Commit 48669b69 authored Mar 02, 2018 by Uwe Kleine-König Committed by Greg Kroah-Hartman Mar 09, 2018

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>

parent 18665414

drivers/tty/serial/imx.c

+3 −0

Original line number	Diff line number	Diff line
		@@ -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;

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