[PATCH 1/2] dmaengine: at_hdmac: fix comment in atc_prep_slave_sg()

[PATCH 1/2] dmaengine: at_hdmac: fix comment in atc_prep_slave_sg()

[Nicolas Ferre]

s/dma_memcpy/slave_sg/ and it is sg length that we are
talking about.

Signed-off-by: Nicolas Ferre <nicolas.ferre@atmel.com>
Cc: Stable <stable@vger.kernel.org> [2.6.31+]
---
 drivers/dma/at_hdmac.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/dma/at_hdmac.c b/drivers/dma/at_hdmac.c
index 3934fcc..6c09e18 100644
--- a/drivers/dma/at_hdmac.c
+++ b/drivers/dma/at_hdmac.c
@@ -661,7 +661,7 @@ atc_prep_slave_sg(struct dma_chan *chan, struct scatterlist *sgl,
 			flags);
 
 	if (unlikely(!atslave || !sg_len)) {
-		dev_dbg(chan2dev(chan), "prep_dma_memcpy: length is zero!\n");
+		dev_dbg(chan2dev(chan), "prep_slave_sg: sg length is zero!\n");
 		return NULL;
 	}
 
-- 
1.7.10

[PATCH 2/2] dmaengine: at_hdmac: check that each sg data length is non-null

[Nicolas Ferre]

Avoid the construction of a malformed DMA request sent to
the DMA controller.
Log message is for debug only because this condition is unlikely to
append and may only trigger at driver development time.

Signed-off-by: Nicolas Ferre <nicolas.ferre@atmel.com>
Cc: Stable <stable@vger.kernel.org> [2.6.31+]
---
 drivers/dma/at_hdmac.c |   11 +++++++++++
 1 file changed, 11 insertions(+)

diff --git a/drivers/dma/at_hdmac.c b/drivers/dma/at_hdmac.c
index 6c09e18..7ab6e26 100644
--- a/drivers/dma/at_hdmac.c
+++ b/drivers/dma/at_hdmac.c
@@ -689,6 +689,11 @@ atc_prep_slave_sg(struct dma_chan *chan, struct scatterlist *sgl,
 
 			mem = sg_dma_address(sg);
 			len = sg_dma_len(sg);
+			if (unlikely(!len)) {
+				dev_dbg(chan2dev(chan),
+					"prep_slave_sg: sg(%d) data length is zero\n", i);
+				goto err;
+			}
 			mem_width = 2;
 			if (unlikely(mem & 3 || len & 3))
 				mem_width = 0;
@@ -724,6 +729,11 @@ atc_prep_slave_sg(struct dma_chan *chan, struct scatterlist *sgl,
 
 			mem = sg_dma_address(sg);
 			len = sg_dma_len(sg);
+			if (unlikely(!len)) {
+				dev_dbg(chan2dev(chan),
+					"prep_slave_sg: sg(%d) data length is zero\n", i);
+				goto err;
+			}
 			mem_width = 2;
 			if (unlikely(mem & 3 || len & 3))
 				mem_width = 0;
@@ -757,6 +767,7 @@ atc_prep_slave_sg(struct dma_chan *chan, struct scatterlist *sgl,
 
 err_desc_get:
 	dev_err(chan2dev(chan), "not enough descriptors available\n");
+err:
 	atc_desc_put(atchan, first);
 	return NULL;
 }
-- 
1.7.10

Re: [PATCH 1/2] dmaengine: at_hdmac: fix comment in atc_prep_slave_sg()

[Vinod Koul]

On Tue, 2012-09-11 at 17:21 +0200, Nicolas Ferre wrote:
> s/dma_memcpy/slave_sg/ and it is sg length that we are
> talking about.
> 
> Signed-off-by: Nicolas Ferre <nicolas.ferre@atmel.com>
> Cc: Stable <stable@vger.kernel.org> [2.6.31+]
> ---
>  drivers/dma/at_hdmac.c |    2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/drivers/dma/at_hdmac.c b/drivers/dma/at_hdmac.c
> index 3934fcc..6c09e18 100644
> --- a/drivers/dma/at_hdmac.c
> +++ b/drivers/dma/at_hdmac.c
> @@ -661,7 +661,7 @@ atc_prep_slave_sg(struct dma_chan *chan, struct scatterlist *sgl,
>  			flags);
>  
>  	if (unlikely(!atslave || !sg_len)) {
> -		dev_dbg(chan2dev(chan), "prep_dma_memcpy: length is zero!\n");
> +		dev_dbg(chan2dev(chan), "prep_slave_sg: sg length is zero!\n");
>  		return NULL;
>  	}
Applied both, Thanks.

I will send this to Linus in couple of days


-- 
~Vinod