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, 19 insertions, 12 deletions

diff --git a/net/mac80211/status.c b/net/mac80211/status.c
index 368837fe3b80..1ced74c73d2f 100644
--- a/net/mac80211/status.c
+++ b/net/mac80211/status.c
@@ -191,29 +191,36 @@ static void ieee80211_frame_acked(struct sta_info *sta, struct sk_buff *skb)
         if (ieee80211_is_action(mgmt->frame_control) &&
             mgmt->u.action.category == WLAN_CATEGORY_HT &&
             mgmt->u.action.u.ht_smps.action == WLAN_HT_ACTION_SMPS &&
-            sdata->vif.type == NL80211_IFTYPE_STATION &&
             ieee80211_sdata_running(sdata)) {
-                /*
-                 * This update looks racy, but isn't -- if we come
-                 * here we've definitely got a station that we're
-                 * talking to, and on a managed interface that can
-                 * only be the AP. And the only other place updating
-                 * this variable in managed mode is before association.
-                 */
+                enum ieee80211_smps_mode smps_mode;
+
                 switch (mgmt->u.action.u.ht_smps.smps_control) {
                 case WLAN_HT_SMPS_CONTROL_DYNAMIC:
-                        sdata->smps_mode = IEEE80211_SMPS_DYNAMIC;
+                        smps_mode = IEEE80211_SMPS_DYNAMIC;
                         break;
                 case WLAN_HT_SMPS_CONTROL_STATIC:
-                        sdata->smps_mode = IEEE80211_SMPS_STATIC;
+                        smps_mode = IEEE80211_SMPS_STATIC;
                         break;
                 case WLAN_HT_SMPS_CONTROL_DISABLED:
                 default: /* shouldn't happen since we don't send that */
-                        sdata->smps_mode = IEEE80211_SMPS_OFF;
+                        smps_mode = IEEE80211_SMPS_OFF;
                         break;
                 }
 
-                ieee80211_queue_work(&local->hw, &sdata->recalc_smps);
+                if (sdata->vif.type == NL80211_IFTYPE_STATION) {
+                        /*
+                         * This update looks racy, but isn't -- if we come
+                         * here we've definitely got a station that we're
+                         * talking to, and on a managed interface that can
+                         * only be the AP. And the only other place updating
+                         * this variable in managed mode is before association.
+                         */
+                        sdata->smps_mode = smps_mode;
+                        ieee80211_queue_work(&local->hw, &sdata->recalc_smps);
+                } else if (sdata->vif.type == NL80211_IFTYPE_AP ||
+                           sdata->vif.type == NL80211_IFTYPE_AP_VLAN) {
+                        sta->known_smps_mode = smps_mode;
+                }
         }
 }