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/ieee80211_i.h b/net/mac80211/ieee80211_i.h
index f71ed31..44eea1a 100644
--- a/net/mac80211/ieee80211_i.h
+++ b/net/mac80211/ieee80211_i.h
@@ -655,8 +655,6 @@
* well be on the operating channel
* @SCAN_HW_SCANNING: The hardware is scanning for us, we have no way to
* determine if we are on the operating channel or not
- * @SCAN_OFF_CHANNEL: We're off our operating channel for scanning,
- * gets only set in conjunction with SCAN_SW_SCANNING
* @SCAN_COMPLETED: Set for our scan work function when the driver reported
* that the scan completed.
* @SCAN_ABORTED: Set for our scan work function when the driver reported
@@ -665,7 +663,6 @@
enum {
SCAN_SW_SCANNING,
SCAN_HW_SCANNING,
- SCAN_OFF_CHANNEL,
SCAN_COMPLETED,
SCAN_ABORTED,
};
@@ -1148,10 +1145,14 @@
struct ieee80211_bss *bss);
/* off-channel helpers */
-void ieee80211_offchannel_stop_beaconing(struct ieee80211_local *local);
-void ieee80211_offchannel_stop_station(struct ieee80211_local *local);
+bool ieee80211_cfg_on_oper_channel(struct ieee80211_local *local);
+void ieee80211_offchannel_enable_all_ps(struct ieee80211_local *local,
+ bool tell_ap);
+void ieee80211_offchannel_stop_vifs(struct ieee80211_local *local,
+ bool offchannel_ps_enable);
void ieee80211_offchannel_return(struct ieee80211_local *local,
- bool enable_beaconing);
+ bool enable_beaconing,
+ bool offchannel_ps_disable);
void ieee80211_hw_roc_setup(struct ieee80211_local *local);
/* interface handling */
diff --git a/net/mac80211/main.c b/net/mac80211/main.c
index 09a2744..c155c0b 100644
--- a/net/mac80211/main.c
+++ b/net/mac80211/main.c
@@ -98,6 +98,41 @@
ieee80211_configure_filter(local);
}
+/*
+ * Returns true if we are logically configured to be on
+ * the operating channel AND the hardware-conf is currently
+ * configured on the operating channel. Compares channel-type
+ * as well.
+ */
+bool ieee80211_cfg_on_oper_channel(struct ieee80211_local *local)
+{
+ struct ieee80211_channel *chan, *scan_chan;
+ enum nl80211_channel_type channel_type;
+
+ /* This logic needs to match logic in ieee80211_hw_config */
+ if (local->scan_channel) {
+ chan = local->scan_channel;
+ channel_type = NL80211_CHAN_NO_HT;
+ } else if (local->tmp_channel) {
+ chan = scan_chan = local->tmp_channel;
+ channel_type = local->tmp_channel_type;
+ } else {
+ chan = local->oper_channel;
+ channel_type = local->_oper_channel_type;
+ }
+
+ if (chan != local->oper_channel ||
+ channel_type != local->_oper_channel_type)
+ return false;
+
+ /* Check current hardware-config against oper_channel. */
+ if ((local->oper_channel != local->hw.conf.channel) ||
+ (local->_oper_channel_type != local->hw.conf.channel_type))
+ return false;
+
+ return true;
+}
+
int ieee80211_hw_config(struct ieee80211_local *local, u32 changed)
{
struct ieee80211_channel *chan, *scan_chan;
@@ -110,21 +145,27 @@
scan_chan = local->scan_channel;
+ /* If this off-channel logic ever changes, ieee80211_on_oper_channel
+ * may need to change as well.
+ */
offchannel_flag = local->hw.conf.flags & IEEE80211_CONF_OFFCHANNEL;
if (scan_chan) {
chan = scan_chan;
channel_type = NL80211_CHAN_NO_HT;
- local->hw.conf.flags |= IEEE80211_CONF_OFFCHANNEL;
- } else if (local->tmp_channel &&
- local->oper_channel != local->tmp_channel) {
+ } else if (local->tmp_channel) {
chan = scan_chan = local->tmp_channel;
channel_type = local->tmp_channel_type;
- local->hw.conf.flags |= IEEE80211_CONF_OFFCHANNEL;
} else {
chan = local->oper_channel;
channel_type = local->_oper_channel_type;
- local->hw.conf.flags &= ~IEEE80211_CONF_OFFCHANNEL;
}
+
+ if (chan != local->oper_channel ||
+ channel_type != local->_oper_channel_type)
+ local->hw.conf.flags |= IEEE80211_CONF_OFFCHANNEL;
+ else
+ local->hw.conf.flags &= ~IEEE80211_CONF_OFFCHANNEL;
+
offchannel_flag ^= local->hw.conf.flags & IEEE80211_CONF_OFFCHANNEL;
if (offchannel_flag || chan != local->hw.conf.channel ||
@@ -231,7 +272,7 @@
if (changed & BSS_CHANGED_BEACON_ENABLED) {
if (local->quiescing || !ieee80211_sdata_running(sdata) ||
- test_bit(SCAN_SW_SCANNING, &local->scanning)) {
+ test_bit(SDATA_STATE_OFFCHANNEL, &sdata->state)) {
sdata->vif.bss_conf.enable_beacon = false;
} else {
/*
diff --git a/net/mac80211/offchannel.c b/net/mac80211/offchannel.c
index b4e5267..13427b1 100644
--- a/net/mac80211/offchannel.c
+++ b/net/mac80211/offchannel.c
@@ -17,10 +17,14 @@
#include "driver-trace.h"
/*
- * inform AP that we will go to sleep so that it will buffer the frames
- * while we scan
+ * Tell our hardware to disable PS.
