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Input: bcm5974 - use guard notation when acquiring mutex

PATCH In review Dmitry Torokhov 3 participants 3 messages Aug 25, 2024

Subsystems (3)
HID Input drivers Apple BCM5974 multitouch driver
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Dmitry Torokhov

author maintainer
#0 lore raw

PATCH 1/1 Input: bcm5974 - use guard notation when acquiring mutex

This 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 <[email protected]>
---
 drivers/input/mouse/bcm5974.c | 35 +++++++++++++----------------------
 1 file changed, 13 insertions(+), 22 deletions(-)
drivers/input/mouse/bcm5974.c +13 -22
index 10a03a566905..dfdfb59cc8b5 100644
@@ -834,13 +834,11 @@ static int bcm5974_open(struct input_dev *input)
 	if (error)
 		return error;
 
-	mutex_lock(&dev->pm_mutex);
-
-	error = bcm5974_start_traffic(dev);
-	if (!error)
-		dev->opened = 1;
-
-	mutex_unlock(&dev->pm_mutex);
+	scoped_guard(mutex, &dev->pm_mutex) {
+		error = bcm5974_start_traffic(dev);
+		if (!error)
+			dev->opened = 1;
+	}
 
 	if (error)
 		usb_autopm_put_interface(dev->intf);

@@ -852,12 +850,10 @@ static void bcm5974_close(struct input_dev *input)
 {
 	struct bcm5974 *dev = input_get_drvdata(input);
 
-	mutex_lock(&dev->pm_mutex);
-
-	bcm5974_pause_traffic(dev);
-	dev->opened = 0;
-
-	mutex_unlock(&dev->pm_mutex);
+	scoped_guard(mutex, &dev->pm_mutex) {
+		bcm5974_pause_traffic(dev);
+		dev->opened = 0;
+	}
 
 	usb_autopm_put_interface(dev->intf);
 }

@@ -866,29 +862,24 @@ static int bcm5974_suspend(struct usb_interface *iface, pm_message_t message)
 {
 	struct bcm5974 *dev = usb_get_intfdata(iface);
 
-	mutex_lock(&dev->pm_mutex);
+	guard(mutex)(&dev->pm_mutex);
 
 	if (dev->opened)
 		bcm5974_pause_traffic(dev);
 
-	mutex_unlock(&dev->pm_mutex);
-
 	return 0;
 }
 
 static int bcm5974_resume(struct usb_interface *iface)
 {
 	struct bcm5974 *dev = usb_get_intfdata(iface);
-	int error = 0;
 
-	mutex_lock(&dev->pm_mutex);
+	guard(mutex)(&dev->pm_mutex);
 
 	if (dev->opened)
-		error = bcm5974_start_traffic(dev);
+		return bcm5974_start_traffic(dev);
 
-	mutex_unlock(&dev->pm_mutex);
-
-	return error;
+	return 0;
 }
 
 static int bcm5974_probe(struct usb_interface *iface,
Signature · 5 lines
2.46.0.295.g3b9ea8a38a-goog


-- 
Dmitry
Acked-by Henrik Rydberg on v1 1/1
#1 lore raw
Quoted 9 lines · Dmitry Torokhov

This 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 <[email protected]>
---
 drivers/input/mouse/bcm5974.c | 35 +++++++++++++----------------------
 1 file changed, 13 insertions(+), 22 deletions(-)

Thanks Dmitry,

Acked-by Henrik Rydberg <[email protected]>