[PATCH 02/24] Input: libps2 - use guard notation when temporarily pausing serio ports

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

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

Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
---
 drivers/input/serio/libps2.c | 28 +++++++++++++++-------------
 1 file changed, 15 insertions(+), 13 deletions(-)

diff --git a/drivers/input/serio/libps2.c b/drivers/input/serio/libps2.c
index 6d78a1fe00c1..c22ea532276e 100644
--- a/drivers/input/serio/libps2.c
+++ b/drivers/input/serio/libps2.c
@@ -108,13 +108,11 @@ int ps2_sendbyte(struct ps2dev *ps2dev, u8 byte, unsigned int timeout)
 {
 	int retval;
 
-	serio_pause_rx(ps2dev->serio);
+	guard(serio_pause_rx)(ps2dev->serio);
 
 	retval = ps2_do_sendbyte(ps2dev, byte, timeout, 1);
 	dev_dbg(&ps2dev->serio->dev, "%02x - %x\n", byte, ps2dev->nak);
 
-	serio_continue_rx(ps2dev->serio);
-
 	return retval;
 }
 EXPORT_SYMBOL(ps2_sendbyte);
@@ -162,10 +160,10 @@ void ps2_drain(struct ps2dev *ps2dev, size_t maxbytes, unsigned int timeout)
 
 	ps2_begin_command(ps2dev);
 
-	serio_pause_rx(ps2dev->serio);
-	ps2dev->flags = PS2_FLAG_CMD;
-	ps2dev->cmdcnt = maxbytes;
-	serio_continue_rx(ps2dev->serio);
+	scoped_guard(serio_pause_rx, ps2dev->serio) {
+		ps2dev->flags = PS2_FLAG_CMD;
+		ps2dev->cmdcnt = maxbytes;
+	}
 
 	wait_event_timeout(ps2dev->wait,
 			   !(ps2dev->flags & PS2_FLAG_CMD),
@@ -224,9 +222,9 @@ static int ps2_adjust_timeout(struct ps2dev *ps2dev,
 		 * use alternative probe to detect it.
 		 */
 		if (ps2dev->cmdbuf[1] == 0xaa) {
-			serio_pause_rx(ps2dev->serio);
-			ps2dev->flags = 0;
-			serio_continue_rx(ps2dev->serio);
+			scoped_guard(serio_pause_rx, ps2dev->serio)
+				ps2dev->flags = 0;
+
 			timeout = 0;
 		}
 
@@ -235,9 +233,9 @@ static int ps2_adjust_timeout(struct ps2dev *ps2dev,
 		 * won't be 2nd byte of ID response.
 		 */
 		if (!ps2_is_keyboard_id(ps2dev->cmdbuf[1])) {
-			serio_pause_rx(ps2dev->serio);
-			ps2dev->flags = ps2dev->cmdcnt = 0;
-			serio_continue_rx(ps2dev->serio);
+			scoped_guard(serio_pause_rx, ps2dev->serio)
+				ps2dev->flags = ps2dev->cmdcnt = 0;
+
 			timeout = 0;
 		}
 		break;
@@ -283,6 +281,10 @@ int __ps2_command(struct ps2dev *ps2dev, u8 *param, unsigned int command)
 
 	memcpy(send_param, param, send);
 
+	/*
+	 * Not using guard notation because we need to break critical
+	 * section below while waiting for the response.
+	 */
 	serio_pause_rx(ps2dev->serio);
 
 	ps2dev->cmdcnt = receive;
-- 
2.46.0.469.g59c65b2a67-goog