From 8e2e27c7444ba7880aa0a4cb07a79de130d0ed93 Mon Sep 17 00:00:00 2001 From: Richard Zhao Date: Mon, 4 Jun 2012 09:17:24 +0800 Subject: 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 Acked-by: Shawn Guo Signed-off-by: Vinod Koul 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); -- cgit v0.10.2