1 files changed, 74 insertions, 0 deletions

diff --git a/net/mac80211/util.c b/net/mac80211/util.c
index d54dbe8e09ba..086ef6257b4b 100644
--- a/net/mac80211/util.c
+++ b/net/mac80211/util.c
@@ -1170,3 +1170,77 @@ int ieee80211_reconfig(struct ieee80211_local *local)
         return 0;
 }
 
+static int check_mgd_smps(struct ieee80211_if_managed *ifmgd,
+                          enum ieee80211_smps_mode *smps_mode)
+{
+        if (ifmgd->associated) {
+                *smps_mode = ifmgd->ap_smps;
+
+                if (*smps_mode == IEEE80211_SMPS_AUTOMATIC) {
+                        if (ifmgd->powersave)
+                                *smps_mode = IEEE80211_SMPS_DYNAMIC;
+                        else
+                                *smps_mode = IEEE80211_SMPS_OFF;
+                }
+
+                return 1;
+        }
+
+        return 0;
+}
+
+/* must hold iflist_mtx */
+void ieee80211_recalc_smps(struct ieee80211_local *local,
+                           struct ieee80211_sub_if_data *forsdata)
+{
+        struct ieee80211_sub_if_data *sdata;
+        enum ieee80211_smps_mode smps_mode = IEEE80211_SMPS_OFF;
+        int count = 0;
+
+        if (forsdata)
+                WARN_ON(!mutex_is_locked(&forsdata->u.mgd.mtx));
+
+        WARN_ON(!mutex_is_locked(&local->iflist_mtx));
+
+        /*
+         * This function could be improved to handle multiple
+         * interfaces better, but right now it makes any
+         * non-station interfaces force SM PS to be turned
+         * off. If there are multiple station interfaces it
+         * could also use the best possible mode, e.g. if
+         * one is in static and the other in dynamic then
+         * dynamic is ok.
+         */
+
+        list_for_each_entry(sdata, &local->interfaces, list) {
+                if (!netif_running(sdata->dev))
+                        continue;
+                if (sdata->vif.type != NL80211_IFTYPE_STATION)
+                        goto set;
+                if (sdata != forsdata) {
+                        /*
+                         * This nested is ok -- we are holding the iflist_mtx
+                         * so can't get here twice or so. But it's required
+                         * since normally we acquire it first and then the
+                         * iflist_mtx.
+                         */
+                        mutex_lock_nested(&sdata->u.mgd.mtx, SINGLE_DEPTH_NESTING);
+                        count += check_mgd_smps(&sdata->u.mgd, &smps_mode);
+                        mutex_unlock(&sdata->u.mgd.mtx);
+                } else
+                        count += check_mgd_smps(&sdata->u.mgd, &smps_mode);
+
+                if (count > 1) {
+                        smps_mode = IEEE80211_SMPS_OFF;
+                        break;
+                }
+        }
+
+        if (smps_mode == local->smps_mode)
+                return;
+
+ set:
+        local->smps_mode = smps_mode;
+        /* changed flag is auto-detected for this */
+        ieee80211_hw_config(local, 0);
+}