[PATCH v2 4/6] dmaengine: sprd: Fix block length overflow

From: Baolin Wang
Date: Mon May 06 2019 - 03:29:43 EST


From: Eric Long <eric.long@xxxxxxxxxx>

The maximum value of block length is 0xffff, so if the configured transfer length
is more than 0xffff, that will cause block length overflow to lead a configuration
error.

Thus we can set block length as the maximum burst length to avoid this issue, since
the maximum burst length will not be a big value which is more than 0xffff.

Signed-off-by: Eric Long <eric.long@xxxxxxxxxx>
Signed-off-by: Baolin Wang <baolin.wang@xxxxxxxxxx>
---
drivers/dma/sprd-dma.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/dma/sprd-dma.c b/drivers/dma/sprd-dma.c
index 0f92e60..a01c232 100644
--- a/drivers/dma/sprd-dma.c
+++ b/drivers/dma/sprd-dma.c
@@ -778,7 +778,7 @@ static int sprd_dma_fill_desc(struct dma_chan *chan,
temp |= slave_cfg->src_maxburst & SPRD_DMA_FRG_LEN_MASK;
hw->frg_len = temp;

- hw->blk_len = len & SPRD_DMA_BLK_LEN_MASK;
+ hw->blk_len = slave_cfg->src_maxburst & SPRD_DMA_BLK_LEN_MASK;
hw->trsc_len = len & SPRD_DMA_TRSC_LEN_MASK;

temp = (dst_step & SPRD_DMA_TRSF_STEP_MASK) << SPRD_DMA_DEST_TRSF_STEP_OFFSET;
--
1.7.9.5