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authorKrzysztof Kozlowski <k.kozlowski@samsung.com>2015-05-21 03:34:09 +0300
committerVinod Koul <vinod.koul@intel.com>2015-05-22 15:31:03 +0300
commit81cc6edc08705ac0146fe6ac14a0982a31ce6f3d (patch)
treea2f9eba6363f198527f5553aef5ed72a005c10fc /drivers/dma/pl330.c
parent5ebe6afaf0057ac3eaeb98defd5456894b446d22 (diff)
downloadlinux-81cc6edc08705ac0146fe6ac14a0982a31ce6f3d.tar.xz
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 <dinguyen@opensource.altera.com> Signed-off-by: Krzysztof Kozlowski <k.kozlowski@samsung.com> Fixes: ae43b3289186 ("ARM: 8202/1: dmaengine: pl330: Add runtime Power Management support v12") Cc: <stable@vger.kernel.org> Tested-by: Dinh Nguyen <dinguyen@opensource.altera.com> Signed-off-by: Vinod Koul <vinod.koul@intel.com>
Diffstat (limited to 'drivers/dma/pl330.c')
-rw-r--r--drivers/dma/pl330.c3
1 files changed, 3 insertions, 0 deletions
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;
}