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authorUwe Kleine-König <u.kleine-koenig@pengutronix.de>2018-03-02 13:07:29 +0300
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2018-03-09 21:21:02 +0300
commit48669b69e3ecbabbd2936fbbe095901ba83a37f9 (patch)
tree098d6397cf766169447427566f0fcebb5d899fba /drivers/tty
parent1866541492641c02874bf51f9d8712b5510f2c64 (diff)
downloadlinux-48669b69e3ecbabbd2936fbbe095901ba83a37f9.tar.xz
serial: imx: don't prepare to send if no data is available
serial_core might call the .start_tx callback without any data being available to send. In this case return early instead of going through all the setup needed for sending which might include disabling RX in RS485 half-duplex mode. Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/tty')
-rw-r--r--drivers/tty/serial/imx.c3
1 files changed, 3 insertions, 0 deletions
diff --git a/drivers/tty/serial/imx.c b/drivers/tty/serial/imx.c
index 80456ea2603a..3a954194d2f6 100644
--- a/drivers/tty/serial/imx.c
+++ b/drivers/tty/serial/imx.c
@@ -651,6 +651,9 @@ static void imx_start_tx(struct uart_port *port)
struct imx_port *sport = (struct imx_port *)port;
u32 ucr1;
+ if (!sport->port.x_char && uart_circ_empty(&port->state->xmit))
+ return;
+
if (port->rs485.flags & SER_RS485_ENABLED) {
u32 ucr2;