[PATCH v2 28/33] HID: logitech-hidpp: use guard() for send_mutex

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

Manual mutex_lock() and mutex_unlock() calls force early loop exits to
break to a shared unlock path instead of returning directly. Convert
hidpp_send_message_sync() to use guard(mutex) so lock release is bound
to the function scope and busy-retry exits can return immediately.

Tested-by: Gideon Heinz <gideonheinz02@gmail.com>
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
---
 drivers/hid/hid-logitech-hidpp.c | 6 ++----
 1 file changed, 2 insertions(+), 4 deletions(-)

diff --git a/drivers/hid/hid-logitech-hidpp.c b/drivers/hid/hid-logitech-hidpp.c
index 181b791b3e0c..8f2a9d3e0f74 100644
--- a/drivers/hid/hid-logitech-hidpp.c
+++ b/drivers/hid/hid-logitech-hidpp.c
@@ -380,19 +380,17 @@ static int hidpp_send_message_sync(struct hidpp_device *hidpp,
 	int ret;
 	int max_retries = 3;
 
-	mutex_lock(&hidpp->send_mutex);
+	guard(mutex)(&hidpp->send_mutex);
 
 	do {
 		ret = __do_hidpp_send_message_sync(hidpp, message, response);
 		if (ret != -EBUSY)
-			break;
+			return ret;
 
 		dbg_hid("%s:got busy hidpp error, retrying\n", __func__);
 	} while (--max_retries);
 
-	mutex_unlock(&hidpp->send_mutex);
 	return ret;
-
 }
 
 /*

-- 
2.56.0.542.g3ef89b7020-goog