[PATCH 42/93] mac80211: synchronize scan off/on-channel and PS states

From: Herton Ronaldo Krzesinski
Date: Tue Feb 05 2013 - 17:10:29 EST


3.5.7.5 -stable review patch. If anyone has any objections, please let me know.

------------------

From: Stanislaw Gruszka <sgruszka@xxxxxxxxxx>

commit aacde9ee45225f7e0b90960f479aef83c66bfdc0 upstream.

Since:

commit b23b025fe246f3acc2988eb6d400df34c27cb8ae
Author: Ben Greear <greearb@xxxxxxxxxxxxxxx>
Date: Fri Feb 4 11:54:17 2011 -0800

mac80211: Optimize scans on current operating channel.

we do not disable PS while going back to operational channel (on
ieee80211_scan_state_suspend) and deffer that until scan finish.
But since we are allowed to send frames, we can send a frame to AP
without PM bit set, so disable PS on AP side. Then when we switch
to off-channel (in ieee80211_scan_state_resume) we do not enable PS.
Hence we are off-channel with PS disabled, frames are not buffered
by AP.

To fix remove offchannel_ps_disable argument and always enable PS when
going off-channel and disable it when going on-channel, like it was
before.

Signed-off-by: Stanislaw Gruszka <sgruszka@xxxxxxxxxx>
Tested-by: Seth Forshee <seth.forshee@xxxxxxxxxxxxx>
Signed-off-by: Johannes Berg <johannes.berg@xxxxxxxxx>
[ herton: adjust context, and patch extra ieee80211_offchannel_return/
ieee80211_offchannel_stop_vifs calls in ieee80211_work_work (also
drop change to ieee80211_sw_roc_work, which didn't exist yet) ]
Signed-off-by: Herton Ronaldo Krzesinski <herton.krzesinski@xxxxxxxxxxxxx>
---
net/mac80211/ieee80211_i.h | 6 ++----
net/mac80211/offchannel.c | 17 ++++++-----------
net/mac80211/scan.c | 15 +++++----------
net/mac80211/work.c | 4 ++--
4 files changed, 15 insertions(+), 27 deletions(-)

diff --git a/net/mac80211/ieee80211_i.h b/net/mac80211/ieee80211_i.h
index 16655d6..1d025ca 100644
--- a/net/mac80211/ieee80211_i.h
+++ b/net/mac80211/ieee80211_i.h
@@ -1283,10 +1283,8 @@ int ieee80211_request_sched_scan_stop(struct ieee80211_sub_if_data *sdata);
void ieee80211_sched_scan_stopped_work(struct work_struct *work);

/* off-channel helpers */
-void ieee80211_offchannel_stop_vifs(struct ieee80211_local *local,
- bool offchannel_ps_enable);
-void ieee80211_offchannel_return(struct ieee80211_local *local,
- bool offchannel_ps_disable);
+void ieee80211_offchannel_stop_vifs(struct ieee80211_local *local);
+void ieee80211_offchannel_return(struct ieee80211_local *local);
void ieee80211_hw_roc_setup(struct ieee80211_local *local);

/* interface handling */
diff --git a/net/mac80211/offchannel.c b/net/mac80211/offchannel.c
index 935aa4b..c22f074 100644
--- a/net/mac80211/offchannel.c
+++ b/net/mac80211/offchannel.c
@@ -103,8 +103,7 @@ static void ieee80211_offchannel_ps_disable(struct ieee80211_sub_if_data *sdata)
ieee80211_sta_reset_conn_monitor(sdata);
}

-void ieee80211_offchannel_stop_vifs(struct ieee80211_local *local,
- bool offchannel_ps_enable)
+void ieee80211_offchannel_stop_vifs(struct ieee80211_local *local)
{
struct ieee80211_sub_if_data *sdata;

