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* [PATCH] dma: imx: correct sdmac->status for cyclic dma tx
@ 2014-05-15  1:22 jiada_wang at mentor.com
  2014-06-01 11:40 ` Vinod Koul
  0 siblings, 1 reply; 4+ messages in thread
From: jiada_wang at mentor.com @ 2014-05-15  1:22 UTC (permalink / raw)
  To: linux-arm-kernel

From: Jiada Wang <jiada_wang@mentor.com>

In cyclic dma tx's handler sdma_handle_channel_loop(),
SDMA channel statue is set to either DMA_ERROR or DMA_IN_PROGRESS
based on each period's status. This has the following issues:

1) If one period's status is BD_RROR, then channel status
   will be set to DMA_ERROR, but it will be overwritten to DMA_IN_PROGRESS
   if the following periods are OK.
2) DMA client may call sdma_control(DMA_TERMINATE_ALL) to stop the cyclic dma
   operation, sdma channel status will be set to DMA_ERROR,
   but if after this handler is called, then again the channel status will be overwritten
   to DMA_IN_PROGRESS. Then the following dmaengine_prep_dma_cyclic() will always fail,
   as channel status is DMA_IN_PROGRESS.

As in cyclic dma tx, channel status will be initially set to DMA_IN_PROGRESS,
driver only needs to change it to DMA_ERROR, when something wrong happens
(one period status is wrong, or stoped by client explicitly).

Signed-off-by: Jiada Wang <jiada_wang@mentor.com>
---
 drivers/dma/imx-sdma.c |    2 --
 1 file changed, 2 deletions(-)

diff --git a/drivers/dma/imx-sdma.c b/drivers/dma/imx-sdma.c
index 19041ce..1287146 100644
--- a/drivers/dma/imx-sdma.c
+++ b/drivers/dma/imx-sdma.c
@@ -607,8 +607,6 @@ static void sdma_handle_channel_loop(struct sdma_channel *sdmac)
 
 		if (bd->mode.status & BD_RROR)
 			sdmac->status = DMA_ERROR;
-		else
-			sdmac->status = DMA_IN_PROGRESS;
 
 		bd->mode.status |= BD_DONE;
 		sdmac->buf_tail++;
-- 
1.7.9.5

^ permalink raw reply related	[flat|nested] 4+ messages in thread
* [PATCH] dma: imx: correct sdmac->status for cyclic dma tx
@ 2013-12-13  5:52 jiada_wang at mentor.com
  2014-05-14 21:42 ` Fabio Estevam
  0 siblings, 1 reply; 4+ messages in thread
From: jiada_wang at mentor.com @ 2013-12-13  5:52 UTC (permalink / raw)
  To: linux-arm-kernel

From: Jiada Wang <jiada_wang@mentor.com>

In cyclic dma tx's handler sdma_handle_channel_loop(),
SDMA channel statue is set to either DMA_ERROR or DMA_IN_PROGRESS
based on each period's status. This has the following issues:

1) If one period's status is BD_RROR, then channel status
   will be set to DMA_ERROR, but it will be overwritten to DMA_IN_PROGRESS
   if the following periods are OK.
2) DMA client may call sdma_control(DMA_TERMINATE_ALL) to stop the cyclic dma
   operation, sdma channel status will be set to DMA_ERROR,
   but if after this handler is called, then again the channel status will be overwritten
   to DMA_IN_PROGRESS. Then the following dmaengine_prep_dma_cyclic() will always fail,
   as channel status is DMA_IN_PROGRESS.

As in cyclic dma tx, channel status will be initially set to DMA_IN_PROGRESS,
driver only needs to change it to DMA_ERROR, when something wrong happens
(one period status is wrong, or stoped by client explicitly).

Signed-off-by: Jiada Wang <jiada_wang@mentor.com>
---
 drivers/dma/imx-sdma.c | 2 --
 1 file changed, 2 deletions(-)

diff --git a/drivers/dma/imx-sdma.c b/drivers/dma/imx-sdma.c
index c75679d..c8a0094 100644
--- a/drivers/dma/imx-sdma.c
+++ b/drivers/dma/imx-sdma.c
@@ -605,8 +605,6 @@ static void sdma_handle_channel_loop(struct sdma_channel *sdmac)
 
 		if (bd->mode.status & BD_RROR)
 			sdmac->status = DMA_ERROR;
-		else
-			sdmac->status = DMA_IN_PROGRESS;
 
 		bd->mode.status |= BD_DONE;
 		sdmac->buf_tail++;
-- 
1.8.1.2

^ permalink raw reply related	[flat|nested] 4+ messages in thread

end of thread, other threads:[~2014-06-01 11:40 UTC | newest]

Thread overview: 4+ messages (download: mbox.gz follow: Atom feed
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2014-05-15  1:22 [PATCH] dma: imx: correct sdmac->status for cyclic dma tx jiada_wang at mentor.com
2014-06-01 11:40 ` Vinod Koul
  -- strict thread matches above, loose matches on Subject: below --
2013-12-13  5:52 jiada_wang at mentor.com
2014-05-14 21:42 ` Fabio Estevam

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