mac80211: Optimize scans on current operating channel.
This should decrease un-necessary flushes, on/off channel work,
and channel changes in cases where the only scanned channel is
the current operating channel.
* Removes SCAN_OFF_CHANNEL flag, uses SDATA_STATE_OFFCHANNEL
and is-scanning flags instead.
* Add helper method to determine if we are currently configured
for the operating channel.
* Do no blindly go off/on channel in work.c Instead, only call
appropriate on/off code when we really need to change channels.
Always enable offchannel-ps mode when starting work,
and disable it when we are done.
* Consolidate ieee80211_offchannel_stop_station and
ieee80211_offchannel_stop_beaconing, call it
ieee80211_offchannel_stop_vifs instead.
* Accept non-beacon frames when scanning on operating channel.
* Scan state machine optimized to minimize on/off channel
transitions. Also, when going on-channel, go ahead and
re-enable beaconing. We're going to be there for 200ms,
so seems like some useful beaconing could happen.
Always enable offchannel-ps mode when starting software
scan, and disable it when we are done.
* Grab local->mtx earlier in __ieee80211_scan_completed_finish
so that we are protected when calling hw_config(), etc.
* Pass probe-responses up the stack if scanning on local
channel, so that mlme can take a look.
Signed-off-by: Ben Greear <greearb@candelatech.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
diff --git a/net/mac80211/work.c b/net/mac80211/work.c
index 36305e0..6bf787a 100644
--- a/net/mac80211/work.c
+++ b/net/mac80211/work.c
@@ -924,18 +924,44 @@
}
if (!started && !local->tmp_channel) {
- /*
- * TODO: could optimize this by leaving the
- * station vifs in awake mode if they
- * happen to be on the same channel as
- * the requested channel
- */
- ieee80211_offchannel_stop_beaconing(local);
- ieee80211_offchannel_stop_station(local);
+ bool on_oper_chan;
+ bool tmp_chan_changed = false;
+ bool on_oper_chan2;
+ on_oper_chan = ieee80211_cfg_on_oper_channel(local);
+ if (local->tmp_channel)
+ if ((local->tmp_channel != wk->chan) ||
+ (local->tmp_channel_type != wk->chan_type))
+ tmp_chan_changed = true;
local->tmp_channel = wk->chan;
local->tmp_channel_type = wk->chan_type;
- ieee80211_hw_config(local, 0);
+ /*
+ * Leave the station vifs in awake mode if they
+ * happen to be on the same channel as
+ * the requested channel.
+ */
+ on_oper_chan2 = ieee80211_cfg_on_oper_channel(local);
+ if (on_oper_chan != on_oper_chan2) {
+ if (on_oper_chan2) {
+ /* going off oper channel, PS too */
+ ieee80211_offchannel_stop_vifs(local,
+ true);
+ ieee80211_hw_config(local, 0);
+ } else {
+ /* going on channel, but leave PS
+ * off-channel. */
+ ieee80211_hw_config(local, 0);
+ ieee80211_offchannel_return(local,
+ true,
+ false);
+ }
+ } else if (tmp_chan_changed)
+ /* Still off-channel, but on some other
+ * channel, so update hardware.
+ * PS should already be off-channel.
+ */
+ ieee80211_hw_config(local, 0);
+
started = true;
wk->timeout = jiffies;
}
@@ -1011,9 +1037,27 @@
}
if (!remain_off_channel && local->tmp_channel) {
+ bool on_oper_chan = ieee80211_cfg_on_oper_channel(local);
local->tmp_channel = NULL;
- ieee80211_hw_config(local, 0);
- ieee80211_offchannel_return(local, true);
+ /* If tmp_channel wasn't operating channel, then
+ * we need to go back on-channel.
+ * NOTE: If we can ever be here while scannning,
+ * or if the hw_config() channel config logic changes,
+ * then we may need to do a more thorough check to see if
+ * we still need to do a hardware config. Currently,
+ * we cannot be here while scanning, however.
+ */
+ if (ieee80211_cfg_on_oper_channel(local) && !on_oper_chan)
+ ieee80211_hw_config(local, 0);
+
+ /* At the least, we need to disable offchannel_ps,
+ * so just go ahead and run the entire offchannel
+ * return logic here. We *could* skip enabling
+ * beaconing if we were already on-oper-channel
+ * as a future optimization.
+ */
+ ieee80211_offchannel_return(local, true, true);
+
/* give connection some time to breathe */
run_again(local, jiffies + HZ/2);
}