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Commit 8ae62993 authored by Yasir Malik's avatar Yasir Malik Committed by Gerrit - the friendly Code Review server
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crypto: msm: qce50: Prevent deadlock during timeout 



Lock out interrupts during issuing dummy request in timeout to prevent from
a potential deadlock happening.

Change-Id: I986d8c36c839a1dee23761465ad331ffc31dd6ac
CRs-Fixed: 1008319
Acked-by: default avatarChe-Min Hsieh <cheminh@qti.qualcomm.com>
Signed-off-by: default avatarYasir Malik <ymalik@codeaurora.org>
parent 4a91ea36

drivers/crypto/msm/qce50.c

+17 −4
Original line number Diff line number Diff line
@@ -3023,6 +3023,7 @@ static void qce_multireq_timeout(unsigned long data) 
	struct qce_device *pce_dev = (struct qce_device *)data;

	int ret = 0;

	int last_seq;

	unsigned long flags;



	last_seq = atomic_read(&pce_dev->bunch_cmd_seq);

	if (last_seq == 0 ||
@@ -3032,21 +3033,33 @@ static void qce_multireq_timeout(unsigned long data) 
		return;

	}

	/* last bunch mode command time out */



	/*

	 * From here to dummy request finish sps request and set owner back

	 * to none, we disable interrupt.

	 * So it won't get preempted or interrupted. If bam inerrupts happen

	 * between, and completion callback gets called from BAM, a new

	 * request may be issued by the client driver.  Deadlock may happen.

	 */

	local_irq_save(flags);

	if (cmpxchg(&pce_dev->owner, QCE_OWNER_NONE, QCE_OWNER_TIMEOUT)

							!= QCE_OWNER_NONE) {

		local_irq_restore(flags);

		mod_timer(&(pce_dev->timer), (jiffies + DELAY_IN_JIFFIES));

		return;

	}

	del_timer(&(pce_dev->timer));

	pce_dev->mode = IN_INTERRUPT_MODE;

	pce_dev->qce_stats.no_of_timeouts++;

	pr_debug("pcedev %d mode switch to INTR\n", pce_dev->dev_no);



	ret = qce_dummy_req(pce_dev);

	if (ret)

		pr_warn("pcedev %d: Failed to insert dummy req\n",

				pce_dev->dev_no);

	cmpxchg(&pce_dev->owner, QCE_OWNER_TIMEOUT, QCE_OWNER_NONE);

	pce_dev->mode = IN_INTERRUPT_MODE;

	local_irq_restore(flags);



	del_timer(&(pce_dev->timer));

	pce_dev->qce_stats.no_of_timeouts++;

	pr_debug("pcedev %d mode switch to INTR\n", pce_dev->dev_no);

}



void qce_get_driver_stats(void *handle)