From 2cd6bf6748f28008a1650dca57a8f14b27283803 Mon Sep 17 00:00:00 2001 From: Jassi Brar Date: Tue, 31 Mar 2015 10:21:14 +0530 Subject: [PATCH 2/2] dma: pl330: fix race between trigger and completion We need to hold the lock on channel in ISR to prevent it racing against the trigger call on the channel. Reported-by: Scott Branden Signed-off-by: Jassi Brar --- drivers/dma/pl330.c | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-) diff --git a/drivers/dma/pl330.c b/drivers/dma/pl330.c index d1f777e..ce40677 100644 --- a/drivers/dma/pl330.c +++ b/drivers/dma/pl330.c @@ -1573,6 +1573,7 @@ static int pl330_update(struct pl330_dmac *pl330) if (val & (1 << ev)) { /* Event occurred */ struct pl330_thread *thrd; u32 inten = readl(regs + INTEN); + unsigned long flag; int active; /* Clear the event */ @@ -1584,10 +1585,13 @@ static int pl330_update(struct pl330_dmac *pl330) id = pl330->events[ev]; thrd = &pl330->channels[id]; + spin_lock_irqsave(&thrd->pch->lock, flag); active = thrd->req_running; - if (active == -1) /* Aborted */ + if (active == -1) { /* Aborted */ + spin_unlock_irqrestore(&thrd->pch->lock, flag); continue; + } /* Detach the req */ descdone = thrd->req[active].desc; @@ -1600,6 +1604,7 @@ static int pl330_update(struct pl330_dmac *pl330) /* For now, just make a list of callbacks to be done */ list_add_tail(&descdone->rqd, &pl330->req_done); + spin_unlock_irqrestore(&thrd->pch->lock, flag); } } -- 1.9.1