mac80211: resume properly, add suspend/resume test

When mac80211 resumes, it currently doesn't reconfigure the interfaces
entirely and also doesn't reconfigure BSS information -- fix this.

Also, to be able to test this, add a debugfs file that just calls
the suspend/resume code to see what happens when we go through that,
without needing the time-consuming suspend/resume cycle.

(Original version broke the build for CONFIG_PM=n.  Define alternative
functions for that situation. -- JWL)

Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
diff --git a/net/mac80211/pm.c b/net/mac80211/pm.c
index 1e6152a..0273023 100644
--- a/net/mac80211/pm.c
+++ b/net/mac80211/pm.c
@@ -143,6 +143,35 @@
 	ieee80211_configure_filter(local);
 	netif_addr_unlock_bh(local->mdev);
 
+	/* Finally also reconfigure all the BSS information */
+	list_for_each_entry(sdata, &local->interfaces, list) {
+		u32 changed = ~0;
+		if (!netif_running(sdata->dev))
+			continue;
+		switch (sdata->vif.type) {
+		case NL80211_IFTYPE_STATION:
+			/* disable beacon change bits */
+			changed &= ~IEEE80211_IFCC_BEACON;
+			/* fall through */
+		case NL80211_IFTYPE_ADHOC:
+		case NL80211_IFTYPE_AP:
+		case NL80211_IFTYPE_MESH_POINT:
+			WARN_ON(ieee80211_if_config(sdata, changed));
+			ieee80211_bss_info_change_notify(sdata, ~0);
+			break;
+		case NL80211_IFTYPE_WDS:
+			break;
+		case NL80211_IFTYPE_AP_VLAN:
+		case NL80211_IFTYPE_MONITOR:
+			/* ignore virtual */
+			break;
+		case NL80211_IFTYPE_UNSPECIFIED:
+		case __NL80211_IFTYPE_AFTER_LAST:
+			WARN_ON(1);
+			break;
+		}
+	}
+
 	ieee80211_wake_queues_by_reason(hw,
 			IEEE80211_QUEUE_STOP_REASON_SUSPEND);