summaryrefslogtreecommitdiff
diff options
context:
space:
mode:
authorBaolin Wang <baolin.wang@linaro.org>2019-08-30 10:37:45 +0300
committerVinod Koul <vkoul@kernel.org>2019-09-04 08:55:38 +0300
commit689379c2f383b1fdfdff03e84cf659daf62f2088 (patch)
treef52c1aedf8afe47d585e775480744a019a7b656a
parent962411b05a6d3342aa649e39cda1704c1fc042c6 (diff)
downloadlinux-689379c2f383b1fdfdff03e84cf659daf62f2088.tar.xz
dmaengine: sprd: Fix the DMA link-list configuration
For the Spreadtrum DMA link-list mode, when the DMA engine got a slave hardware request, which will trigger the DMA engine to load the DMA configuration from the link-list memory automatically. But before the slave hardware request, the slave will get an incorrect residue due to the first node used to trigger the link-list was configured as the last source address and destination address. Thus we should make sure the first node was configured the start source address and destination address, which can fix this issue. Fixes: 4ac695464763 ("dmaengine: sprd: Support DMA link-list mode") Signed-off-by: Baolin Wang <baolin.wang@linaro.org> Link: https://lore.kernel.org/r/77868edb7aff9d5cb12ac3af8827ef2e244441a6.1567150471.git.baolin.wang@linaro.org Signed-off-by: Vinod Koul <vkoul@kernel.org>
-rw-r--r--drivers/dma/sprd-dma.c10
1 files changed, 8 insertions, 2 deletions
diff --git a/drivers/dma/sprd-dma.c b/drivers/dma/sprd-dma.c
index baac476c8622..525dc7338fe3 100644
--- a/drivers/dma/sprd-dma.c
+++ b/drivers/dma/sprd-dma.c
@@ -908,6 +908,7 @@ sprd_dma_prep_slave_sg(struct dma_chan *chan, struct scatterlist *sgl,
struct sprd_dma_chn *schan = to_sprd_dma_chan(chan);
struct dma_slave_config *slave_cfg = &schan->slave_cfg;
dma_addr_t src = 0, dst = 0;
+ dma_addr_t start_src = 0, start_dst = 0;
struct sprd_dma_desc *sdesc;
struct scatterlist *sg;
u32 len = 0;
@@ -954,6 +955,11 @@ sprd_dma_prep_slave_sg(struct dma_chan *chan, struct scatterlist *sgl,
dst = sg_dma_address(sg);
}
+ if (!i) {
+ start_src = src;
+ start_dst = dst;
+ }
+
/*
* The link-list mode needs at least 2 link-list
* configurations. If there is only one sg, it doesn't
@@ -970,8 +976,8 @@ sprd_dma_prep_slave_sg(struct dma_chan *chan, struct scatterlist *sgl,
}
}
- ret = sprd_dma_fill_desc(chan, &sdesc->chn_hw, 0, 0, src, dst, len,
- dir, flags, slave_cfg);
+ ret = sprd_dma_fill_desc(chan, &sdesc->chn_hw, 0, 0, start_src,
+ start_dst, len, dir, flags, slave_cfg);
if (ret) {
kfree(sdesc);
return NULL;