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, 38 insertions, 0 deletions

diff --git a/net/mac80211/iface.c b/net/mac80211/iface.c
index 1a6fe135f20..80ce90b29d9 100644
--- a/net/mac80211/iface.c
+++ b/net/mac80211/iface.c
@@ -42,6 +42,41 @@
  * by either the RTNL, the iflist_mtx or RCU.
  */
 
+bool __ieee80211_recalc_txpower(struct ieee80211_sub_if_data *sdata)
+{
+	struct ieee80211_chanctx_conf *chanctx_conf;
+	int power;
+
+	rcu_read_lock();
+	chanctx_conf = rcu_dereference(sdata->vif.chanctx_conf);
+	if (!chanctx_conf) {
+		rcu_read_unlock();
+		return false;
+	}
+
+	power = chanctx_conf->channel->max_power;
+	rcu_read_unlock();
+
+	if (sdata->user_power_level != IEEE80211_UNSET_POWER_LEVEL)
+		power = min(power, sdata->user_power_level);
+
+	if (sdata->ap_power_level != IEEE80211_UNSET_POWER_LEVEL)
+		power = min(power, sdata->ap_power_level);
+
+	if (power != sdata->vif.bss_conf.txpower) {
+		sdata->vif.bss_conf.txpower = power;
+		ieee80211_hw_config(sdata->local, 0);
+		return true;
+	}
+
+	return false;
+}
+
+void ieee80211_recalc_txpower(struct ieee80211_sub_if_data *sdata)
+{
+	if (__ieee80211_recalc_txpower(sdata))
+		ieee80211_bss_info_change_notify(sdata, BSS_CHANGED_TXPOWER);
+}
 
 static u32 ieee80211_idle_off(struct ieee80211_local *local,
 			      const char *reason)
@@ -1510,6 +1545,9 @@ int ieee80211_if_add(struct ieee80211_local *local, const char *name,
 
 	ieee80211_set_default_queues(sdata);
 
+	sdata->ap_power_level = IEEE80211_UNSET_POWER_LEVEL;
+	sdata->user_power_level = local->user_power_level;
+
 	/* setup type-dependent data */
 	ieee80211_setup_sdata(sdata, type);