rfkill: document the rfkill struct locking (v2)
Reorder fields in struct rfkill and add comments to make it clear
which fields are protected by rfkill->mutex.
Signed-off-by: Henrique de Moraes Holschuh <hmh@hmh.eng.br>
Acked-by: Ivo van Doorn <IvDoorn@gmail.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
diff --git a/include/linux/rfkill.h b/include/linux/rfkill.h
index c5f6e54..741d1a6 100644
--- a/include/linux/rfkill.h
+++ b/include/linux/rfkill.h
@@ -68,7 +68,8 @@
* @user_claim_unsupported: Whether the hardware supports exclusive
* RF-kill control by userspace. Set this before registering.
* @user_claim: Set when the switch is controlled exlusively by userspace.
- * @mutex: Guards switch state transitions
+ * @mutex: Guards switch state transitions. It serializes callbacks
+ * and also protects the state.
* @data: Pointer to the RF button drivers private data which will be
* passed along when toggling radio state.
* @toggle_radio(): Mandatory handler to control state of the radio.
@@ -89,12 +90,13 @@
const char *name;
enum rfkill_type type;
- enum rfkill_state state;
bool user_claim_unsupported;
bool user_claim;
+ /* the mutex serializes callbacks and also protects
+ * the state */
struct mutex mutex;
-
+ enum rfkill_state state;
void *data;
int (*toggle_radio)(void *data, enum rfkill_state state);
int (*get_state)(void *data, enum rfkill_state *state);