mac80211: Fix dynamic power save for scanning.
Not only ps_sdata but also IEEE80211_CONF_PS is to be considered
before restoring PS in scan_ps_disable(). For instance, when ps_sdata
is set but CONF_PS is not set just because the dynamic timer is still
running, a sw scan leads to setting of CONF_PS in scan_ps_disable
instead of restarting the dynamic PS timer.
Also for the above case, a null data frame is to be sent after
returning to operating channel which was not happening with the
current implementation. This patch fixes this too.
Signed-off-by: Vivek Natarajan <vnatarajan@atheros.com>
Reviewed-by: Kalle Valo <kalle.valo@nokia.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
diff --git a/net/mac80211/scan.c b/net/mac80211/scan.c
index 4cf387c..f1a4c71 100644
--- a/net/mac80211/scan.c
+++ b/net/mac80211/scan.c
@@ -227,7 +227,8 @@
static void ieee80211_scan_ps_enable(struct ieee80211_sub_if_data *sdata)
{
struct ieee80211_local *local = sdata->local;
- bool ps = false;
+
+ local->scan_ps_enabled = false;
/* FIXME: what to do when local->pspolling is true? */
@@ -235,12 +236,13 @@
cancel_work_sync(&local->dynamic_ps_enable_work);
if (local->hw.conf.flags & IEEE80211_CONF_PS) {
- ps = true;
+ local->scan_ps_enabled = true;
local->hw.conf.flags &= ~IEEE80211_CONF_PS;
ieee80211_hw_config(local, IEEE80211_CONF_CHANGE_PS);
}
- if (!ps || !(local->hw.flags & IEEE80211_HW_PS_NULLFUNC_STACK))
+ if (!(local->scan_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
@@ -261,7 +263,7 @@
if (!local->ps_sdata)
ieee80211_send_nullfunc(local, sdata, 0);
- else {
+ else if (local->scan_ps_enabled) {
/*
* In !IEEE80211_HW_PS_NULLFUNC_STACK case the hardware
* will send a nullfunc frame with the powersave bit set
@@ -277,6 +279,16 @@
*/
local->hw.conf.flags |= IEEE80211_CONF_PS;
ieee80211_hw_config(local, IEEE80211_CONF_CHANGE_PS);
+ } else if (local->hw.conf.dynamic_ps_timeout > 0) {
+ /*
+ * If IEEE80211_CONF_PS was not set and the dynamic_ps_timer
+ * had been running before leaving the operating channel,
+ * restart the timer now and send a nullfunc frame to inform
+ * the AP that we are awake.
+ */
+ ieee80211_send_nullfunc(local, sdata, 0);
+ mod_timer(&local->dynamic_ps_timer, jiffies +
+ msecs_to_jiffies(local->hw.conf.dynamic_ps_timeout));
}
}