[PATCH 2/6] Input: gamecon - use guard notation when acquiring mutex

[Dmitry Torokhov]

Using guard notation makes the code more compact and error handling
more robust by ensuring that mutexes are released in all code paths
when control leaves critical section.

Signed-off-by: Dmitry Torokhov <dmitry.torokhov@xxxxxxxxx>
---
 drivers/input/joystick/gamecon.c | 22 ++++++++++------------
 1 file changed, 10 insertions(+), 12 deletions(-)

diff --git a/drivers/input/joystick/gamecon.c b/drivers/input/joystick/gamecon.c
index c38de3094553..968c0e653f2e 100644
--- a/drivers/input/joystick/gamecon.c
+++ b/drivers/input/joystick/gamecon.c
@@ -765,33 +765,31 @@ static void gc_timer(struct timer_list *t)
 static int gc_open(struct input_dev *dev)
 {
 	struct gc *gc = input_get_drvdata(dev);
-	int err;
 
-	err = mutex_lock_interruptible(&gc->mutex);
-	if (err)
-		return err;
+	scoped_guard(mutex_intr, &gc->mutex) {
+		if (!gc->used++) {
+			parport_claim(gc->pd);
+			parport_write_control(gc->pd->port, 0x04);
+			mod_timer(&gc->timer, jiffies + GC_REFRESH_TIME);
+		}
 
-	if (!gc->used++) {
-		parport_claim(gc->pd);
-		parport_write_control(gc->pd->port, 0x04);
-		mod_timer(&gc->timer, jiffies + GC_REFRESH_TIME);
+		return 0;
 	}
 
-	mutex_unlock(&gc->mutex);
-	return 0;
+	return -EINTR;
 }
 
 static void gc_close(struct input_dev *dev)
 {
 	struct gc *gc = input_get_drvdata(dev);
 
-	mutex_lock(&gc->mutex);
+	guard(mutex)(&gc->mutex);
+
 	if (!--gc->used) {
 		del_timer_sync(&gc->timer);
 		parport_write_control(gc->pd->port, 0x00);
 		parport_release(gc->pd);
 	}
-	mutex_unlock(&gc->mutex);
 }
 
 static int gc_setup_pad(struct gc *gc, int idx, int pad_type)
-- 
2.46.0.469.g59c65b2a67-goog