serial: mpc52xx: let tx_empty callback return either 0 or TIOCSER_TEMT

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@pengutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Uwe Kleine-König 2015-07-27 18:09:33 +02:00 committed by Greg Kroah-Hartman
parent 7b9c5162c1
commit 7d07ada047

View file

@ -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)