4 files changed, 42 insertions, 2 deletions

diff --git a/net/mac80211/ieee80211_i.h b/net/mac80211/ieee80211_i.h
index 9112c5247c35..c9ffadb55d36 100644
--- a/net/mac80211/ieee80211_i.h
+++ b/net/mac80211/ieee80211_i.h
@@ -715,6 +715,7 @@ struct ieee80211_local {
         struct timer_list dynamic_ps_timer;
 
         int user_power_level; /* in dBm */
+        int power_constr_level; /* in dBm */
 
 #ifdef CONFIG_MAC80211_DEBUGFS
         struct local_debugfsdentries {
@@ -985,6 +986,9 @@ void ieee80211_chswitch_work(struct work_struct *work);
 void ieee80211_process_chanswitch(struct ieee80211_sub_if_data *sdata,
                                   struct ieee80211_channel_sw_ie *sw_elem,
                                   struct ieee80211_bss *bss);
+void ieee80211_handle_pwr_constr(struct ieee80211_sub_if_data *sdata,
+                                 u16 capab_info, u8 *pwr_constr_elem,
+                                 u8 pwr_constr_elem_len);
 
 /* utility functions/constants */
 extern void *mac80211_wiphy_privid; /* for wiphy privid */
diff --git a/net/mac80211/main.c b/net/mac80211/main.c
index e9f3e85d1a9e..c78304db475e 100644
--- a/net/mac80211/main.c
+++ b/net/mac80211/main.c
@@ -214,10 +214,16 @@ int ieee80211_hw_config(struct ieee80211_local *local, u32 changed)
                 changed |= IEEE80211_CONF_CHANGE_CHANNEL;
         }
 
-        if (!local->user_power_level)
+        if (local->sw_scanning)
                 power = chan->max_power;
         else
-                power = min(chan->max_power, local->user_power_level);
+                power = local->power_constr_level ?
+                        (chan->max_power - local->power_constr_level) :
+                        chan->max_power;
+
+        if (local->user_power_level)
+                power = min(power, local->user_power_level);
+
         if (local->hw.conf.power_level != power) {
                 changed |= IEEE80211_CONF_CHANGE_POWER;
                 local->hw.conf.power_level = power;
diff --git a/net/mac80211/mlme.c b/net/mac80211/mlme.c
index 82c598a83687..f0d42498c257 100644
--- a/net/mac80211/mlme.c
+++ b/net/mac80211/mlme.c
@@ -905,6 +905,8 @@ static void ieee80211_set_disassoc(struct ieee80211_sub_if_data *sdata,
         /* channel(_type) changes are handled by ieee80211_hw_config */
         local->oper_channel_type = NL80211_CHAN_NO_HT;
 
+        local->power_constr_level = 0;
+
         del_timer_sync(&local->dynamic_ps_timer);
         cancel_work_sync(&local->dynamic_ps_enable_work);
 
@@ -1849,6 +1851,13 @@ static void ieee80211_rx_mgmt_beacon(struct ieee80211_sub_if_data *sdata,
                  * for the BSSID we are associated to */
                 regulatory_hint_11d(local->hw.wiphy,
                         elems.country_elem, elems.country_elem_len);
+
+                /* TODO: IBSS also needs this */
+                if (elems.pwr_constr_elem)
+                        ieee80211_handle_pwr_constr(sdata,
+                                le16_to_cpu(mgmt->u.probe_resp.capab_info),
+                                elems.pwr_constr_elem,
+                                elems.pwr_constr_elem_len);
         }
 
         ieee80211_bss_info_change_notify(sdata, changed);
diff --git a/net/mac80211/spectmgmt.c b/net/mac80211/spectmgmt.c
index 8396b5a77e8d..8d4ec2968f8f 100644
--- a/net/mac80211/spectmgmt.c
+++ b/net/mac80211/spectmgmt.c
@@ -161,3 +161,24 @@ void ieee80211_process_chanswitch(struct ieee80211_sub_if_data *sdata,
                           jiffies + msecs_to_jiffies(sw_elem->count * bss->beacon_int));
         }
 }
+
+void ieee80211_handle_pwr_constr(struct ieee80211_sub_if_data *sdata,
+                                 u16 capab_info, u8 *pwr_constr_elem,
+                                 u8 pwr_constr_elem_len)
+{
+        struct ieee80211_conf *conf = &sdata->local->hw.conf;
+
+        if (!(capab_info & WLAN_CAPABILITY_SPECTRUM_MGMT))
+                return;
+
+        /* Power constraint IE length should be 1 octet */
+        if (pwr_constr_elem_len != 1)
+                return;
+
+        if ((*pwr_constr_elem <= conf->channel->max_power) &&
+            (*pwr_constr_elem != sdata->local->power_constr_level)) {
+                sdata->local->power_constr_level = *pwr_constr_elem;
+                ieee80211_hw_config(sdata->local, 0);
+        }
+}
+