From: Peng Fan <peng.fan@xxxxxxx>
commit 596fd8dffb745afcebc0ec6968e17fe29f02044c upstream.
The dmaengine_prep_slave_sg needs to use sg count returned
by dma_map_sg, not use sport->dma_tx_nents, because the return
value of dma_map_sg is not always same with "nents".
Fixes: b4cdc8f61beb ("serial: imx: add DMA support for imx6q")
Signed-off-by: Peng Fan <peng.fan@xxxxxxx>
Link: https://lore.kernel.org/r/1573108875-26530-1-git-send-email-peng.fan@xxxxxxx
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/tty/serial/imx.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
--- a/drivers/tty/serial/imx.c
+++ b/drivers/tty/serial/imx.c
@@ -542,7 +542,7 @@ static void imx_dma_tx(struct imx_port *
dev_err(dev, "DMA mapping error for TX.\n");
return;
}
- desc = dmaengine_prep_slave_sg(chan, sgl, sport->dma_tx_nents,
+ desc = dmaengine_prep_slave_sg(chan, sgl, ret,
DMA_MEM_TO_DEV, DMA_PREP_INTERRUPT);
if (!desc) {
dma_unmap_sg(dev, sgl, sport->dma_tx_nents,
