tty: early return from send_break() on TTY_DRIVER_HARDWARE_BREAK

[ Upstream commit 66619686d187b4a6395316b7f39881e945dce4bc ]

If the driver sets TTY_DRIVER_HARDWARE_BREAK, we leave ops->break_ctl()
to the driver and return from send_break(). But we do it using a local
variable and keep the code flowing through the end of the function.
Instead, do 'return' immediately with the ops->break_ctl()'s return
value.

This way, we don't have to stuff the 'else' branch of the 'if' with the
software break handling. And we can re-indent the function too.

Signed-off-by: "Jiri Slaby (SUSE)" <jirislaby@kernel.org>
Link: https://lore.kernel.org/r/20230919085156.1578-14-jirislaby@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Stable-dep-of: 66aad7d8d3ec ("usb: cdc-acm: return correct error code on unsupported break")
Signed-off-by: Sasha Levin <sashal@kernel.org>

diff --git a/drivers/tty/tty_io.c b/drivers/tty/tty_io.c
index 8a94e5a43c6d2e64e4e24181a6acbc65deb0fbc6..b6ddc1bf307bccac0b47314787032f5816a7c715 100644 (file)
--- a/drivers/tty/tty_io.c
+++ b/drivers/tty/tty_io.c
@@ -2475,22 +2475,24 @@ static int send_break(struct tty_struct *tty, unsigned int duration)
                return 0;
 
        if (tty->driver->flags & TTY_DRIVER_HARDWARE_BREAK)
-               retval = tty->ops->break_ctl(tty, duration);
-       else {
-               /* Do the work ourselves */
-               if (tty_write_lock(tty, false) < 0)
-                       return -EINTR;
-               retval = tty->ops->break_ctl(tty, -1);
-               if (retval)
-                       goto out;
-               if (!signal_pending(current))
-                       msleep_interruptible(duration);
-               retval = tty->ops->break_ctl(tty, 0);
+               return tty->ops->break_ctl(tty, duration);
+
+       /* Do the work ourselves */
+       if (tty_write_lock(tty, false) < 0)
+               return -EINTR;
+
+       retval = tty->ops->break_ctl(tty, -1);
+       if (retval)
+               goto out;
+       if (!signal_pending(current))
+               msleep_interruptible(duration);
+       retval = tty->ops->break_ctl(tty, 0);
 out:
-               tty_write_unlock(tty);
-               if (signal_pending(current))
-                       retval = -EINTR;
-       }
+       tty_write_unlock(tty);
+
+       if (signal_pending(current))
+               retval = -EINTR;
+
        return retval;
 }