Input: turbografx - use guard notation when acquiring mutex

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.

Link: https://lore.kernel.org/r/20240904043104.1030257-6-dmitry.torokhov@gmail.com
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>

diff --git a/drivers/input/joystick/turbografx.c b/drivers/input/joystick/turbografx.c
index 0a78dda..db696ba 100644 (file)
--- a/drivers/input/joystick/turbografx.c
+++ b/drivers/input/joystick/turbografx.c
@@ -103,33 +103,31 @@ static void tgfx_timer(struct timer_list *t)
 static int tgfx_open(struct input_dev *dev)
 {
        struct tgfx *tgfx = input_get_drvdata(dev);
-       int err;
 
-       err = mutex_lock_interruptible(&tgfx->sem);
-       if (err)
-               return err;
+       scoped_guard(mutex_intr, &tgfx->sem) {
+               if (!tgfx->used++) {
+                       parport_claim(tgfx->pd);
+                       parport_write_control(tgfx->pd->port, 0x04);
+                       mod_timer(&tgfx->timer, jiffies + TGFX_REFRESH_TIME);
+               }
 
-       if (!tgfx->used++) {
-               parport_claim(tgfx->pd);
-               parport_write_control(tgfx->pd->port, 0x04);
-               mod_timer(&tgfx->timer, jiffies + TGFX_REFRESH_TIME);
+               return 0;
        }
 
-       mutex_unlock(&tgfx->sem);
-       return 0;
+       return -EINTR;
 }
 
 static void tgfx_close(struct input_dev *dev)
 {
        struct tgfx *tgfx = input_get_drvdata(dev);
 
-       mutex_lock(&tgfx->sem);
+       guard(mutex)(&tgfx->sem);
+
        if (!--tgfx->used) {
                del_timer_sync(&tgfx->timer);
                parport_write_control(tgfx->pd->port, 0x00);
                parport_release(tgfx->pd);
        }
-       mutex_unlock(&tgfx->sem);
 }