tty: rework break handling

Some hardware needs to do break handling itself and may have partial
support only. Make break_ctl return an error code. Add a tty driver flag
so you can indicate driver hardware side break support.

Signed-off-by: Alan Cox <alan@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 2 insertions, 1 deletions

diff --git a/drivers/serial/serial_core.c b/drivers/serial/serial_core.c
index 0bce1fe2c62a..f977c98cfa95 100644
--- a/drivers/serial/serial_core.c
+++ b/drivers/serial/serial_core.c
@@ -934,7 +934,7 @@ uart_tiocmset(struct tty_struct *tty, struct file *file,
         return ret;
 }
 
-static void uart_break_ctl(struct tty_struct *tty, int break_state)
+static int uart_break_ctl(struct tty_struct *tty, int break_state)
 {
         struct uart_state *state = tty->driver_data;
         struct uart_port *port = state->port;
@@ -945,6 +945,7 @@ static void uart_break_ctl(struct tty_struct *tty, int break_state)
                 port->ops->break_ctl(port, break_state);
 
         mutex_unlock(&state->mutex);
+        return 0;
 }
 
 static int uart_do_autoconfig(struct uart_state *state)