mac80211: cancel/restart all timers across suspend/resume

We forgot to cancel all timers in mac80211 when suspending.
In particular we forgot to deal with some things that can
cause hardware reconfiguration -- while it is down.

While at it we go ahead and add a warning in ieee80211_sta_work()
if its run while the suspend->resume cycle is in effect. This
should not happen and if it does it would indicate there is
a bug lurking in either mac80211 or mac80211 drivers.

With this now wpa_supplicant doesn't blink when I go to suspend
and resume where as before there where issues with some timers
running during the suspend->resume cycle. This caused a lot of
incorrect assumptions and would at times bring back the device
in an incoherent, but mostly recoverable, state.

Signed-off-by: Luis R. Rodriguez <lrodriguez@atheros.com>
Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

1 files changed, 18 insertions, 0 deletions

diff --git a/net/mac80211/scan.c b/net/mac80211/scan.c
index e65d74ba404..2a8d09ad17f 100644
--- a/net/mac80211/scan.c
+++ b/net/mac80211/scan.c
@@ -631,3 +631,21 @@ int ieee80211_request_internal_scan(struct ieee80211_sub_if_data *sdata,
 	mutex_unlock(&local->scan_mtx);
 	return ret;
 }
+
+void ieee80211_scan_cancel(struct ieee80211_local *local)
+{
+	bool swscan;
+
+	cancel_delayed_work_sync(&local->scan_work);
+
+	/*
+	 * Only call this function when a scan can't be
+	 * queued -- mostly at suspend under RTNL.
+	 */
+	mutex_lock(&local->scan_mtx);
+	swscan = local->sw_scanning;
+	mutex_unlock(&local->scan_mtx);
+
+	if (swscan)
+		ieee80211_scan_completed(&local->hw, true);
+}