Input: cm109 - use guard notation when acquiring mutex and spinlock

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.

Reviewed-by: Javier Carrasco <[e-mail]>
Link: https://lore.kernel.org/r/[e-mail]
Signed-off-by: Dmitry Torokhov <[e-mail]>

drivers/input/misc/cm109.c

···
 			__func__, error);
 }
 
+static void cm109_submit_ctl(struct cm109_dev *dev)
+{
+	int error;
+
+	guard(spinlock_irqsave)(&dev->ctl_submit_lock);
+
+	dev->irq_urb_pending = 0;
+
+	if (unlikely(dev->shutdown))
+		return;
+
+	if (dev->buzzer_state)
+		dev->ctl_data->byte[HID_OR0] |= BUZZER_ON;
+	else
+		dev->ctl_data->byte[HID_OR0] &= ~BUZZER_ON;
+
+	dev->ctl_data->byte[HID_OR1] = dev->keybit;
+	dev->ctl_data->byte[HID_OR2] = dev->keybit;
+
+	dev->buzzer_pending = 0;
+	dev->ctl_urb_pending = 1;
+
+	error = usb_submit_urb(dev->urb_ctl, GFP_ATOMIC);
+	if (error)
+		dev_err(&dev->intf->dev,
+			"%s: usb_submit_urb (urb_ctl) failed %d\n",
+			__func__, error);
+}
+
 /*
  * IRQ handler
  */
···
 {
 	struct cm109_dev *dev = urb->context;
 	const int status = urb->status;
-	int error;
-	unsigned long flags;
 
 	dev_dbg(&dev->intf->dev, "### URB IRQ: [0x%02x 0x%02x 0x%02x 0x%02x] keybit=0x%02x\n",
 	     dev->irq_data->byte[0],
···
 	}
 
  out:
-
-	spin_lock_irqsave(&dev->ctl_submit_lock, flags);
-
-	dev->irq_urb_pending = 0;
-
-	if (likely(!dev->shutdown)) {
-
-		if (dev->buzzer_state)
-			dev->ctl_data->byte[HID_OR0] |= BUZZER_ON;
-		else
-			dev->ctl_data->byte[HID_OR0] &= ~BUZZER_ON;
-
-		dev->ctl_data->byte[HID_OR1] = dev->keybit;
-		dev->ctl_data->byte[HID_OR2] = dev->keybit;
-
-		dev->buzzer_pending = 0;
-		dev->ctl_urb_pending = 1;
-
-		error = usb_submit_urb(dev->urb_ctl, GFP_ATOMIC);
-		if (error)
-			dev_err(&dev->intf->dev,
-				"%s: usb_submit_urb (urb_ctl) failed %d\n",
-				__func__, error);
-	}
-
-	spin_unlock_irqrestore(&dev->ctl_submit_lock, flags);
+	cm109_submit_ctl(dev);
 }
 
 static void cm109_urb_ctl_callback(struct urb *urb)
···
 	struct cm109_dev *dev = urb->context;
 	const int status = urb->status;
 	int error;
-	unsigned long flags;
 
 	dev_dbg(&dev->intf->dev, "### URB CTL: [0x%02x 0x%02x 0x%02x 0x%02x]\n",
 	     dev->ctl_data->byte[0],
···
 				    __func__, status);
 	}
 
-	spin_lock_irqsave(&dev->ctl_submit_lock, flags);
+	guard(spinlock_irqsave)(&dev->ctl_submit_lock);
 
 	dev->ctl_urb_pending = 0;
 
-	if (likely(!dev->shutdown)) {
+	if (unlikely(dev->shutdown))
+		return;
 
-		if (dev->buzzer_pending || status) {
-			dev->buzzer_pending = 0;
-			dev->ctl_urb_pending = 1;
-			cm109_submit_buzz_toggle(dev);
-		} else if (likely(!dev->irq_urb_pending)) {
-			/* ask for key data */
-			dev->irq_urb_pending = 1;
-			error = usb_submit_urb(dev->urb_irq, GFP_ATOMIC);
-			if (error)
-				dev_err(&dev->intf->dev,
-					"%s: usb_submit_urb (urb_irq) failed %d\n",
-					__func__, error);
-		}
+	if (dev->buzzer_pending || status) {
+		dev->buzzer_pending = 0;
+		dev->ctl_urb_pending = 1;
+		cm109_submit_buzz_toggle(dev);
+	} else if (likely(!dev->irq_urb_pending)) {
+		/* ask for key data */
+		dev->irq_urb_pending = 1;
+		error = usb_submit_urb(dev->urb_irq, GFP_ATOMIC);
+		if (error)
+			dev_err(&dev->intf->dev,
+				"%s: usb_submit_urb (urb_irq) failed %d\n",
+				__func__, error);
 	}
-
-	spin_unlock_irqrestore(&dev->ctl_submit_lock, flags);
 }
 
