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.fe...@atmel.com>
Cc: Stable <sta...@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
--
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