+ * Optionally inform AP that we will go to sleep so that it will buffer
+ * the frames while we are doing off-channel work. This is optional
+ * because we *may* be doing work on-operating channel, and want our
+ * hardware unconditionally awake, but still let the AP send us normal frames.
*/
-static void ieee80211_offchannel_ps_enable(struct ieee80211_sub_if_data *sdata)
+static void ieee80211_offchannel_ps_enable(struct ieee80211_sub_if_data *sdata,
+ bool tell_ap)
{
struct ieee80211_local *local = sdata->local;
struct ieee80211_if_managed *ifmgd = &sdata->u.mgd;
@@ -41,8 +45,8 @@
ieee80211_hw_config(local, IEEE80211_CONF_CHANGE_PS);
}
- if (!(local->offchannel_ps_enabled) ||
- !(local->hw.flags & IEEE80211_HW_PS_NULLFUNC_STACK))
+ if (tell_ap && (!local->offchannel_ps_enabled ||
+ !(local->hw.flags & IEEE80211_HW_PS_NULLFUNC_STACK)))
/*
* If power save was enabled, no need to send a nullfunc
* frame because AP knows that we are sleeping. But if the
@@ -77,6 +81,9 @@
* we are sleeping, let's just enable power save mode in
* hardware.
*/
+ /* TODO: Only set hardware if CONF_PS changed?
+ * TODO: Should we set offchannel_ps_enabled to false?
+ */
local->hw.conf.flags |= IEEE80211_CONF_PS;
ieee80211_hw_config(local, IEEE80211_CONF_CHANGE_PS);
} else if (local->hw.conf.dynamic_ps_timeout > 0) {
@@ -95,63 +102,61 @@
ieee80211_sta_reset_conn_monitor(sdata);
}
-void ieee80211_offchannel_stop_beaconing(struct ieee80211_local *local)
-{
- struct ieee80211_sub_if_data *sdata;
-
- mutex_lock(&local->iflist_mtx);
- list_for_each_entry(sdata, &local->interfaces, list) {
- if (!ieee80211_sdata_running(sdata))
- continue;
-
- /* disable beaconing */
- if (sdata->vif.type == NL80211_IFTYPE_AP ||
- sdata->vif.type == NL80211_IFTYPE_ADHOC ||
- sdata->vif.type == NL80211_IFTYPE_MESH_POINT)
- ieee80211_bss_info_change_notify(
- sdata, BSS_CHANGED_BEACON_ENABLED);
-
- /*
- * only handle non-STA interfaces here, STA interfaces
- * are handled in ieee80211_offchannel_stop_station(),
- * e.g., from the background scan state machine.
- *
- * In addition, do not stop monitor interface to allow it to be
- * used from user space controlled off-channel operations.
- */
- if (sdata->vif.type != NL80211_IFTYPE_STATION &&
- sdata->vif.type != NL80211_IFTYPE_MONITOR) {
- set_bit(SDATA_STATE_OFFCHANNEL, &sdata->state);
- netif_tx_stop_all_queues(sdata->dev);
- }
- }
- mutex_unlock(&local->iflist_mtx);
-}
-
-void ieee80211_offchannel_stop_station(struct ieee80211_local *local)
+void ieee80211_offchannel_stop_vifs(struct ieee80211_local *local,
+ bool offchannel_ps_enable)
{
struct ieee80211_sub_if_data *sdata;
/*
- * notify the AP about us leaving the channel and stop all STA interfaces
+ * notify the AP about us leaving the channel and stop all
+ * STA interfaces.