@@ -129,8 +128,7 @@ void ieee80211_offchannel_stop_vifs(struct ieee80211_local *local,

if (sdata->vif.type != NL80211_IFTYPE_MONITOR) {
netif_tx_stop_all_queues(sdata->dev);
- if (offchannel_ps_enable &&
- (sdata->vif.type == NL80211_IFTYPE_STATION) &&
+ if (sdata->vif.type == NL80211_IFTYPE_STATION &&
sdata->u.mgd.associated)
ieee80211_offchannel_ps_enable(sdata, true);
}
@@ -138,8 +136,7 @@ void ieee80211_offchannel_stop_vifs(struct ieee80211_local *local,
mutex_unlock(&local->iflist_mtx);
}

-void ieee80211_offchannel_return(struct ieee80211_local *local,
- bool offchannel_ps_disable)
+void ieee80211_offchannel_return(struct ieee80211_local *local)
{
struct ieee80211_sub_if_data *sdata;

@@ -152,11 +149,9 @@ void ieee80211_offchannel_return(struct ieee80211_local *local,
continue;

/* Tell AP we're back */
- if (offchannel_ps_disable &&
- sdata->vif.type == NL80211_IFTYPE_STATION) {
- if (sdata->u.mgd.associated)
- ieee80211_offchannel_ps_disable(sdata);
- }
+ if (sdata->vif.type == NL80211_IFTYPE_STATION &&
+ sdata->u.mgd.associated)
+ ieee80211_offchannel_ps_disable(sdata);

if (sdata->vif.type != NL80211_IFTYPE_MONITOR) {
/*
diff --git a/net/mac80211/scan.c b/net/mac80211/scan.c
index 58ac7d0..bb456ac 100644
--- a/net/mac80211/scan.c
+++ b/net/mac80211/scan.c
@@ -302,7 +302,7 @@ static void __ieee80211_scan_completed(struct ieee80211_hw *hw, bool aborted,
if (!was_hw_scan) {
ieee80211_configure_filter(local);
drv_sw_scan_complete(local);
- ieee80211_offchannel_return(local, true);
+ ieee80211_offchannel_return(local);
}

ieee80211_recalc_idle(local);
@@ -347,7 +347,7 @@ static int ieee80211_start_sw_scan(struct ieee80211_local *local)
local->next_scan_state = SCAN_DECISION;
local->scan_channel_idx = 0;

- ieee80211_offchannel_stop_vifs(local, true);
+ ieee80211_offchannel_stop_vifs(local);

ieee80211_configure_filter(local);

@@ -666,12 +666,8 @@ static void ieee80211_scan_state_suspend(struct ieee80211_local *local,
local->scan_channel = NULL;
ieee80211_hw_config(local, IEEE80211_CONF_CHANGE_CHANNEL);

- /*
- * 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);
+ /* disable PS */
+ ieee80211_offchannel_return(local);

*next_delay = HZ / 5;
/* afterwards, resume scan & go to next channel */
@@ -681,8 +677,7 @@ static void ieee80211_scan_state_suspend(struct ieee80211_local *local,
static void ieee80211_scan_state_resume(struct ieee80211_local *local,
unsigned long *next_delay)
{
- /* PS already is in off-channel mode */
- ieee80211_offchannel_stop_vifs(local, false);
+ ieee80211_offchannel_stop_vifs(local);

if (local->ops->flush) {
drv_flush(local, false);
diff --git a/net/mac80211/work.c b/net/mac80211/work.c
index b2650a9..67c739c 100644
--- a/net/mac80211/work.c
+++ b/net/mac80211/work.c
@@ -150,7 +150,7 @@ static void ieee80211_work_work(struct work_struct *work)
}

if (!started && !local->tmp_channel) {
- ieee80211_offchannel_stop_vifs(local, true);
+ ieee80211_offchannel_stop_vifs(local);

local->tmp_channel = wk->chan;
local->tmp_channel_type = wk->chan_type;
@@ -222,7 +222,7 @@ static void ieee80211_work_work(struct work_struct *work)
local->tmp_channel = NULL;
ieee80211_hw_config(local, 0);

- ieee80211_offchannel_return(local, true);
+ ieee80211_offchannel_return(local);

/* give connection some time to breathe */
run_again(local, jiffies + HZ/2);
--
1.7.9.5

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