cfg80211/mac80211: use reduced txpower for 5 and 10 MHz

Some regulations (like germany, but also FCC) express their transmission
power limit in dBm/MHz or mW/MHz. To cope with that and be on the safe
side, reduce the maximum power to half (10 MHz) or quarter (5 MHz)
when operating on these reduced bandwidth channels.

Signed-off-by: Simon Wunderlich <siwu@hrz.tu-chemnitz.de>
Signed-off-by: Mathias Kretschmer <mathias.kretschmer@fokus.fraunhofer.de>
Signed-off-by: Johannes Berg <johannes@sipsolutions.net>

3 files changed, 4 insertions, 3 deletions

diff --git a/net/mac80211/iface.c b/net/mac80211/iface.c
index cc117591f678..4c41c11958c8 100644
--- a/net/mac80211/iface.c
+++ b/net/mac80211/iface.c
@@ -54,7 +54,7 @@ bool __ieee80211_recalc_txpower(struct ieee80211_sub_if_data *sdata)
                 return false;
         }
 
-        power = chanctx_conf->def.chan->max_power;
+        power = ieee80211_chandef_max_power(&chanctx_conf->def);
         rcu_read_unlock();
 
         if (sdata->user_power_level != IEEE80211_UNSET_POWER_LEVEL)
diff --git a/net/mac80211/main.c b/net/mac80211/main.c
index 091088ac7890..6da98c77496b 100644
--- a/net/mac80211/main.c
+++ b/net/mac80211/main.c
@@ -151,7 +151,7 @@ static u32 ieee80211_hw_conf_chan(struct ieee80211_local *local)
                 changed |= IEEE80211_CONF_CHANGE_SMPS;
         }
 
-        power = chandef.chan->max_power;
+        power = ieee80211_chandef_max_power(&chandef);
 
         rcu_read_lock();
         list_for_each_entry_rcu(sdata, &local->interfaces, list) {
diff --git a/net/mac80211/mlme.c b/net/mac80211/mlme.c
index f7552c2b74eb..211246b46819 100644
--- a/net/mac80211/mlme.c
+++ b/net/mac80211/mlme.c
@@ -747,7 +747,8 @@ static void ieee80211_send_assoc(struct ieee80211_sub_if_data *sdata)
                 *pos++ = WLAN_EID_PWR_CAPABILITY;
                 *pos++ = 2;
                 *pos++ = 0; /* min tx power */
-                *pos++ = chan->max_power; /* max tx power */
+                 /* max tx power */
+                *pos++ = ieee80211_chandef_max_power(&chanctx_conf->def);
 
                 /* 2. supported channels */
                 /* TODO: get this in reg domain format */