Commit 7c3f4bbe authored by Vivek Natarajan's avatar Vivek Natarajan Committed by John W. Linville
Browse files

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: default avatarVivek Natarajan <vnatarajan@atheros.com>
Reviewed-by: default avatarKalle Valo <kalle.valo@nokia.com>
Signed-off-by: default avatarJohn W. Linville <linville@tuxdriver.com>
parent bc83b681

net/mac80211/ieee80211_i.h

+1 −0
Original line number Diff line number Diff line
@@ -746,6 +746,7 @@ struct ieee80211_local { 
	unsigned int wmm_acm; /* bit field of ACM bits (BIT(802.1D tag)) */



	bool pspolling;

	bool scan_ps_enabled;

	/*

	 * PS can only be enabled when we have exactly one managed

	 * interface (and monitors) in PS, this then points there.

net/mac80211/scan.c

+16 −4
Original line number Diff line number Diff line
@@ -227,7 +227,8 @@ static bool ieee80211_prep_hw_scan(struct ieee80211_local *local) 
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 @@ static void ieee80211_scan_ps_enable(struct ieee80211_sub_if_data *sdata) 
	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 @@ static void ieee80211_scan_ps_disable(struct ieee80211_sub_if_data *sdata) 


	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 @@ static void ieee80211_scan_ps_disable(struct ieee80211_sub_if_data *sdata) 
		 */

		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));

	}

}

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