In callback function xdma_prep_device_sg(), it is nice to check if there
is zero length segment and skip it in the input scatter list.
Reported-by: Martin Tuma <[email protected]>
Link: https://lore.kernel.org/dmaengine/[email protected]/T/#t
Signed-off-by: Lizhi Hou <[email protected]>
---
drivers/dma/xilinx/xdma.c | 6 ++++--
1 file changed, 4 insertions(+), 2 deletions(-)
diff --git a/drivers/dma/xilinx/xdma.c b/drivers/dma/xilinx/xdma.c
index 462109c61653..5134757e88b1 100644
--- a/drivers/dma/xilinx/xdma.c
+++ b/drivers/dma/xilinx/xdma.c
@@ -465,6 +465,8 @@ xdma_prep_device_sg(struct dma_chan *chan, struct scatterlist *sgl,
for_each_sg(sgl, sg, sg_len, i)
desc_num += DIV_ROUND_UP(sg_dma_len(sg), XDMA_DESC_BLEN_MAX);
+ if (!desc_num)
+ return NULL;
sw_desc = xdma_alloc_desc(xdma_chan, desc_num);
if (!sw_desc)
@@ -488,7 +490,7 @@ xdma_prep_device_sg(struct dma_chan *chan, struct scatterlist *sgl,
addr = sg_dma_address(sg);
rest = sg_dma_len(sg);
- do {
+ while (rest) {
len = min_t(u32, rest, XDMA_DESC_BLEN_MAX);
/* set hardware descriptor */
desc->bytes = cpu_to_le32(len);
@@ -506,7 +508,7 @@ xdma_prep_device_sg(struct dma_chan *chan, struct scatterlist *sgl,
dev_addr += len;
addr += len;
rest -= len;
- } while (rest);
+ };
}
tx_desc = vchan_tx_prep(&xdma_chan->vchan, &sw_desc->vdesc, flags);
--
2.27.0