Commit eab48345 authored by Vitaly Wool's avatar Vitaly Wool Committed by Johannes Berg
Browse files

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: default avatarVitaly Wool <vitalywool@gmail.com>
Signed-off-by: default avatarMykyta Iziumtsev <nikita.izyumtsev@gmail.com>
Signed-off-by: default avatarJohannes Berg <johannes.berg@intel.com>
parent c6f219dc

net/rfkill/core.c

+7 −1
Original line number Diff line number Diff line
@@ -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
@@ -313,9 +316,12 @@ 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);



	if (prev != curr)

		rfkill_event(rfkill);

}

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