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, 3 insertions, 2 deletions

diff --git a/drivers/char/esp.c b/drivers/char/esp.c
index 2eaf09f93e3d..7f077c0097f6 100644
--- a/drivers/char/esp.c
+++ b/drivers/char/esp.c
@@ -1725,13 +1725,13 @@ static int esp_tiocmset(struct tty_struct *tty, struct file *file,
 /*
  * rs_break() --- routine which turns the break handling on or off
  */
-static void esp_break(struct tty_struct *tty, int break_state)
+static int esp_break(struct tty_struct *tty, int break_state)
 {
         struct esp_struct *info = tty->driver_data;
         unsigned long flags;
 
         if (serial_paranoia_check(info, tty->name, "esp_break"))
-                return;
+                return -EINVAL;
 
         if (break_state == -1) {
                 spin_lock_irqsave(&info->lock, flags);
@@ -1747,6 +1747,7 @@ static void esp_break(struct tty_struct *tty, int break_state)
                 serial_out(info, UART_ESI_CMD2, 0x00);
                 spin_unlock_irqrestore(&info->lock, flags);
         }
+        return 0;
 }
 
 static int rs_ioctl(struct tty_struct *tty, struct file *file,