From 341b9419a8c0a4cdb75773c576870f1eb655516d Mon Sep 17 00:00:00 2001 From: Shawn Guo Date: Thu, 20 Jan 2011 05:50:39 +0800 Subject: [PATCH] dmaengine: imx-sdma: fix up param for the last BD in sdma_prep_slave_sg() As per the reference manual, bit "L" should be set while bit "C" should be cleared for the last buffer descriptor in the non-cyclic chain, so that sdma can stop trying to find the next BD and end the transfer. In case of sdma_prep_slave_sg(), BD_LAST needs to be set and BD_CONT be cleared for the last BD. Signed-off-by: Shawn Guo Signed-off-by: Sascha Hauer --- drivers/dma/imx-sdma.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) diff --git a/drivers/dma/imx-sdma.c b/drivers/dma/imx-sdma.c index cf93d17..4535f98 100644 --- a/drivers/dma/imx-sdma.c +++ b/drivers/dma/imx-sdma.c @@ -931,8 +931,11 @@ static struct dma_async_tx_descriptor *sdma_prep_slave_sg( param = BD_DONE | BD_EXTD | BD_CONT; - if (i + 1 == sg_len) + if (i + 1 == sg_len) { param |= BD_INTR; + param |= BD_LAST; + param &= ~BD_CONT; + } dev_dbg(sdma->dev, "entry %d: count: %d dma: 0x%08x %s%s\n", i, count, sg->dma_address, -- 2.7.4