[PATCH] dmaengine: imx-sdma: fix bug in buffer descriptor initialization

From: Anatolij Gustschin
Date: Mon Nov 22 2010 - 12:35:32 EST


Currently while submitting scatterlists with more than one SG
entry the DMA buffer address from the first SG entry is inserted
into all initialized DMA buffer descriptors. This is due to the
typo in the for_each_sg() loop where the scatterlist pointer is
used for obtaining the DMA buffer address and _not_ the SG list
iterator.

As a result all received data will be written only into the first
DMA buffer while reading. While writing the data from the first
DMA buffer is send to the device multiple times. This caused
the filesystem destruction on the MMC card when using DMA in
mxcmmc driver.

Signed-off-by: Anatolij Gustschin <agust@xxxxxxx>
Cc: Dan Williams <dan.j.williams@xxxxxxxxx>
Cc: Sascha Hauer <s.hauer@xxxxxxxxxxxxxx>
---
drivers/dma/imx-sdma.c | 2 +-
1 files changed, 1 insertions(+), 1 deletions(-)

diff --git a/drivers/dma/imx-sdma.c b/drivers/dma/imx-sdma.c
index 0834323..13d6447 100644
--- a/drivers/dma/imx-sdma.c
+++ b/drivers/dma/imx-sdma.c
@@ -951,7 +951,7 @@ static struct dma_async_tx_descriptor *sdma_prep_slave_sg(
struct sdma_buffer_descriptor *bd = &sdmac->bd[i];
int param;

- bd->buffer_addr = sgl->dma_address;
+ bd->buffer_addr = sg->dma_address;

count = sg->length;

--
1.7.1

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/