 static void cm109_toggle_buzzer_async(struct cm109_dev *dev)
 {
-	unsigned long flags;
-
-	spin_lock_irqsave(&dev->ctl_submit_lock, flags);
+	guard(spinlock_irqsave)(&dev->ctl_submit_lock);
 
 	if (dev->ctl_urb_pending) {
 		/* URB completion will resubmit */
···
 		dev->ctl_urb_pending = 1;
 		cm109_submit_buzz_toggle(dev);
 	}
-
-	spin_unlock_irqrestore(&dev->ctl_submit_lock, flags);
 }
 
 static void cm109_toggle_buzzer_sync(struct cm109_dev *dev, int on)
···
 		return error;
 	}
 
-	mutex_lock(&dev->pm_mutex);
+	scoped_guard(mutex, &dev->pm_mutex) {
+		dev->buzzer_state = 0;
+		dev->key_code = -1;	/* no keys pressed */
+		dev->keybit = 0xf;
 
-	dev->buzzer_state = 0;
-	dev->key_code = -1;	/* no keys pressed */
-	dev->keybit = 0xf;
+		/* issue INIT */
+		dev->ctl_data->byte[HID_OR0] = HID_OR_GPO_BUZ_SPDIF;
+		dev->ctl_data->byte[HID_OR1] = dev->keybit;
+		dev->ctl_data->byte[HID_OR2] = dev->keybit;
+		dev->ctl_data->byte[HID_OR3] = 0x00;
 
-	/* issue INIT */
-	dev->ctl_data->byte[HID_OR0] = HID_OR_GPO_BUZ_SPDIF;
-	dev->ctl_data->byte[HID_OR1] = dev->keybit;
-	dev->ctl_data->byte[HID_OR2] = dev->keybit;
-	dev->ctl_data->byte[HID_OR3] = 0x00;
-
-	dev->ctl_urb_pending = 1;
-	error = usb_submit_urb(dev->urb_ctl, GFP_KERNEL);
-	if (error) {
-		dev->ctl_urb_pending = 0;
-		dev_err(&dev->intf->dev, "%s: usb_submit_urb (urb_ctl) failed %d\n",
-			__func__, error);
-	} else {
-		dev->open = 1;
+		dev->ctl_urb_pending = 1;
+		error = usb_submit_urb(dev->urb_ctl, GFP_KERNEL);
+		if (!error) {
+			dev->open = 1;
+			return 0;
+		}
 	}
 
-	mutex_unlock(&dev->pm_mutex);
+	dev->ctl_urb_pending = 0;
+	usb_autopm_put_interface(dev->intf);
 
-	if (error)
-		usb_autopm_put_interface(dev->intf);
+	dev_err(&dev->intf->dev, "%s: usb_submit_urb (urb_ctl) failed %d\n",
+		__func__, error);
 
 	return error;
 }
···
 {
 	struct cm109_dev *dev = input_get_drvdata(idev);
 
-	mutex_lock(&dev->pm_mutex);
-
-	/*
-	 * Once we are here event delivery is stopped so we
-	 * don't need to worry about someone starting buzzer
-	 * again
-	 */
-	cm109_stop_traffic(dev);
-	dev->open = 0;
-
-	mutex_unlock(&dev->pm_mutex);
+	scoped_guard(mutex, &dev->pm_mutex) {
+		/*
+		 * Once we are here event delivery is stopped so we
+		 * don't need to worry about someone starting buzzer
+		 * again
+		 */
+		cm109_stop_traffic(dev);
+		dev->open = 0;
+	}
 
 	usb_autopm_put_interface(dev->intf);
 }
···
 
 	dev_info(&intf->dev, "cm109: usb_suspend (event=%d)\n", message.event);
 
-	mutex_lock(&dev->pm_mutex);
+	guard(mutex)(&dev->pm_mutex);
+
 	cm109_stop_traffic(dev);
-	mutex_unlock(&dev->pm_mutex);
 
 	return 0;
 }
···
 
 	dev_info(&intf->dev, "cm109: usb_resume\n");
 
-	mutex_lock(&dev->pm_mutex);
+	guard(mutex)(&dev->pm_mutex);
+
 	cm109_restore_state(dev);
-	mutex_unlock(&dev->pm_mutex);
 
 	return 0;
 }