[PATCH 18/24] Input: serport - use guard notation when acquiring spinlock

[Dmitry Torokhov <dmitry.torokhov@gmail.com>]

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

Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
---
 drivers/input/serio/serport.c | 27 ++++++++-------------------
 1 file changed, 8 insertions(+), 19 deletions(-)

diff --git a/drivers/input/serio/serport.c b/drivers/input/serio/serport.c
index 5a2b5404ffc2..74ac88796187 100644
--- a/drivers/input/serio/serport.c
+++ b/drivers/input/serio/serport.c
@@ -50,11 +50,9 @@ static int serport_serio_write(struct serio *serio, unsigned char data)
 static int serport_serio_open(struct serio *serio)
 {
 	struct serport *serport = serio->port_data;
-	unsigned long flags;
 
-	spin_lock_irqsave(&serport->lock, flags);
+	guard(spinlock_irqsave)(&serport->lock);
 	set_bit(SERPORT_ACTIVE, &serport->flags);
-	spin_unlock_irqrestore(&serport->lock, flags);
 
 	return 0;
 }
@@ -63,11 +61,9 @@ static int serport_serio_open(struct serio *serio)
 static void serport_serio_close(struct serio *serio)
 {
 	struct serport *serport = serio->port_data;
-	unsigned long flags;
 
-	spin_lock_irqsave(&serport->lock, flags);
+	guard(spinlock_irqsave)(&serport->lock);
 	clear_bit(SERPORT_ACTIVE, &serport->flags);
-	spin_unlock_irqrestore(&serport->lock, flags);
 }
 
 /*
@@ -118,14 +114,13 @@ static void serport_ldisc_receive(struct tty_struct *tty, const u8 *cp,
 				  const u8 *fp, size_t count)
 {
 	struct serport *serport = tty->disc_data;
-	unsigned long flags;
 	unsigned int ch_flags = 0;
 	int i;
 
-	spin_lock_irqsave(&serport->lock, flags);
+	guard(spinlock_irqsave)(&serport->lock);
 
 	if (!test_bit(SERPORT_ACTIVE, &serport->flags))
-		goto out;
+		return;
 
 	for (i = 0; i < count; i++) {
 		if (fp) {
@@ -146,9 +141,6 @@ static void serport_ldisc_receive(struct tty_struct *tty, const u8 *cp,
 
 		serio_interrupt(serport->serio, cp[i], ch_flags);
 	}
-
-out:
-	spin_unlock_irqrestore(&serport->lock, flags);
 }
 
 /*
@@ -246,11 +238,9 @@ static int serport_ldisc_compat_ioctl(struct tty_struct *tty,
 static void serport_ldisc_hangup(struct tty_struct *tty)
 {
 	struct serport *serport = tty->disc_data;
-	unsigned long flags;
 
-	spin_lock_irqsave(&serport->lock, flags);
-	set_bit(SERPORT_DEAD, &serport->flags);
-	spin_unlock_irqrestore(&serport->lock, flags);
+	scoped_guard(spinlock_irqsave, &serport->lock)
+		set_bit(SERPORT_DEAD, &serport->flags);
 
 	wake_up_interruptible(&serport->wait);
 }
@@ -258,12 +248,11 @@ static void serport_ldisc_hangup(struct tty_struct *tty)
 static void serport_ldisc_write_wakeup(struct tty_struct * tty)
 {
 	struct serport *serport = tty->disc_data;
-	unsigned long flags;
 
-	spin_lock_irqsave(&serport->lock, flags);
+	guard(spinlock_irqsave)(&serport->lock);
+
 	if (test_bit(SERPORT_ACTIVE, &serport->flags))
 		serio_drv_write_wakeup(serport->serio);
-	spin_unlock_irqrestore(&serport->lock, flags);
 }
 
 /*
-- 
2.46.0.469.g59c65b2a67-goog