Em Fri, 04 Apr 2014 01:34:48 +0200
David Härdeman <david@xxxxxxxxxxx> escreveu:
> Use atomic reads to avoid having to take a mutex when getting
> the bitmask of supported protocols.
This also belongs to that RCU change series, and doesn't apply.
>
> Signed-off-by: David Härdeman <david@xxxxxxxxxxx>
> ---
> drivers/media/rc/rc-core-priv.h | 2 +-
> drivers/media/rc/rc-ir-raw.c | 12 ++++--------
> 2 files changed, 5 insertions(+), 9 deletions(-)
>
> diff --git a/drivers/media/rc/rc-core-priv.h b/drivers/media/rc/rc-core-priv.h
> index c3de26b..04776e8 100644
> --- a/drivers/media/rc/rc-core-priv.h
> +++ b/drivers/media/rc/rc-core-priv.h
> @@ -29,7 +29,7 @@ enum rc_driver_type {
> struct ir_raw_handler {
> struct list_head list;
>
> - u64 protocols; /* which are handled by this handler */
> + unsigned protocols; /* which are handled by this handler */
> int (*decode)(struct rc_dev *dev, struct ir_raw_event event);
>
> /* These two should only be used by the lirc decoder */
> diff --git a/drivers/media/rc/rc-ir-raw.c b/drivers/media/rc/rc-ir-raw.c
> index 9631825..bf5215b 100644
> --- a/drivers/media/rc/rc-ir-raw.c
> +++ b/drivers/media/rc/rc-ir-raw.c
> @@ -27,7 +27,7 @@ static LIST_HEAD(ir_raw_client_list);
> static LIST_HEAD(ir_raw_handler_list);
>
> /* protocols supported by the currently loaded decoders */
> -static u64 available_protocols;
> +static atomic_t available_protocols = ATOMIC_INIT(0);
>
> static int ir_raw_event_thread(void *data)
> {
> @@ -251,11 +251,7 @@ EXPORT_SYMBOL_GPL(ir_raw_event_handle);
> /* used internally by the sysfs interface */
> static u64 ir_raw_get_allowed_protocols(struct rc_dev *dev)
> {
> - u64 protocols;
> - mutex_lock(&ir_raw_mutex);
> - protocols = available_protocols;
> - mutex_unlock(&ir_raw_mutex);
> - return protocols;
> + return atomic_read(&available_protocols);
> }
>
> static int change_protocol(struct rc_dev *dev, u64 *rc_type) {
> @@ -353,7 +349,7 @@ int ir_raw_handler_register(struct ir_raw_handler *ir_raw_handler)
> if (ir_raw_handler->raw_register)
> list_for_each_entry_rcu(raw, &ir_raw_client_list, list)
> ir_raw_handler->raw_register(raw->dev);
> - available_protocols |= ir_raw_handler->protocols;
> + atomic_set_mask(ir_raw_handler->protocols, &available_protocols);
> mutex_unlock(&ir_raw_mutex);
> synchronize_rcu();
>
> @@ -370,7 +366,7 @@ void ir_raw_handler_unregister(struct ir_raw_handler *ir_raw_handler)
> if (ir_raw_handler->raw_unregister)
> list_for_each_entry_rcu(raw, &ir_raw_client_list, list)
> ir_raw_handler->raw_unregister(raw->dev);
> - available_protocols &= ~ir_raw_handler->protocols;
> + atomic_clear_mask(ir_raw_handler->protocols, &available_protocols);
> mutex_unlock(&ir_raw_mutex);
> synchronize_rcu();
> }
>
> --
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