mac80211: implement SMPS for AP

When the driver requests to move to STATIC or DYNAMIC SMPS,
we send an action frame to each associated station and
reconfigure the channel context / driver.
Of course, non-MIMO stations are ignored.

The beacon isn't updated. The association response will
include the original capabilities. Stations that associate
while in non-OFF SMPS mode will get an action frame right
after association to inform them about our current state.
Note that we wait until the end of the EAPOL. Sending an
action frame before the EAPOL is finished can be an issue
for a few clients. Clients aren't likely to send EAPOL
frames in MIMO anyway.

When the SMPS configuration gets more permissive (e.g.
STATIC -> OFF), we don't wake up stations that are asleep
We remember that they don't know about the change and send
the action frame when they wake up.

When the SMPS configuration gets more restrictive (e.g.
OFF -> STATIC), we set the TIM bit for every sleeping STA.
uAPSD stations might send MIMO until they poll the action
frame, but this is for a short period of time.

Signed-off-by: Emmanuel Grumbach <emmanuel.grumbach@intel.com>
[fix vht streams loop, initialisation]
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

1 files changed, 31 insertions, 10 deletions

diff --git a/net/mac80211/ht.c b/net/mac80211/ht.c
index 529bf58..9a8be8f 100644
--- a/net/mac80211/ht.c
+++ b/net/mac80211/ht.c
@@ -448,14 +448,25 @@ int ieee80211_send_smps_action(struct ieee80211_sub_if_data *sdata,
 	return 0;
 }
 
-void ieee80211_request_smps_work(struct work_struct *work)
+void ieee80211_request_smps_mgd_work(struct work_struct *work)
 {
 	struct ieee80211_sub_if_data *sdata =
 		container_of(work, struct ieee80211_sub_if_data,
 			     u.mgd.request_smps_work);
 
 	sdata_lock(sdata);
-	__ieee80211_request_smps(sdata, sdata->u.mgd.driver_smps_mode);
+	__ieee80211_request_smps_mgd(sdata, sdata->u.mgd.driver_smps_mode);
+	sdata_unlock(sdata);
+}
+
+void ieee80211_request_smps_ap_work(struct work_struct *work)
+{
+	struct ieee80211_sub_if_data *sdata =
+		container_of(work, struct ieee80211_sub_if_data,
+			     u.ap.request_smps_work);
+
+	sdata_lock(sdata);
+	__ieee80211_request_smps_ap(sdata, sdata->u.ap.driver_smps_mode);
 	sdata_unlock(sdata);
 }
 
@@ -464,19 +475,29 @@ void ieee80211_request_smps(struct ieee80211_vif *vif,
 {
 	struct ieee80211_sub_if_data *sdata = vif_to_sdata(vif);
 
-	if (WARN_ON(vif->type != NL80211_IFTYPE_STATION))
+	if (WARN_ON_ONCE(vif->type != NL80211_IFTYPE_STATION &&
+			 vif->type != NL80211_IFTYPE_AP))
 		return;
 
 	if (WARN_ON(smps_mode == IEEE80211_SMPS_OFF))
 		smps_mode = IEEE80211_SMPS_AUTOMATIC;
 
-	if (sdata->u.mgd.driver_smps_mode == smps_mode)
-		return;
-
-	sdata->u.mgd.driver_smps_mode = smps_mode;
-
-	ieee80211_queue_work(&sdata->local->hw,
-			     &sdata->u.mgd.request_smps_work);
+	if (vif->type == NL80211_IFTYPE_STATION) {
+		if (sdata->u.mgd.driver_smps_mode == smps_mode)
+			return;
+		sdata->u.mgd.driver_smps_mode = smps_mode;
+		ieee80211_queue_work(&sdata->local->hw,
+				     &sdata->u.mgd.request_smps_work);
+	} else {
+		/* AUTOMATIC is meaningless in AP mode */
+		if (WARN_ON_ONCE(smps_mode == IEEE80211_SMPS_AUTOMATIC))
+			return;
+		if (sdata->u.ap.driver_smps_mode == smps_mode)
+			return;
+		sdata->u.ap.driver_smps_mode = smps_mode;
+		ieee80211_queue_work(&sdata->local->hw,
+				     &sdata->u.ap.request_smps_work);
+	}
 }
 /* this might change ... don't want non-open drivers using it */
 EXPORT_SYMBOL_GPL(ieee80211_request_smps);