From: Eliad Peller <[email protected]>
Requesting hw restart during suspend might result
in the restart work being executed after mac80211
and the hw are suspended.
Solve the race by simply scheduling the restart
work on a freezable workqueue.
Note that there can be some cases of reconfiguration
on resume (besides the hardware restart):
* wowlan is not configured -
All the interfaces removed were removed on suspend,
and drv_stop() was called. At this point the driver
shouldn't expect for hw_restart anyway, so we can
simply cancel it (on resume).
* wowlan is configured, drv_resume() == 1
There is no definitive expected behavior in this case,
as each driver might have different expectations (e.g.
setting some flags on suspend/restart vs. not handling
spurious recovery).
For now, simply let the hw_restart work run again after
resume, and hope the driver will handle it well (or at
least initiate another hw restart).
Signed-off-by: Eliad Peller <[email protected]>
Signed-off-by: Emmanuel Grumbach <[email protected]>
---
net/mac80211/main.c | 2 +-
net/mac80211/util.c | 11 +++++++++++
2 files changed, 12 insertions(+), 1 deletion(-)
diff --git a/net/mac80211/main.c b/net/mac80211/main.c
index 273c96d..858f6b1 100644
--- a/net/mac80211/main.c
+++ b/net/mac80211/main.c
@@ -281,7 +281,7 @@ void ieee80211_restart_hw(struct ieee80211_hw *hw)
local->in_reconfig = true;
barrier();
- schedule_work(&local->restart_work);
+ queue_work(system_freezable_wq, &local->restart_work);
}
EXPORT_SYMBOL(ieee80211_restart_hw);
diff --git a/net/mac80211/util.c b/net/mac80211/util.c
index 7150ae2..e936acd 100644
--- a/net/mac80211/util.c
+++ b/net/mac80211/util.c
@@ -4,6 +4,7 @@
* Copyright 2006-2007 Jiri Benc <[email protected]>
* Copyright 2007 Johannes Berg <[email protected]>
* Copyright 2013-2014 Intel Mobile Communications GmbH
+ * Copyright (C) 2015 Intel Deutschland GmbH
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
@@ -1754,6 +1755,16 @@ int ieee80211_reconfig(struct ieee80211_local *local)
#endif
/*
+ * In case of hw_restart during suspend (without wowlan),
+ * cancel restart work, as we are reconfiguring the device
+ * anyway.
+ * Note that restart_work is scheduled on a frozen workqueue,
+ * so we can't deadlock in this case.
+ */
+ if (suspended && local->in_reconfig && !reconfig_due_to_wowlan)
+ cancel_work_sync(&local->restart_work);
+
+ /*
* Upon resume hardware can sometimes be goofy due to
* various platform / driver / bus issues, so restarting
* the device may at times not work immediately. Propagate
--
2.1.4
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