blob: ab60366d79f395795c004072e5e3e59882c02cb7 [file] [log] [blame]
From b556278853e6d805821376ced27e288a611b2690 Mon Sep 17 00:00:00 2001
From: Peng Fan <>
Date: Thu, 7 Nov 2019 06:42:53 +0000
Subject: [PATCH] tty: serial: imx: use the sg count from dma_map_sg
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 <>
Signed-off-by: Greg Kroah-Hartman <>
Signed-off-by: Paul Gortmaker <>
diff --git a/drivers/tty/serial/imx.c b/drivers/tty/serial/imx.c
index 10db3e54ac9e..e87e4b06a40d 100644
--- a/drivers/tty/serial/imx.c
+++ b/drivers/tty/serial/imx.c
@@ -625,7 +625,7 @@ static void imx_uart_dma_tx(struct imx_port *sport)
dev_err(dev, "DMA mapping error for TX.\n");
- desc = dmaengine_prep_slave_sg(chan, sgl, sport->dma_tx_nents,
+ desc = dmaengine_prep_slave_sg(chan, sgl, ret,
if (!desc) {
dma_unmap_sg(dev, sgl, sport->dma_tx_nents,