From mboxrd@z Thu Jan 1 00:00:00 1970 From: Peter Hurley Subject: [PATCH -next 2/5] serial: core: Claim port mutex for set_ldisc() Date: Wed, 5 Nov 2014 13:11:42 -0500 Message-ID: <1415211105-16668-3-git-send-email-peter@hurleysoftware.com> References: <1415211105-16668-1-git-send-email-peter@hurleysoftware.com> Return-path: In-Reply-To: <1415211105-16668-1-git-send-email-peter@hurleysoftware.com> Sender: linux-kernel-owner@vger.kernel.org To: Greg Kroah-Hartman Cc: Jiri Slaby , One Thousand Gnomes , linux-serial@vger.kernel.org, linux-kernel@vger.kernel.org, Nicolas Ferre , Peter Hurley List-Id: linux-serial@vger.kernel.org Three UART drivers (8250, atmel & amba-pl010) enable modem status interrupts if the line discipline is changed to N_PPS. However, the uart port flags may only be safely modified while holding the port mutex. Signed-off-by: Peter Hurley --- drivers/tty/serial/serial_core.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) diff --git a/drivers/tty/serial/serial_core.c b/drivers/tty/serial/serial_core.c index 1a2d90f..5209eaa 100644 --- a/drivers/tty/serial/serial_core.c +++ b/drivers/tty/serial/serial_core.c @@ -1245,8 +1245,11 @@ static void uart_set_ldisc(struct tty_struct *tty) struct uart_state *state = tty->driver_data; struct uart_port *uport = state->uart_port; - if (uport->ops->set_ldisc) + if (uport->ops->set_ldisc) { + mutex_lock(&state->port.mutex); uport->ops->set_ldisc(uport, tty->termios.c_line); + mutex_unlock(&state->port.mutex); + } } static void uart_set_termios(struct tty_struct *tty, -- 2.1.3