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

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Message-ID: <20240905041732.2034348-12-dmitry.torokhov@gmail.com>
Date: Wed,  4 Sep 2024 21:17:16 -0700
From: Dmitry Torokhov <dmitry.torokhov@...il.com>
To: linux-input@...r.kernel.org
Cc: Pali Rohár <pali@...nel.org>,
	Helge Deller <deller@....de>,
	"K. Y. Srinivasan" <kys@...rosoft.com>,
	Wei Liu <wei.liu@...nel.org>,
	Dexuan Cui <decui@...rosoft.com>,
	Samuel Holland <samuel@...lland.org>,
	Lyude Paul <thatslyude@...il.com>,
	Michal Simek <michal.simek@....com>,
	Hans de Goede <hdegoede@...hat.com>,
	linux-kernel@...r.kernel.org,
	linux-hyperv@...r.kernel.org,
	linux-arm-kernel@...ts.infradead.org,
	linux-sunxi@...ts.linux.dev
Subject: [PATCH 11/24] Input: hyperv-keyboard - use guard notation when acquiring 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.

Signed-off-by: Dmitry Torokhov <dmitry.torokhov@...il.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