[PATCH] dmaengine: imx-dma: Disable use of hw_chain to fix sg_dma transfers.

[PATCH] dmaengine: imx-dma: Disable use of hw_chain to fix sg_dma transfers.

[Javier Martin]

HW chaining is currently broken in imx-dma. It can be easily reproduced doing
intensive accesses to a external MMC card and checking how the file system
is corrupted.

Preventing the driver to use HW chaining solves these issues.


Signed-off-by: Javier Martin <javier.martin@vista-silicon.com>
---
 drivers/dma/imx-dma.c |    5 ++---
 1 file changed, 2 insertions(+), 3 deletions(-)

diff --git a/drivers/dma/imx-dma.c b/drivers/dma/imx-dma.c
index 5084975..03f3b64 100644
--- a/drivers/dma/imx-dma.c
+++ b/drivers/dma/imx-dma.c
@@ -643,9 +643,8 @@ static int imxdma_control(struct dma_chan *chan, enum dma_ctrl_cmd cmd,
 			break;
 		}
 
-		imxdmac->hw_chaining = 1;
-		if (!imxdma_hw_chain(imxdmac))
-			return -EINVAL;
+		imxdmac->hw_chaining = 0;
+
 		imxdmac->ccr_from_device = (mode | IMX_DMA_TYPE_FIFO) |
 			((IMX_DMA_MEMSIZE_32 | IMX_DMA_TYPE_LINEAR) << 2) |
 			CCR_REN;
-- 
1.7.9.5

Re: [PATCH] dmaengine: imx-dma: Disable use of hw_chain to fix sg_dma transfers.

[javier Martin]

On 30 October 2012 16:58, Javier Martin <javier.martin@vista-silicon.com> wrote:
> HW chaining is currently broken in imx-dma. It can be easily reproduced doing
> intensive accesses to a external MMC card and checking how the file system
> is corrupted.
>
> Preventing the driver to use HW chaining solves these issues.
>
>
> Signed-off-by: Javier Martin <javier.martin@vista-silicon.com>
> ---
>  drivers/dma/imx-dma.c |    5 ++---
>  1 file changed, 2 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/dma/imx-dma.c b/drivers/dma/imx-dma.c
> index 5084975..03f3b64 100644
> --- a/drivers/dma/imx-dma.c
> +++ b/drivers/dma/imx-dma.c
> @@ -643,9 +643,8 @@ static int imxdma_control(struct dma_chan *chan, enum dma_ctrl_cmd cmd,
>                         break;
>                 }
>
> -               imxdmac->hw_chaining = 1;
> -               if (!imxdma_hw_chain(imxdmac))
> -                       return -EINVAL;
> +               imxdmac->hw_chaining = 0;
> +
>                 imxdmac->ccr_from_device = (mode | IMX_DMA_TYPE_FIFO) |
>                         ((IMX_DMA_MEMSIZE_32 | IMX_DMA_TYPE_LINEAR) << 2) |
>                         CCR_REN;
> --
> 1.7.9.5
>

Hi Vinod,
I see you missed this patch for 3.7. Could you please apply it as a fix for 3.8?

Regards.

-- 
Javier Martin
Vista Silicon S.L.
CDTUC - FASE C - Oficina S-345
Avda de los Castros s/n
39005- Santander. Cantabria. Spain
+34 942 25 32 60
www.vista-silicon.com

Re: [PATCH] dmaengine: imx-dma: Disable use of hw_chain to fix sg_dma transfers.

[Vinod Koul]

On Fri, Jan 04, 2013 at 04:37:44PM +0100, javier Martin wrote:
> On 30 October 2012 16:58, Javier Martin <javier.martin@vista-silicon.com> wrote:
> > HW chaining is currently broken in imx-dma. It can be easily reproduced doing
> > intensive accesses to a external MMC card and checking how the file system
> > is corrupted.
> >
> > Preventing the driver to use HW chaining solves these issues.
> >
> >
Applied now.

Sorry for this miss & thanks for reminding

--
~Vinod