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IDE: Make taskfile interface more robust wrt unexpected end-of-command

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Now that we handle all the special commands using REQ_TYPE_ATA_TASKFILE
rather than using the old REQ_TYPE_ATA_CMD model, we need to also
emulate the lack of full taskfile data that comes with the old command
model (ie when commands are generated with the HDIO_DRIVE_CMD ioctl
rather than using the HDIO_DRIVE_TASK[FILE] ioctls).

In particular, this means that we should handle command completion the
more relaxed way that the old drive_cmd_intr() code did.  It allows
commands to finish early even if they don't use up all the data that we
thought we had for them.

This fixes a regression seen by Anders Eriksson where some SMART
commands sent by smartd would cause a boot-time system hang on his
machine because the IDE command handling code didn't realize that the
command had completed.

Tested-by: Anders Eriksson <aeriksson@fastmail.fm>
Cc: Jens Axboe <jens.axboe@oracle.com>
Cc: Ingo Molnar <mingo@elte.hu>
Acked-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
Linus Torvalds 2008-03-18 21:26:24 -07:00
parent d5eee40572
commit 6c3c3158a8
1 changed files with 27 additions and 9 deletions
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36
drivers/ide/ide-taskfile.c
View file

@ -422,6 +422,25 @@ void task_end_request(ide_drive_t *drive, struct request *rq, u8 stat)
ide_end_request(drive, 1, rq->nr_sectors);
}
/*
* We got an interrupt on a task_in case, but no errors and no DRQ.
*
* It might be a spurious irq (shared irq), but it might be a
* command that had no output.
*/
static ide_startstop_t task_in_unexpected(ide_drive_t *drive, struct request *rq, u8 stat)
{
/* Command all done? */
if (OK_STAT(stat, READY_STAT, BUSY_STAT)) {
task_end_request(drive, rq, stat);
return ide_stopped;
}
/* Assume it was a spurious irq */
ide_set_handler(drive, &task_in_intr, WAIT_WORSTCASE, NULL);
return ide_started;
}
/*
* Handler for command with PIO data-in phase (Read/Read Multiple).
*/
@ -431,18 +450,17 @@ static ide_startstop_t task_in_intr(ide_drive_t *drive)
struct request *rq = HWGROUP(drive)->rq;
u8 stat = ide_read_status(drive);
/* new way for dealing with premature shared PCI interrupts */
if (!OK_STAT(stat, DRQ_STAT, BAD_R_STAT)) {
if (stat & (ERR_STAT | DRQ_STAT))
return task_error(drive, rq, __FUNCTION__, stat);
/* No data yet, so wait for another IRQ. */
ide_set_handler(drive, &task_in_intr, WAIT_WORSTCASE, NULL);
return ide_started;
}
/* Error? */
if (stat & ERR_STAT)
return task_error(drive, rq, __FUNCTION__, stat);
/* Didn't want any data? Odd. */
if (!(stat & DRQ_STAT))
return task_in_unexpected(drive, rq, stat);
ide_pio_datablock(drive, rq, 0);
/* If it was the last datablock check status and finish transfer. */
/* Are we done? Check status and finish transfer. */
if (!hwif->nleft) {
stat = wait_drive_not_busy(drive);
if (!OK_STAT(stat, 0, BAD_STAT))