[PATCH v3 6/6] powerpc: sysdev: use lock guard for mutex

[Shrikanth Hegde <sshegde@linux.ibm.com>]

use guard(mutex) for scope based resource management of mutex
This would make the code simpler and easier to maintain.

More details on lock guards can be found at
https://lore.kernel.org/all/20230612093537.614161713@infradead.org/T/#u

Reviewed-by: Srikar Dronamraju <srikar@linux.ibm.com>
Signed-off-by: Shrikanth Hegde <sshegde@linux.ibm.com>
---
 arch/powerpc/sysdev/fsl_mpic_timer_wakeup.c | 14 +++-----------
 1 file changed, 3 insertions(+), 11 deletions(-)

diff --git a/arch/powerpc/sysdev/fsl_mpic_timer_wakeup.c b/arch/powerpc/sysdev/fsl_mpic_timer_wakeup.c
index ce6c739c51e5..06d9101a5d49 100644
--- a/arch/powerpc/sysdev/fsl_mpic_timer_wakeup.c
+++ b/arch/powerpc/sysdev/fsl_mpic_timer_wakeup.c
@@ -75,7 +75,7 @@ static ssize_t fsl_timer_wakeup_store(struct device *dev,
 	if (kstrtoll(buf, 0, &interval))
 		return -EINVAL;
 
-	mutex_lock(&sysfs_lock);
+	guard(mutex)(&sysfs_lock);
 
 	if (fsl_wakeup->timer) {
 		disable_irq_wake(fsl_wakeup->timer->irq);
@@ -83,31 +83,23 @@ static ssize_t fsl_timer_wakeup_store(struct device *dev,
 		fsl_wakeup->timer = NULL;
 	}
 
-	if (!interval) {
-		mutex_unlock(&sysfs_lock);
+	if (!interval)
 		return count;
-	}
 
 	fsl_wakeup->timer = mpic_request_timer(fsl_mpic_timer_irq,
 						fsl_wakeup, interval);
-	if (!fsl_wakeup->timer) {
-		mutex_unlock(&sysfs_lock);
+	if (!fsl_wakeup->timer)
 		return -EINVAL;
-	}
 
 	ret = enable_irq_wake(fsl_wakeup->timer->irq);
 	if (ret) {
 		mpic_free_timer(fsl_wakeup->timer);
 		fsl_wakeup->timer = NULL;
-		mutex_unlock(&sysfs_lock);
-
 		return ret;
 	}
 
 	mpic_start_timer(fsl_wakeup->timer);
 
-	mutex_unlock(&sysfs_lock);
-
 	return count;
 }
 
-- 
2.39.3