dma: imx-sdma: buf_tail should be initialize in prepare function (8e2e27c7) · Commits · 戴 / test

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@freescale.com> Acked-by:

Shawn Guo <shawn.guo@linaro.org> Signed-off-by:

Vinod Koul <vinod.koul@linux.intel.com>

drivers/dma/imx-sdma.c

+4 −2

Original line number	Diff line number	Diff line
		@@ -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);

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