From 717f3bbab3c7628736ef738fdbf3d9a28578c26c Mon Sep 17 00:00:00 2001 From: Seth Bollinger <sethb@digi.com> Date: Tue, 25 Mar 2014 12:55:37 -0500 Subject: [PATCH] serial_core: Fix conditional start_tx on ring buffer not empty If the serial_core ring buffer empties just as the tty layer receives an XOFF, then start_tx will never be called when the tty layer receives an XON as the serial_core ring buffer is empty. This will possibly leave a few bytes trapped in the fifo for drivers that disable the transmitter when flow controlled. Signed-off-by: Seth Bollinger <sethb@digi.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> --- drivers/tty/serial/serial_core.c | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-) diff --git a/drivers/tty/serial/serial_core.c b/drivers/tty/serial/serial_core.c index 2cf5649a6dc038..dd1a7bef6647bf 100644 --- a/drivers/tty/serial/serial_core.c +++ b/drivers/tty/serial/serial_core.c @@ -89,8 +89,7 @@ static void __uart_start(struct tty_struct *tty) struct uart_state *state = tty->driver_data; struct uart_port *port = state->uart_port; - if (!uart_circ_empty(&state->xmit) && state->xmit.buf && - !tty->stopped && !tty->hw_stopped) + if (!tty->stopped && !tty->hw_stopped) port->ops->start_tx(port); } -- GitLab