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authorVitaly Wool <vitaly.wool@sonymobile.com>2012-09-06 16:06:52 +0200
committerJohannes Berg <johannes.berg@intel.com>2012-09-24 10:35:54 +0200
commiteab48345c2b2d791159aaac4a77000baa8dbc1ae (patch)
tree7ea44540a71f3dd482441b458ae4127f055a14c3
parentc6f219dc83fbb30c8426fcc7850c28d9d33dee44 (diff)
downloadblackbird-op-linux-eab48345c2b2d791159aaac4a77000baa8dbc1ae.tar.gz
blackbird-op-linux-eab48345c2b2d791159aaac4a77000baa8dbc1ae.zip
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 <vitalywool@gmail.com> Signed-off-by: Mykyta Iziumtsev <nikita.izyumtsev@gmail.com> Signed-off-by: Johannes Berg <johannes.berg@intel.com>
-rw-r--r--net/rfkill/core.c8
1 files changed, 7 insertions, 1 deletions
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
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