From eab48345c2b2d791159aaac4a77000baa8dbc1ae Mon Sep 17 00:00:00 2001 From: Vitaly Wool Date: Thu, 6 Sep 2012 16:06:52 +0200 Subject: rfkill: prevent unnecessary event generation Prevent unnecessary rfkill event generation when the state has not actually changed. These events have to be delivered to relevant userspace processes, causing these processes to wake up and do something while they could as well have slept. This obviously results in more CPU usage, longer time-to-sleep-again and therefore higher power consumption. Signed-off-by: Vitaly Wool Signed-off-by: Mykyta Iziumtsev Signed-off-by: Johannes Berg --- net/rfkill/core.c | 8 +++++++- 1 file changed, 7 insertions(+), 1 deletion(-) diff --git a/net/rfkill/core.c b/net/rfkill/core.c index c275bad12068..a5c952741279 100644 --- a/net/rfkill/core.c +++ b/net/rfkill/core.c @@ -270,6 +270,7 @@ static bool __rfkill_set_hw_state(struct rfkill *rfkill, static void rfkill_set_block(struct rfkill *rfkill, bool blocked) { unsigned long flags; + bool prev, curr; int err; if (unlikely(rfkill->dev.power.power_state.event & PM_EVENT_SLEEP)) @@ -284,6 +285,8 @@ static void rfkill_set_block(struct rfkill *rfkill, bool blocked) rfkill->ops->query(rfkill, rfkill->data); spin_lock_irqsave(&rfkill->lock, flags); + prev = rfkill->state & RFKILL_BLOCK_SW; + if (rfkill->state & RFKILL_BLOCK_SW) rfkill->state |= RFKILL_BLOCK_SW_PREV; else @@ -313,10 +316,13 @@ static void rfkill_set_block(struct rfkill *rfkill, bool blocked) } rfkill->state &= ~RFKILL_BLOCK_SW_SETCALL; rfkill->state &= ~RFKILL_BLOCK_SW_PREV; + curr = rfkill->state & RFKILL_BLOCK_SW; spin_unlock_irqrestore(&rfkill->lock, flags); rfkill_led_trigger_event(rfkill); - rfkill_event(rfkill); + + if (prev != curr) + rfkill_event(rfkill); } #ifdef CONFIG_RFKILL_INPUT -- cgit v1.2.3