smart SCSI controller IDE
812 * expects the main processor to sequence the various transfer
813 * stages. We also manage a poll timer to catch up with most
814 * timeout situations. There are still a few where the handlers
815 * don't ever decide to give up.
817 * The handler eventually returns ide_stopped to indicate the
818 * request completed. At this point we issue the next request
819 * on the port and the process begins again.
822 irqreturn_t ide_intr (int irq, void *dev_id)
824 ide_hwif_t *hwif = (ide_hwif_t *)dev_id;
825 struct ide_host *host = hwif->host;
826 ide_drive_t *uninitialized_var(drive);
827 ide_handler_t *handler;
829 ide_startstop_t startstop;
830 irqreturn_t irq_ret = IRQ_NONE;
833 if (host->host_flags & IDE_HFLAG_SERIALIZE) {
834 if (hwif != host->cur_port)
838 spin_lock_irqsave(&hwif->lock, flags);
840 if (hwif->ack_intr && hwif->ack_intr(hwif) == 0)
843 handler = hwif->handler;
845 if (handler == NULL || hwif->polling) {
847 * Not expecting an interrupt from this drive.
848 * That means this could be:
849 * (1) an interrupt from another PCI device
850 * sharing the same PCI INT# as us.
851 * or (2) a drive just entered sleep or standby mode,
852 * and is interrupting to let us know.
853 * or (3) a spurious interrupt of unknown origin.
855 * For PCI, we cannot tell the difference,
856 * so in that case we just ignore it and hope it goes away.
858 if ((host->irq_flags & IRQF_SHARED) == 0) {
860 * Probably not a shared PCI interrupt,
861 * so we can safely try to do something about it:
863 unexpected_intr(irq, hwif);
866 * Whack the status register, just in case
867 * we have a leftover pending IRQ.
869 (void)hwif->tp_ops->read_status(hwif);
874 drive = hwif->cur_dev;
876 if (!drive_is_ready(drive))
878 * This happens regularly when we share a PCI IRQ with
879 * another device. Unfortunately, it can also happen
880 * with some buggy drives that trigger the IRQ before
881 * their status register is up to date. Hopefully we have
882 * enough advance overhead that the latter isn't a problem.
886 hwif->handler = NULL;
888 del_timer(&hwif->timer);
889 spin_unlock(&hwif->lock);
891 if (hwif->port_ops && hwif->port_ops->clear_irq)
892 hwif->port_ops->clear_irq(drive);
894 if (drive->dev_flags & IDE_DFLAG_UNMASK)
895 local_irq_enable_in_hardirq();
897 /* service this interrupt, may set handler for next interrupt */
898 startstop = handler(drive);
900 spin_lock_irq(&hwif->lock);
902 * Note that handler() may have set things up for another
903 * interrupt to occur soon, but it cannot happen until
904 * we exit from this routine, because it will be the
905 * same irq as is currently being serviced here, and Linux
906 * won't allow another of the same (on any CPU) until we return.
908 if (startstop == ide_stopped) {
909 BUG_ON(hwif->handler);
910 ide_unlock_port(hwif);
913 irq_ret = IRQ_HANDLED;
915 spin_unlock_irqrestore(&hwif->lock, flags);
918 ide_unlock_host(hwif->host);
919 ide_plug_device(drive);
924 EXPORT_SYMBOL_GPL(ide_intr);
926 void ide_pad_transfer(ide_drive_t *drive, int write, int len)
928 ide_hwif_t *hwif = drive->hwif;
933 hwif->tp_ops->output_data(drive, NULL, buf, min(4, len));
935 hwif->tp_ops->input_data(drive, NULL, buf, min(4, len));
939 EXPORT_SYMBOL_GPL(ide_pad_transfer);