From 81cc6edc08705ac0146fe6ac14a0982a31ce6f3d Mon Sep 17 00:00:00 2001 From: Krzysztof Kozlowski Date: Thu, 21 May 2015 09:34:09 +0900 Subject: dmaengine: pl330: Fix hang on dmaengine_terminate_all on certain boards The pl330 device could hang infinitely on certain boards when DMA channels are terminated. It was caused by lack of runtime resume when executing pl330_terminate_all() which calls the _stop() function. _stop() accesses device register and can loop infinitely while checking for device state. The hang was confirmed by Dinh Nguyen on Altera SOCFPGA Cyclone V board during boot. It can be also triggered with: $ echo 1 > /sys/module/dmatest/parameters/iterations $ echo dma1chan0 > /sys/module/dmatest/parameters/channel $ echo 1 > /sys/module/dmatest/parameters/run $ sleep 1 $ cat /sys/module/dmatest/parameters/run Reported-by: Dinh Nguyen Signed-off-by: Krzysztof Kozlowski Fixes: ae43b3289186 ("ARM: 8202/1: dmaengine: pl330: Add runtime Power Management support v12") Cc: Tested-by: Dinh Nguyen Signed-off-by: Vinod Koul --- drivers/dma/pl330.c | 3 +++ 1 file changed, 3 insertions(+) (limited to 'drivers/dma') diff --git a/drivers/dma/pl330.c b/drivers/dma/pl330.c index a7d9d3029b14..340f9e607cd8 100644 --- a/drivers/dma/pl330.c +++ b/drivers/dma/pl330.c @@ -2127,6 +2127,7 @@ static int pl330_terminate_all(struct dma_chan *chan) struct pl330_dmac *pl330 = pch->dmac; LIST_HEAD(list); + pm_runtime_get_sync(pl330->ddma.dev); spin_lock_irqsave(&pch->lock, flags); spin_lock(&pl330->lock); _stop(pch->thread); @@ -2151,6 +2152,8 @@ static int pl330_terminate_all(struct dma_chan *chan) list_splice_tail_init(&pch->work_list, &pl330->desc_pool); list_splice_tail_init(&pch->completed_list, &pl330->desc_pool); spin_unlock_irqrestore(&pch->lock, flags); + pm_runtime_mark_last_busy(pl330->ddma.dev); + pm_runtime_put_autosuspend(pl330->ddma.dev); return 0; } -- cgit v1.2.3