mac80211: enable spatial multiplexing powersave

Enable spatial multiplexing in mac80211 by telling the
driver what to do and, where necessary, sending action
frames to the AP to update the requested SMPS mode.

Also includes a trivial implementation for hwsim that
just logs the requested mode.

For now, the userspace interface is in debugfs only,
and let you toggle the requested mode at any time.

Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

1 files changed, 38 insertions, 0 deletions

diff --git a/net/mac80211/status.c b/net/mac80211/status.c
index b4608f11a40f..0c0850d37dda 100644
--- a/net/mac80211/status.c
+++ b/net/mac80211/status.c
@@ -134,6 +134,40 @@ static void ieee80211_handle_filtered_frame(struct ieee80211_local *local,
         dev_kfree_skb(skb);
 }
 
+static void ieee80211_frame_acked(struct sta_info *sta, struct sk_buff *skb)
+{
+        struct ieee80211_mgmt *mgmt = (void *) skb->data;
+        struct ieee80211_local *local = sta->local;
+        struct ieee80211_sub_if_data *sdata = sta->sdata;
+
+        if (ieee80211_is_action(mgmt->frame_control) &&
+            sdata->vif.type == NL80211_IFTYPE_STATION &&
+            mgmt->u.action.category == WLAN_CATEGORY_HT &&
+            mgmt->u.action.u.ht_smps.action == WLAN_HT_ACTION_SMPS) {
+                /*
+                 * 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 is before we're associated.
+                 */
+                switch (mgmt->u.action.u.ht_smps.smps_control) {
+                case WLAN_HT_SMPS_CONTROL_DYNAMIC:
+                        sta->sdata->u.mgd.ap_smps = IEEE80211_SMPS_DYNAMIC;
+                        break;
+                case WLAN_HT_SMPS_CONTROL_STATIC:
+                        sta->sdata->u.mgd.ap_smps = IEEE80211_SMPS_STATIC;
+                        break;
+                case WLAN_HT_SMPS_CONTROL_DISABLED:
+                default: /* shouldn't happen since we don't send that */
+                        sta->sdata->u.mgd.ap_smps = IEEE80211_SMPS_OFF;
+                        break;
+                }
+
+                ieee80211_queue_work(&local->hw, &local->recalc_smps);
+        }
+}
+
 void ieee80211_tx_status(struct ieee80211_hw *hw, struct sk_buff *skb)
 {
         struct sk_buff *skb2;
@@ -210,6 +244,10 @@ void ieee80211_tx_status(struct ieee80211_hw *hw, struct sk_buff *skb)
                 rate_control_tx_status(local, sband, sta, skb);
                 if (ieee80211_vif_is_mesh(&sta->sdata->vif))
                         ieee80211s_update_metric(local, sta, skb);
+
+                if (!(info->flags & IEEE80211_TX_CTL_INJECTED) &&
+                    (info->flags & IEEE80211_TX_STAT_ACK))
+                        ieee80211_frame_acked(sta, skb);
         }
 
         rcu_read_unlock();