2012-06-04 01:17:36

by Richard Zhao

Subject: [RESEND PATCH] dma: imx-sdma: buf_tail should be initialize in prepare function

This fix audio underrun issue. When SNDRV_PCM_TRIGGER_STOP
and SNDRV_PCM_TRIGGER_START, it calls prepare again. buf_tail
should be reset to zero.
So move buf_tail initialization into prepare function.

Signed-off-by: Richard Zhao <[email protected]>
Acked-by: Shawn Guo <[email protected]>
---
drivers/dma/imx-sdma.c | 6 ++++--
1 files changed, 4 insertions(+), 2 deletions(-)

diff --git a/drivers/dma/imx-sdma.c b/drivers/dma/imx-sdma.c
index fb4f499..1dc2a4a 100644
--- a/drivers/dma/imx-sdma.c
+++ b/drivers/dma/imx-sdma.c
@@ -815,8 +815,6 @@ static int sdma_request_channel(struct sdma_channel *sdmac)

init_completion(&sdmac->done);

- sdmac->buf_tail = 0;
-
return 0;
out:

@@ -927,6 +925,8 @@ static struct dma_async_tx_descriptor *sdma_prep_slave_sg(

sdmac->flags = 0;

+ sdmac->buf_tail = 0;
+
dev_dbg(sdma->dev, "setting up %d entries for channel %d.\n",
sg_len, channel);

@@ -1027,6 +1027,8 @@ static struct dma_async_tx_descriptor *sdma_prep_dma_cyclic(

sdmac->status = DMA_IN_PROGRESS;

+ sdmac->buf_tail = 0;
+
sdmac->flags |= IMX_DMA_SG_LOOP;
sdmac->direction = direction;
ret = sdma_load_context(sdmac);
--
1.7.5.4

2012-06-07 08:27:00

by Vinod Koul

Subject: Re: [RESEND PATCH] dma: imx-sdma: buf_tail should be initialize in prepare function

On Mon, 2012-06-04 at 09:17 +0800, Richard Zhao wrote:
> This fix audio underrun issue. When SNDRV_PCM_TRIGGER_STOP
> and SNDRV_PCM_TRIGGER_START, it calls prepare again. buf_tail
> should be reset to zero.
> So move buf_tail initialization into prepare function.
>
> Signed-off-by: Richard Zhao <[email protected]>
> Acked-by: Shawn Guo <[email protected]>
> ---
> drivers/dma/imx-sdma.c | 6 ++++--
> 1 files changed, 4 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/dma/imx-sdma.c b/drivers/dma/imx-sdma.c
> index fb4f499..1dc2a4a 100644
> --- a/drivers/dma/imx-sdma.c
> +++ b/drivers/dma/imx-sdma.c
> @@ -815,8 +815,6 @@ static int sdma_request_channel(struct sdma_channel *sdmac)
>
> init_completion(&sdmac->done);
>
> - sdmac->buf_tail = 0;
> -
> return 0;
> out:
>
> @@ -927,6 +925,8 @@ static struct dma_async_tx_descriptor *sdma_prep_slave_sg(
>
> sdmac->flags = 0;
>
> + sdmac->buf_tail = 0;
> +
> dev_dbg(sdma->dev, "setting up %d entries for channel %d.\n",
> sg_len, channel);
>
> @@ -1027,6 +1027,8 @@ static struct dma_async_tx_descriptor *sdma_prep_dma_cyclic(
>
> sdmac->status = DMA_IN_PROGRESS;
>
> + sdmac->buf_tail = 0;
> +
> sdmac->flags |= IMX_DMA_SG_LOOP;
> sdmac->direction = direction;
> ret = sdma_load_context(sdmac);

Applied, Thanks
--
~Vinod