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

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

[Anatolij Gustschin]

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@denx.de>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Sascha Hauer <s.hauer@pengutronix.de>
---
 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

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

[Sascha Hauer]

On Mon, Nov 22, 2010 at 06:35:18PM +0100, Anatolij Gustschin wrote:
> 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@denx.de>
> Cc: Dan Williams <dan.j.williams@intel.com>
> Cc: Sascha Hauer <s.hauer@pengutronix.de>

Acked-by: Sascha Hauer <s.hauer@pengutronix.de>

> ---
>  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
> 
> 

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