evie/android_kernel_oneplus_msm8998
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mmc: queue: fix for system suspend flow for eMMC command queue (cmdq)

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System suspend executed on kernel PM core context. When there are active
requests system suspend is rejected. Semaphore used to resolve race
between mmc_cmdq_thread() and mmc_queue_suspend().

Change-Id: I88f668d7a6dd6403407ac8208265e4439b35173c
Signed-off-by: Konstantin Dorfman <kdorfman@codeaurora.org>
This commit is contained in:
Konstantin Dorfman 2015-07-23 10:16:57 +03:00 • committed by Subhash Jadavani
parent 42dd0264d1
commit 2cfffa3bbe
1 changed files with 24 additions and 16 deletions
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40
drivers/mmc/card/queue.c
View file

@ -686,12 +686,6 @@ void mmc_cmdq_clean(struct mmc_queue *mq, struct mmc_card *card)
mq->mqrq_cmdq = NULL;
}
static void mmc_wait_for_pending_reqs(struct mmc_queue *mq)
{
wait_for_completion(&mq->cmdq_shutdown_complete);
mq->cmdq_shutdown(mq);
}
/**
* mmc_queue_suspend - suspend a MMC request queue
* @mq: MMC queue to suspend
@ -708,22 +702,36 @@ int mmc_queue_suspend(struct mmc_queue *mq, int wait)
int rc = 0;
struct mmc_card *card = mq->card;
if (card->cmdq_init && blk_queue_tagged(q) && wait) {
if (card->cmdq_init && blk_queue_tagged(q)) {
struct mmc_host *host = card->host;
spin_lock_irqsave(q->queue_lock, flags);
blk_stop_queue(q);
spin_unlock_irqrestore(q->queue_lock, flags);
/*
* Wait for already queued requests to be issued by
* mmc_cmdqd.
*/
down(&mq->thread_sem);
/* Wait for already issued requests to complete */
if (host->cmdq_ctx.active_reqs)
mmc_wait_for_pending_reqs(mq);
mq->cmdq_shutdown(mq);
if (wait) {
/*
* Wait for already queued requests to be issued by
* mmc_cmdqd.
*/
down(&mq->thread_sem);
/* Wait for already issued requests to complete */
if (host->cmdq_ctx.active_reqs)
wait_for_completion(
&mq->cmdq_shutdown_complete);
mq->cmdq_shutdown(mq);
} else if (!test_and_set_bit(MMC_QUEUE_SUSPENDED, &mq->flags)) {
rc = down_trylock(&mq->thread_sem);
if (rc || host->cmdq_ctx.active_reqs) {
clear_bit(MMC_QUEUE_SUSPENDED, &mq->flags);
spin_lock_irqsave(q->queue_lock, flags);
blk_start_queue(q);
spin_unlock_irqrestore(q->queue_lock, flags);
rc = -EBUSY;
}
}
goto out;
}