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/scan.c b/net/mac80211/scan.c
index 1ef73be..0ea6ada 100644
--- a/net/mac80211/scan.c
+++ b/net/mac80211/scan.c
@@ -212,6 +212,14 @@
if (bss)
ieee80211_rx_bss_put(sdata->local, bss);
+ /* If we are on-operating-channel, and this packet is for the
+ * current channel, pass the pkt on up the stack so that
+ * the rest of the stack can make use of it.
+ */
+ if (ieee80211_cfg_on_oper_channel(sdata->local)
+ && (channel == sdata->local->oper_channel))
+ return RX_CONTINUE;
+
dev_kfree_skb(skb);
return RX_QUEUED;
}
@@ -293,15 +301,31 @@
bool was_hw_scan)
{
struct ieee80211_local *local = hw_to_local(hw);
-
- ieee80211_hw_config(local, IEEE80211_CONF_CHANGE_CHANNEL);
- if (!was_hw_scan) {
- ieee80211_configure_filter(local);
- drv_sw_scan_complete(local);
- ieee80211_offchannel_return(local, true);
- }
+ bool on_oper_chan;
+ bool enable_beacons = false;
mutex_lock(&local->mtx);
+ on_oper_chan = ieee80211_cfg_on_oper_channel(local);
+
+ if (was_hw_scan || !on_oper_chan) {
+ if (WARN_ON(local->scan_channel))
+ local->scan_channel = NULL;
+ ieee80211_hw_config(local, IEEE80211_CONF_CHANGE_CHANNEL);
+ }
+
+ if (!was_hw_scan) {
+ bool on_oper_chan2;
+ ieee80211_configure_filter(local);
+ drv_sw_scan_complete(local);
+ on_oper_chan2 = ieee80211_cfg_on_oper_channel(local);
+ /* We should always be on-channel at this point. */
+ WARN_ON(!on_oper_chan2);
+ if (on_oper_chan2 && (on_oper_chan != on_oper_chan2))
+ enable_beacons = true;
+
+ ieee80211_offchannel_return(local, enable_beacons, true);
+ }
+
ieee80211_recalc_idle(local);
mutex_unlock(&local->mtx);
@@ -341,13 +365,15 @@
*/
drv_sw_scan_start(local);
- ieee80211_offchannel_stop_beaconing(local);
-
local->leave_oper_channel_time = 0;
local->next_scan_state = SCAN_DECISION;
local->scan_channel_idx = 0;
- drv_flush(local, false);
+ /* We always want to use off-channel PS, even if we
+ * are not really leaving oper-channel. Don't
+ * tell the AP though, as long as we are on-channel.
+ */
+ ieee80211_offchannel_enable_all_ps(local, false);
ieee80211_configure_filter(local);
@@ -487,7 +513,21 @@
}
mutex_unlock(&local->iflist_mtx);
- if (local->scan_channel) {
+ next_chan = local->scan_req->channels[local->scan_channel_idx];
+
+ if (ieee80211_cfg_on_oper_channel(local)) {
+ /* We're currently on operating channel. */
+ if ((next_chan == local->oper_channel) &&
+ (local->_oper_channel_type == NL80211_CHAN_NO_HT))
+ /* We don't need to move off of operating channel. */
+ local->next_scan_state = SCAN_SET_CHANNEL;
+ else
+ /*
+ * We do need to leave operating channel, as next
+ * scan is somewhere else.
+ */
+ local->next_scan_state = SCAN_LEAVE_OPER_CHANNEL;
+ } else {
/*
* we're currently scanning a different channel, let's
* see if we can scan another channel without interfering
@@ -503,7 +543,6 @@
*
* Otherwise switch back to the operating channel.
*/
- next_chan = local->scan_req->channels[local->scan_channel_idx];
bad_latency = time_after(jiffies +
ieee80211_scan_get_channel_time(next_chan),
@@ -521,12 +560,6 @@
local->next_scan_state = SCAN_ENTER_OPER_CHANNEL;
else
local->next_scan_state = SCAN_SET_CHANNEL;
- } else {
- /*
- * we're on the operating channel currently, let's
- * leave that channel now to scan another one
- */
- local->next_scan_state = SCAN_LEAVE_OPER_CHANNEL;
}
*next_delay = 0;
@@ -535,9 +568,10 @@
static void ieee80211_scan_state_leave_oper_channel(struct ieee80211_local *local,
unsigned long *next_delay)
{
- ieee80211_offchannel_stop_station(local);
-
- __set_bit(SCAN_OFF_CHANNEL, &local->scanning);
+ /* PS will already be in off-channel mode,
+ * we do that once at the beginning of scanning.
+ */
+ ieee80211_offchannel_stop_vifs(local, false);
/*
* What if the nullfunc frames didn't arrive?
@@ -560,15 +594,15 @@
{
/* switch back to the operating channel */
local->scan_channel = NULL;
- ieee80211_hw_config(local, IEEE80211_CONF_CHANGE_CHANNEL);
+ if (!ieee80211_cfg_on_oper_channel(local))
+ ieee80211_hw_config(local, IEEE80211_CONF_CHANGE_CHANNEL);
/*
- * Only re-enable station mode interface now; beaconing will be
- * re-enabled once the full scan has been completed.
+ * Re-enable vifs and beaconing. Leave PS
+ * in off-channel state..will put that back
+ * on-channel at the end of scanning.
*/
- ieee80211_offchannel_return(local, false);
-
- __clear_bit(SCAN_OFF_CHANNEL, &local->scanning);
+ ieee80211_offchannel_return(local, true, false);
*next_delay = HZ / 5;
local->next_scan_state = SCAN_DECISION;
@@ -584,8 +618,12 @@
chan = local->scan_req->channels[local->scan_channel_idx];
local->scan_channel = chan;
- if (ieee80211_hw_config(local, IEEE80211_CONF_CHANGE_CHANNEL))
- skip = 1;
+
+ /* Only call hw-config if we really need to change channels. */
+ if ((chan != local->hw.conf.channel) ||
+ (local->hw.conf.channel_type != NL80211_CHAN_NO_HT))
+ if (ieee80211_hw_config(local, IEEE80211_CONF_CHANGE_CHANNEL))
+ skip = 1;
/* advance state machine to next channel/band */
local->scan_channel_idx++;