*/
mutex_lock(&local->iflist_mtx);
list_for_each_entry(sdata, &local->interfaces, list) {
if (!ieee80211_sdata_running(sdata))
continue;
- if (sdata->vif.type == NL80211_IFTYPE_STATION) {
+ if (sdata->vif.type != NL80211_IFTYPE_MONITOR)
set_bit(SDATA_STATE_OFFCHANNEL, &sdata->state);
+
+ /* Check to see if we should disable beaconing. */
+ if (sdata->vif.type == NL80211_IFTYPE_AP ||
+ sdata->vif.type == NL80211_IFTYPE_ADHOC ||
+ sdata->vif.type == NL80211_IFTYPE_MESH_POINT)
+ ieee80211_bss_info_change_notify(
+ sdata, BSS_CHANGED_BEACON_ENABLED);
+
+ if (sdata->vif.type != NL80211_IFTYPE_MONITOR) {
netif_tx_stop_all_queues(sdata->dev);
- if (sdata->u.mgd.associated)
- ieee80211_offchannel_ps_enable(sdata);
+ if (offchannel_ps_enable &&
+ (sdata->vif.type == NL80211_IFTYPE_STATION) &&
+ sdata->u.mgd.associated)
+ ieee80211_offchannel_ps_enable(sdata, true);
}
}
mutex_unlock(&local->iflist_mtx);
}
+void ieee80211_offchannel_enable_all_ps(struct ieee80211_local *local,
+ bool tell_ap)
+{
+ struct ieee80211_sub_if_data *sdata;
+
+ mutex_lock(&local->iflist_mtx);
+ list_for_each_entry(sdata, &local->interfaces, list) {
+ if (!ieee80211_sdata_running(sdata))
+ continue;
+
+ if (sdata->vif.type == NL80211_IFTYPE_STATION &&
+ sdata->u.mgd.associated)
+ ieee80211_offchannel_ps_enable(sdata, tell_ap);
+ }
+ mutex_unlock(&local->iflist_mtx);
+}
+
void ieee80211_offchannel_return(struct ieee80211_local *local,
- bool enable_beaconing)
+ bool enable_beaconing,
+ bool offchannel_ps_disable)
{
struct ieee80211_sub_if_data *sdata;
@@ -161,7 +166,8 @@
continue;
/* Tell AP we're back */
- if (sdata->vif.type == NL80211_IFTYPE_STATION) {
+ if (offchannel_ps_disable &&
+ sdata->vif.type == NL80211_IFTYPE_STATION) {
if (sdata->u.mgd.associated)
ieee80211_offchannel_ps_disable(sdata);
}
@@ -181,7 +187,7 @@
netif_tx_wake_all_queues(sdata->dev);
}
- /* re-enable beaconing */
+ /* Check to see if we should re-enable beaconing */
if (enable_beaconing &&
(sdata->vif.type == NL80211_IFTYPE_AP ||
sdata->vif.type == NL80211_IFTYPE_ADHOC ||
diff --git a/net/mac80211/rx.c b/net/mac80211/rx.c
index 753ffc4..b5f59ed 100644
--- a/net/mac80211/rx.c
+++ b/net/mac80211/rx.c
@@ -409,16 +409,10 @@
if (likely(!(status->rx_flags & IEEE80211_RX_IN_SCAN)))
return RX_CONTINUE;
- if (test_bit(SCAN_HW_SCANNING, &local->scanning))
+ if (test_bit(SCAN_HW_SCANNING, &local->scanning) ||
+ test_bit(SCAN_SW_SCANNING, &local->scanning))
return ieee80211_scan_rx(rx->sdata, skb);
- if (test_bit(SCAN_SW_SCANNING, &local->scanning)) {
- /* drop all the other packets during a software scan anyway */
- if (ieee80211_scan_rx(rx->sdata, skb) != RX_QUEUED)
- dev_kfree_skb(skb);
- return RX_QUEUED;
- }
-
/* scanning finished during invoking of handlers */
I802_DEBUG_INC(local->rx_handlers_drop_passive_scan);
return RX_DROP_UNUSABLE;
@@ -2793,7 +2787,7 @@
local->dot11ReceivedFragmentCount++;
if (unlikely(test_bit(SCAN_HW_SCANNING, &local->scanning) ||
- test_bit(SCAN_OFF_CHANNEL, &local->scanning)))
+ test_bit(SCAN_SW_SCANNING, &local->scanning)))
status->rx_flags |= IEEE80211_RX_IN_SCAN;
if (ieee80211_is_mgmt(fc))
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++;
diff --git a/net/mac80211/tx.c b/net/mac80211/tx.c
index bf67a223..2915168 100644
--- a/net/mac80211/tx.c
+++ b/net/mac80211/tx.c
@@ -257,7 +257,8 @@
if (unlikely(info->flags & IEEE80211_TX_CTL_INJECTED))
return TX_CONTINUE;
- if (unlikely(test_bit(SCAN_OFF_CHANNEL, &tx->local->scanning)) &&
+ if (unlikely(test_bit(SCAN_SW_SCANNING, &tx->local->scanning)) &&
+ test_bit(SDATA_STATE_OFFCHANNEL, &tx->sdata->state) &&
!ieee80211_is_probe_req(hdr->frame_control) &&
!ieee80211_is_nullfunc(hdr->frame_control))
/*
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);
}