From: Peng Fan <peng.fan@xxxxxxx>
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".
When enabling iommu for lpuart + edma, iommu framework may concatenate
two sgs into one.
Fixes: 6250cc30c4c4e ("tty: serial: fsl_lpuart: Use scatter/gather DMA for Tx")
Cc: <stable@xxxxxxxxxxxxxxx>
Signed-off-by: Peng Fan <peng.fan@xxxxxxx>
---
V2:
Assign ret to sport->dma_tx_nents, then we no need to fix dma_unmap_sg
Hi Greg,
I saw v1 patch merged to tty-next, please help to replace with V2 if this
is ok for you, or you need I have a follow up fix for v1.
drivers/tty/serial/fsl_lpuart.c | 1 +
1 file changed, 1 insertion(+)
diff --git a/drivers/tty/serial/fsl_lpuart.c b/drivers/tty/serial/fsl_lpuart.c
index 3e17bb8a0b16..ec5ea098669e 100644
--- a/drivers/tty/serial/fsl_lpuart.c
+++ b/drivers/tty/serial/fsl_lpuart.c
@@ -436,6 +436,7 @@ static void lpuart_dma_tx(struct lpuart_port *sport)
return;
}
+ sport->dma_tx_nents = ret;
sport->dma_tx_desc = dmaengine_prep_slave_sg(sport->dma_tx_chan, sgl,
sport->dma_tx_nents,
DMA_MEM_TO_DEV, DMA_PREP_INTERRUPT);
--
2.16.4
