From a1317f714af7aed60ddc182d0122477cbe36ee9b Mon Sep 17 00:00:00 2001 From: Bartlomiej Zolnierkiewicz Date: Tue, 23 Jun 2009 23:52:17 -0700 Subject: ide: improve handling of Power Management requests Make hwif->rq point to PM request during PM sequence and do not allow any other types of requests to slip in (the old comment was never correct as there should be no such requests generated during PM sequence). Signed-off-by: Bartlomiej Zolnierkiewicz Signed-off-by: David S. Miller --- drivers/ide/ide-io.c | 54 +++++++++++++++++++++------------------------------- 1 file changed, 22 insertions(+), 32 deletions(-) (limited to 'drivers/ide') diff --git a/drivers/ide/ide-io.c b/drivers/ide/ide-io.c index 1059f809b809..93b7886a2d6e 100644 --- a/drivers/ide/ide-io.c +++ b/drivers/ide/ide-io.c @@ -476,10 +476,14 @@ void do_ide_request(struct request_queue *q) if (!ide_lock_port(hwif)) { ide_hwif_t *prev_port; - - WARN_ON_ONCE(hwif->rq); repeat: prev_port = hwif->host->cur_port; + + if (drive->dev_flags & IDE_DFLAG_BLOCKED) + rq = hwif->rq; + else + WARN_ON_ONCE(hwif->rq); + if (drive->dev_flags & IDE_DFLAG_SLEEPING && time_after(drive->sleep, jiffies)) { ide_unlock_port(hwif); @@ -506,43 +510,29 @@ repeat: hwif->cur_dev = drive; drive->dev_flags &= ~(IDE_DFLAG_SLEEPING | IDE_DFLAG_PARKED); - spin_unlock_irq(&hwif->lock); - spin_lock_irq(q->queue_lock); - /* - * we know that the queue isn't empty, but this can happen - * if the q->prep_rq_fn() decides to kill a request - */ - if (!rq) + if (rq == NULL) { + spin_unlock_irq(&hwif->lock); + spin_lock_irq(q->queue_lock); + /* + * we know that the queue isn't empty, but this can + * happen if ->prep_rq_fn() decides to kill a request + */ rq = blk_fetch_request(drive->queue); + spin_unlock_irq(q->queue_lock); + spin_lock_irq(&hwif->lock); - spin_unlock_irq(q->queue_lock); - spin_lock_irq(&hwif->lock); - - if (!rq) { - ide_unlock_port(hwif); - goto out; + if (rq == NULL) { + ide_unlock_port(hwif); + goto out; + } } /* * Sanity: don't accept a request that isn't a PM request - * if we are currently power managed. This is very important as - * blk_stop_queue() doesn't prevent the blk_fetch_request() - * above to return us whatever is in the queue. Since we call - * ide_do_request() ourselves, we end up taking requests while - * the queue is blocked... - * - * We let requests forced at head of queue with ide-preempt - * though. I hope that doesn't happen too much, hopefully not - * unless the subdriver triggers such a thing in its own PM - * state machine. + * if we are currently power managed. */ - if ((drive->dev_flags & IDE_DFLAG_BLOCKED) && - blk_pm_request(rq) == 0 && - (rq->cmd_flags & REQ_PREEMPT) == 0) { - /* there should be no pending command at this point */ - ide_unlock_port(hwif); - goto plug_device; - } + BUG_ON((drive->dev_flags & IDE_DFLAG_BLOCKED) && + blk_pm_request(rq) == 0); hwif->rq = rq; -- cgit v1.2.3-59-g8ed1b