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 <u.kleine-koenig@xxxxxxxxxxxxxx> --- 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 1589f17c1fca..66dc4ea828f7 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) -- 2.1.4 -- To unsubscribe from this list: send the line "unsubscribe linux-serial" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html