diff options
authorKrzysztof Kozlowski <k.kozlowski@samsung.com>2015-06-10 17:17:07 +0900
committerVinod Koul <vinod.koul@intel.com>2015-06-12 15:22:26 +0530
commit88d04643c66052a1cf92a6fd5f92dff0f7757f61 (patch)
parent765c37d876698268eea8b820081ac8fc9d0fc8bc (diff)
dmaengine: Fix choppy sound because of unimplemented resume
Some drivers implement only pause operation (no resuming). Example is pl330 where pause is needed for getting residuum. pl330 does not support resume operation, transfer must be stopped after pause. However for slaves this is exposed always as "pause and resume" which introduces subtle errors on Odroid U3 board (Exynos4412 with pl330). After adding pause function to pl330 driver the audio playback (utilizing DMA) gets choppy after some time (approximately 24 hours). Fix this by exposing "cmd_pause" if and only if pause and resume are implemented. Signed-off-by: Krzysztof Kozlowski <k.kozlowski@samsung.com> Reported-by: gabriel@unseen.is Reported-by: Marek Szyprowski <m.szyprowski@samsung.com> Cc: <stable@vger.kernel.org> Fixes: 88987d2c7534 ("dmaengine: pl330: add DMA_PAUSE feature") Acked-by: Maxime Ripard <maxime.ripard@free-electrons.com> Signed-off-by: Vinod Koul <vinod.koul@intel.com>
1 files changed, 5 insertions, 1 deletions
diff --git a/drivers/dma/dmaengine.c b/drivers/dma/dmaengine.c
index 2890d744bb1b..3ddfd1f6c23c 100644
--- a/drivers/dma/dmaengine.c
+++ b/drivers/dma/dmaengine.c
@@ -487,7 +487,11 @@ int dma_get_slave_caps(struct dma_chan *chan, struct dma_slave_caps *caps)
caps->directions = device->directions;
caps->residue_granularity = device->residue_granularity;
- caps->cmd_pause = !!device->device_pause;
+ /*
+ * Some devices implement only pause (e.g. to get residuum) but no
+ * resume. However cmd_pause is advertised as pause AND resume.
+ */
+ caps->cmd_pause = !!(device->device_pause && device->device_resume);
caps->cmd_terminate = !!device->device_terminate_all;
return 0;