Re: [RESEND PATCH] dma: imx-sdma: buf_tail should be initialize inprepare function

From: Vinod Koul
Date: Thu Jun 07 2012 - 04:26:54 EST


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 <richard.zhao@xxxxxxxxxxxxx>
> Acked-by: Shawn Guo <shawn.guo@xxxxxxxxxx>
> ---
> 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

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