Commit 717f3bba authored Mar 25, 2014 by Seth Bollinger Committed by Greg Kroah-Hartman Apr 16, 2014

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>

parent 4ea8dafd

drivers/tty/serial/serial_core.c

+1 −2

Original line number	Diff line number	Diff line
		@@ -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);
		}

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