[PATCH 11/24] Input: hyperv-keyboard - use guard notation when acquiring spinlock

[Dmitry Torokhov]

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.torok...@gmail.com>
---
 drivers/input/serio/hyperv-keyboard.c | 38 +++++++++++++--------------
 1 file changed, 18 insertions(+), 20 deletions(-)

diff --git a/drivers/input/serio/hyperv-keyboard.c 
b/drivers/input/serio/hyperv-keyboard.c
index 31d9dacd2fd1..0ee7505427ac 100644
--- a/drivers/input/serio/hyperv-keyboard.c
+++ b/drivers/input/serio/hyperv-keyboard.c
@@ -102,7 +102,6 @@ static void hv_kbd_on_receive(struct hv_device *hv_dev,
 {
        struct hv_kbd_dev *kbd_dev = hv_get_drvdata(hv_dev);
        struct synth_kbd_keystroke *ks_msg;
-       unsigned long flags;
        u32 msg_type = __le32_to_cpu(msg->header.type);
        u32 info;
        u16 scan_code;
@@ -147,21 +146,22 @@ static void hv_kbd_on_receive(struct hv_device *hv_dev,
                /*
                 * Inject the information through the serio interrupt.
                 */
-               spin_lock_irqsave(&kbd_dev->lock, flags);
-               if (kbd_dev->started) {
-                       if (info & IS_E0)
-                               serio_interrupt(kbd_dev->hv_serio,
-                                               XTKBD_EMUL0, 0);
-                       if (info & IS_E1)
-                               serio_interrupt(kbd_dev->hv_serio,
-                                               XTKBD_EMUL1, 0);
-                       scan_code = __le16_to_cpu(ks_msg->make_code);
-                       if (info & IS_BREAK)
-                               scan_code |= XTKBD_RELEASE;
+               scoped_guard(spinlock_irqsave, &kbd_dev->lock) {
+                       if (kbd_dev->started) {
+                               if (info & IS_E0)
+                                       serio_interrupt(kbd_dev->hv_serio,
+                                                       XTKBD_EMUL0, 0);
+                               if (info & IS_E1)
+                                       serio_interrupt(kbd_dev->hv_serio,
+                                                       XTKBD_EMUL1, 0);
+                               scan_code = __le16_to_cpu(ks_msg->make_code);
+                               if (info & IS_BREAK)
+                                       scan_code |= XTKBD_RELEASE;
 
-                       serio_interrupt(kbd_dev->hv_serio, scan_code, 0);
+                               serio_interrupt(kbd_dev->hv_serio,
+                                               scan_code, 0);
+                       }
                }
-               spin_unlock_irqrestore(&kbd_dev->lock, flags);
 
                /*
                 * Only trigger a wakeup on key down, otherwise
@@ -292,11 +292,10 @@ static int hv_kbd_connect_to_vsp(struct hv_device *hv_dev)
 static int hv_kbd_start(struct serio *serio)
 {
        struct hv_kbd_dev *kbd_dev = serio->port_data;
-       unsigned long flags;
 
-       spin_lock_irqsave(&kbd_dev->lock, flags);
+       guard(spinlock_irqsave)(&kbd_dev->lock);
+
        kbd_dev->started = true;
-       spin_unlock_irqrestore(&kbd_dev->lock, flags);
 
        return 0;
 }
@@ -304,11 +303,10 @@ static int hv_kbd_start(struct serio *serio)
 static void hv_kbd_stop(struct serio *serio)
 {
        struct hv_kbd_dev *kbd_dev = serio->port_data;
-       unsigned long flags;
 
-       spin_lock_irqsave(&kbd_dev->lock, flags);
+       guard(spinlock_irqsave)(&kbd_dev->lock);
+
        kbd_dev->started = false;
-       spin_unlock_irqrestore(&kbd_dev->lock, flags);
 }
 
 static int hv_kbd_probe(struct hv_device *hv_dev,
-- 
2.46.0.469.g59c65b2a67-goog