aboutsummaryrefslogtreecommitdiffstats
path: root/drivers/dma/amba-pl08x.c
diff options
context:
space:
mode:
authorLars-Peter Clausen <lars@metafoo.de>2012-04-25 14:50:52 -0400
committerVinod Koul <vinod.koul@linux.intel.com>2012-05-11 02:34:38 -0400
commitfdaf9c4b22247a6cc6cda9459be3e52764c14d95 (patch)
treec567736f1f47f91003a658b11075e974cee4321b /drivers/dma/amba-pl08x.c
parentcbb796ccd8c33c50249b876d9773dfa8e67d39cb (diff)
dmaengine: Use dma_sg_len(sg) instead of sg->length
sg->length may or may not contain the length of the dma region to transfer, depending on the architecture - dma_sg_len(sg) always will though. For the architectures which use the drivers modified by this patch it probably is the case that sg->length contains the dma transfer length. But to be consistent and future proof change them to use dma_sg_len. To quote Russel King: sg->length is meaningless to something performing DMA. In cases where sg_dma_len(sg) and sg->length are the same storage, then there's no problem. But scatterlists _can_ (and one some architectures) do split them - especially when you have an IOMMU which can allow you to combine a scatterlist into fewer entries. So, anything using sg->length for the size of a scatterlist's DMA transfer _after_ a call to dma_map_sg() is almost certainly buggy. The patch has been generated using the following coccinelle patch: <smpl> @@ struct scatterlist *sg; expression X; @@ -sg[X].length +sg_dma_len(&sg[X]) @@ struct scatterlist *sg; @@ -sg->length +sg_dma_len(sg) </smpl> Signed-off-by: Lars-Peter Clausen <lars@metafoo.de> Acked-by: Linus Walleij <linus.walleij@linaro.org> Signed-off-by: Vinod Koul <vinod.koul@linux.intel.com>
Diffstat (limited to 'drivers/dma/amba-pl08x.c')
-rw-r--r--drivers/dma/amba-pl08x.c2
1 files changed, 1 insertions, 1 deletions
diff --git a/drivers/dma/amba-pl08x.c b/drivers/dma/amba-pl08x.c
index 003220a60bcb..49ecbbb8932d 100644
--- a/drivers/dma/amba-pl08x.c
+++ b/drivers/dma/amba-pl08x.c
@@ -1328,7 +1328,7 @@ static struct dma_async_tx_descriptor *pl08x_prep_slave_sg(
1328 int ret, tmp; 1328 int ret, tmp;
1329 1329
1330 dev_dbg(&pl08x->adev->dev, "%s prepare transaction of %d bytes from %s\n", 1330 dev_dbg(&pl08x->adev->dev, "%s prepare transaction of %d bytes from %s\n",
1331 __func__, sgl->length, plchan->name); 1331 __func__, sg_dma_len(sgl), plchan->name);
1332 1332
1333 txd = pl08x_get_txd(plchan, flags); 1333 txd = pl08x_get_txd(plchan, flags);
1334 if (!txd) { 1334 if (!txd) {