mac80211: simplify idle handling

Now that we have channel contexts, idle is (pretty
much) equivalent to not having a channel context.
Change the code to use this relation so that there
no longer is a need for a lot of idle recalculate
calls everywhere.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
diff --git a/net/mac80211/chan.c b/net/mac80211/chan.c
index b5b5076..038f249 100644
--- a/net/mac80211/chan.c
+++ b/net/mac80211/chan.c
@@ -91,6 +91,10 @@
 
 	list_add_rcu(&ctx->list, &local->chanctx_list);
 
+	mutex_lock(&local->mtx);
+	ieee80211_recalc_idle(local);
+	mutex_unlock(&local->mtx);
+
 	return ctx;
 }
 
@@ -110,6 +114,10 @@
 
 	list_del_rcu(&ctx->list);
 	kfree_rcu(ctx, rcu_head);
+
+	mutex_lock(&local->mtx);
+	ieee80211_recalc_idle(local);
+	mutex_unlock(&local->mtx);
 }
 
 static int ieee80211_assign_vif_chanctx(struct ieee80211_sub_if_data *sdata,
@@ -128,6 +136,8 @@
 	ctx->refcount++;
 
 	ieee80211_recalc_txpower(sdata);
+	sdata->vif.bss_conf.idle = false;
+	ieee80211_bss_info_change_notify(sdata, BSS_CHANGED_IDLE);
 
 	return 0;
 }
@@ -175,6 +185,9 @@
 	ctx->refcount--;
 	rcu_assign_pointer(sdata->vif.chanctx_conf, NULL);
 
+	sdata->vif.bss_conf.idle = true;
+	ieee80211_bss_info_change_notify(sdata, BSS_CHANGED_IDLE);
+
 	drv_unassign_vif_chanctx(local, sdata, ctx);
 
 	if (ctx->refcount > 0) {