When a signal interrupts tty_wait_until_sent() on a UART device, there might be data left on the xmit buffer that the UART will never transmit. This causes set_termios() to wait forever in tty_wait_until_sent(). The hang reproduces easily on my system that is equipped with DesignWare 8250. Run while true; do echo -ne 0123456789abcdef01 > /dev/ttyS1; done Hit Ctrl-C to interrupt the loop. When data is left in the struct uart_state xmit buffer, the following command hangs: stty -F /dev/ttyS1 raw -echo Call tty_driver_flush_buffer() on signal interrupted wait, to discard data from the xmit buffer. Signed-off-by: Baruch Siach <baruch@xxxxxxxxxx> --- drivers/tty/tty_ioctl.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/drivers/tty/tty_ioctl.c b/drivers/tty/tty_ioctl.c index 507a25d692bb..0bf6fad7ecb3 100644 --- a/drivers/tty/tty_ioctl.c +++ b/drivers/tty/tty_ioctl.c @@ -203,6 +203,8 @@ void tty_wait_until_sent(struct tty_struct *tty, long timeout) timeout = wait_event_interruptible_timeout(tty->write_wait, !tty_chars_in_buffer(tty), timeout); + if (timeout == -ERESTARTSYS && tty->closing) + tty_driver_flush_buffer(tty); if (timeout <= 0) return; -- 2.33.0
