diff mbox

[03/10] mac80211: use freezable workqueue for restart work

Message ID 1445763582-11421-3-git-send-email-emmanuel.grumbach@intel.com
State Accepted
Delegated to: Johannes Berg
Headers show

Commit Message

Emmanuel Grumbach Oct. 25, 2015, 8:59 a.m. UTC
From: Eliad Peller <eliad@wizery.com>

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 <eliadx.peller@intel.com>
Signed-off-by: Emmanuel Grumbach <emmanuel.grumbach@intel.com>
 net/mac80211/main.c |  2 +-
 net/mac80211/util.c | 11 +++++++++++
 2 files changed, 12 insertions(+), 1 deletion(-)


Johannes Berg Nov. 3, 2015, 9:37 a.m. UTC | #1
On Sun, 2015-10-25 at 10:59 +0200, Emmanuel Grumbach wrote:
> From: Eliad Peller <eliad@wizery.com>
> Requesting hw restart during suspend might result
> in the restart work being executed after mac80211
> and the hw are suspended.

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diff mbox


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;
-	schedule_work(&local->restart_work);
+	queue_work(system_freezable_wq, &local->restart_work);
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 <jbenc@suse.cz>
  * Copyright 2007	Johannes Berg <johannes@sipsolutions.net>
  * 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)
+	 * 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