mac80211: handle TX power per virtual interface

Even before channel contexts/multi-channel, having a
single global TX power limit was already problematic,
in particular if two managed interfaces connected to
two APs with different power constraints. The channel
context introduction completely broke this though and
in fact I had disabled TX power configuration there
for drivers using channel contexts.

Change everything to track TX power per interface so
that different user settings and different channel
maxima are treated correctly. Also continue tracking
the global TX power though for compatibility with
applications that attempt to configure the wiphy's
TX power globally.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>

1 files changed, 16 insertions, 11 deletions

diff --git a/net/mac80211/main.c b/net/mac80211/main.c
index fd8345c20051..70e87600cacc 100644
--- a/net/mac80211/main.c
+++ b/net/mac80211/main.c
@@ -95,11 +95,13 @@ static void ieee80211_reconfig_filter(struct work_struct *work)
 
 static u32 ieee80211_hw_conf_chan(struct ieee80211_local *local)
 {
+        struct ieee80211_sub_if_data *sdata;
         struct ieee80211_channel *chan;
         u32 changed = 0;
         int power;
         enum nl80211_channel_type channel_type;
         u32 offchannel_flag;
+        bool scanning = false;
 
         offchannel_flag = local->hw.conf.flags & IEEE80211_CONF_OFFCHANNEL;
         if (local->scan_channel) {
@@ -146,16 +148,18 @@ static u32 ieee80211_hw_conf_chan(struct ieee80211_local *local)
                 changed |= IEEE80211_CONF_CHANGE_SMPS;
         }
 
-        if (test_bit(SCAN_SW_SCANNING, &local->scanning) ||
-            test_bit(SCAN_ONCHANNEL_SCANNING, &local->scanning) ||
-            test_bit(SCAN_HW_SCANNING, &local->scanning) ||
-            !local->ap_power_level)
-                power = chan->max_power;
-        else
-                power = min(chan->max_power, local->ap_power_level);
+        scanning = test_bit(SCAN_SW_SCANNING, &local->scanning) ||
+                   test_bit(SCAN_ONCHANNEL_SCANNING, &local->scanning) ||
+                   test_bit(SCAN_HW_SCANNING, &local->scanning);
+        power = chan->max_power;
 
-        if (local->user_power_level >= 0)
-                power = min(power, local->user_power_level);
+        rcu_read_lock();
+        list_for_each_entry_rcu(sdata, &local->interfaces, list) {
+                if (!rcu_access_pointer(sdata->vif.chanctx_conf))
+                        continue;
+                power = min(power, sdata->vif.bss_conf.txpower);
+        }
+        rcu_read_unlock();
 
         if (local->hw.conf.power_level != power) {
                 changed |= IEEE80211_CONF_CHANGE_POWER;
@@ -600,7 +604,8 @@ struct ieee80211_hw *ieee80211_alloc_hw(size_t priv_data_len,
 
         wiphy->features |= NL80211_FEATURE_SK_TX_STATUS |
                            NL80211_FEATURE_SAE |
-                           NL80211_FEATURE_HT_IBSS;
+                           NL80211_FEATURE_HT_IBSS |
+                           NL80211_FEATURE_VIF_TXPOWER;
 
         if (!ops->hw_scan)
                 wiphy->features |= NL80211_FEATURE_LOW_PRIORITY_SCAN |
@@ -633,7 +638,7 @@ struct ieee80211_hw *ieee80211_alloc_hw(size_t priv_data_len,
         local->hw.radiotap_mcs_details = IEEE80211_RADIOTAP_MCS_HAVE_MCS |
                                          IEEE80211_RADIOTAP_MCS_HAVE_GI |
                                          IEEE80211_RADIOTAP_MCS_HAVE_BW;
-        local->user_power_level = -1;
+        local->user_power_level = IEEE80211_UNSET_POWER_LEVEL;
         wiphy->ht_capa_mod_mask = &mac80211_ht_capa_mod_mask;
 
         INIT_LIST_HEAD(&local->interfaces);