rc: ir-raw: change type of available_protocols to atomic64_t

Commit Message

Heiner Kallweit Sept. 27, 2016, 7:48 p.m. UTC

Changing available_protocols to atomic64_t allows to get rid of the
mutex protecting access to the variable. This helps to simplify
the code.

Signed-off-by: Heiner Kallweit <[e-mail]>
---
 drivers/media/rc/rc-ir-raw.c | 17 ++++-------------
 1 file changed, 4 insertions(+), 13 deletions(-)

Patch

diff --git a/drivers/media/rc/rc-ir-raw.c b/drivers/media/rc/rc-ir-raw.c
index 205ecc6..1c42a9f 100644
--- a/drivers/media/rc/rc-ir-raw.c
+++ b/drivers/media/rc/rc-ir-raw.c
@@ -26,8 +26,7 @@  static LIST_HEAD(ir_raw_client_list);
 /* Used to handle IR raw handler extensions */
 static DEFINE_MUTEX(ir_raw_handler_lock);
 static LIST_HEAD(ir_raw_handler_list);
-static DEFINE_MUTEX(available_protocols_lock);
-static u64 available_protocols;
+static atomic64_t available_protocols = ATOMIC64_INIT(0);
 
 static int ir_raw_event_thread(void *data)
 {
@@ -234,11 +233,7 @@  EXPORT_SYMBOL_GPL(ir_raw_event_handle);
 u64
 ir_raw_get_allowed_protocols(void)
 {
-	u64 protocols;
-	mutex_lock(&available_protocols_lock);
-	protocols = available_protocols;
-	mutex_unlock(&available_protocols_lock);
-	return protocols;
+	return atomic64_read(&available_protocols);
 }
 
 static int change_protocol(struct rc_dev *dev, u64 *rc_type)
@@ -331,9 +326,7 @@  int ir_raw_handler_register(struct ir_raw_handler *ir_raw_handler)
 	if (ir_raw_handler->raw_register)
 		list_for_each_entry(raw, &ir_raw_client_list, list)
 			ir_raw_handler->raw_register(raw->dev);
-	mutex_lock(&available_protocols_lock);
-	available_protocols |= ir_raw_handler->protocols;
-	mutex_unlock(&available_protocols_lock);
+	atomic64_or(ir_raw_handler->protocols, &available_protocols);
 	mutex_unlock(&ir_raw_handler_lock);
 
 	return 0;
@@ -352,9 +345,7 @@  void ir_raw_handler_unregister(struct ir_raw_handler *ir_raw_handler)
 		if (ir_raw_handler->raw_unregister)
 			ir_raw_handler->raw_unregister(raw->dev);
 	}
-	mutex_lock(&available_protocols_lock);
-	available_protocols &= ~protocols;
-	mutex_unlock(&available_protocols_lock);
+	atomic64_andnot(protocols, &available_protocols);
 	mutex_unlock(&ir_raw_handler_lock);
 }
 EXPORT_SYMBOL(ir_raw_handler_unregister);