From 7d07ada047a4e1f5ff98757ce34c0fdd13d8ec93 Mon Sep 17 00:00:00 2001 From: =?utf8?q?Uwe=20Kleine-K=C3=B6nig?= Date: Mon, 27 Jul 2015 18:09:33 +0200 Subject: [PATCH] serial: mpc52xx: let tx_empty callback return either 0 or TIOCSER_TEMT MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit Documenation/serial/driver requests that the tx_empty callback should return 0 if there are still chars in the fifo or shifter or TIOCSER_TEMT (0x01) if no character is pending to be sent. Fix the mpc52xx serial driver to not return MPC52xx_PSC_SR_TXEMP (i.e. 0x0800) but TIOCSER_TEMT as documented. Signed-off-by: Uwe Kleine-König Signed-off-by: Greg Kroah-Hartman --- drivers/tty/serial/mpc52xx_uart.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) diff --git a/drivers/tty/serial/mpc52xx_uart.c b/drivers/tty/serial/mpc52xx_uart.c index 6fc07eb9d74e..41de374d9784 100644 --- a/drivers/tty/serial/mpc52xx_uart.c +++ b/drivers/tty/serial/mpc52xx_uart.c @@ -239,8 +239,9 @@ static int mpc52xx_psc_tx_rdy(struct uart_port *port) static int mpc52xx_psc_tx_empty(struct uart_port *port) { - return in_be16(&PSC(port)->mpc52xx_psc_status) - & MPC52xx_PSC_SR_TXEMP; + u16 sts = in_be16(&PSC(port)->mpc52xx_psc_status); + + return (sts & MPC52xx_PSC_SR_TXEMP) ? TIOCSER_TEMT : 0; } static void mpc52xx_psc_start_tx(struct uart_port *port) -- 2.11.0