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| author | Lars-Peter Clausen <lars@metafoo.de> | 2012-04-25 20:50:52 +0200 |
|---|---|---|
| committer | Vinod Koul <vinod.koul@linux.intel.com> | 2012-05-11 12:04:38 +0530 |
| commit | fdaf9c4b22247a6cc6cda9459be3e52764c14d95 (patch) | |
| tree | c567736f1f47f91003a658b11075e974cee4321b /drivers/dma/intel_mid_dma.c | |
| parent | cbb796ccd8c33c50249b876d9773dfa8e67d39cb (diff) | |
| download | linux-fdaf9c4b22247a6cc6cda9459be3e52764c14d95.tar.gz | |
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/intel_mid_dma.c')
| -rw-r--r-- | drivers/dma/intel_mid_dma.c | 6 |
1 files changed, 3 insertions, 3 deletions
diff --git a/drivers/dma/intel_mid_dma.c b/drivers/dma/intel_mid_dma.c index d0ef5937fbf6..222e907bfaaa 100644 --- a/drivers/dma/intel_mid_dma.c +++ b/drivers/dma/intel_mid_dma.c @@ -394,7 +394,7 @@ static int midc_lli_fill_sg(struct intel_mid_dma_chan *midc, } } /*Populate CTL_HI values*/ - ctl_hi.ctlx.block_ts = get_block_ts(sg->length, + ctl_hi.ctlx.block_ts = get_block_ts(sg_dma_len(sg), desc->width, midc->dma->block_size); /*Populate SAR and DAR values*/ @@ -747,7 +747,7 @@ static struct dma_async_tx_descriptor *intel_mid_dma_prep_slave_sg( txd = intel_mid_dma_prep_memcpy(chan, mids->dma_slave.dst_addr, mids->dma_slave.src_addr, - sgl->length, + sg_dma_len(sgl), flags); return txd; } else { @@ -759,7 +759,7 @@ static struct dma_async_tx_descriptor *intel_mid_dma_prep_slave_sg( pr_debug("MDMA: SG Length = %d, direction = %d, Flags = %#lx\n", sg_len, direction, flags); - txd = intel_mid_dma_prep_memcpy(chan, 0, 0, sgl->length, flags); + txd = intel_mid_dma_prep_memcpy(chan, 0, 0, sg_dma_len(sgl), flags); if (NULL == txd) { pr_err("MDMA: Prep memcpy failed\n"); return NULL; |