| Message ID | 20140403233448.27099.69654.stgit@zeus.muc.hardeman.nu (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
Em Fri, 04 Apr 2014 01:34:48 +0200 David Härdeman <david@hardeman.nu> 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@hardeman.nu> > --- > 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(); > } > > -- > To unsubscribe from this list: send the line "unsubscribe linux-media" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html -- To unsubscribe from this list: send the line "unsubscribe linux-media" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
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(); }
Use atomic reads to avoid having to take a mutex when getting the bitmask of supported protocols. Signed-off-by: David Härdeman <david@hardeman.nu> --- drivers/media/rc/rc-core-priv.h | 2 +- drivers/media/rc/rc-ir-raw.c | 12 ++++-------- 2 files changed, 5 insertions(+), 9 deletions(-) -- To unsubscribe from this list: send the line "unsubscribe linux-media" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html