From 689379c2f383b1fdfdff03e84cf659daf62f2088 Mon Sep 17 00:00:00 2001 From: Baolin Wang Date: Fri, 30 Aug 2019 15:37:45 +0800 Subject: 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 Link: https://lore.kernel.org/r/77868edb7aff9d5cb12ac3af8827ef2e244441a6.1567150471.git.baolin.wang@linaro.org Signed-off-by: Vinod Koul --- drivers/dma/sprd-dma.c | 10 ++++++++-- 1 file changed, 8 insertions(+), 2 deletions(-) (limited to 'drivers/dma') 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; -- cgit v1.2.3