Re: [Bug #13337] [post 2.6.29 regression] hang during suspend of b44/b43 modules

Jan Scholz
2009-07-11T17:21:09Z

Johannes Berg <johannes@sipsolutions.net> writes:

> On Sat, 2009-07-11 at 16:07 +0200, Jan Scholz wrote:
>
>> > Jan, can you run with console_suspend=0 (or whatever it is now, Rafael
>> > will correct me if I'm wrong) that should work on your platform, and put
>> > a bunch of printk calls into __ieee80211_suspend in net/mac80211/pm.c to
>> > see where in there it's hanging?
>>
>> Did that, seems like it hangs in
>> drv_remove_interface(local, &conf);
>
> Ok, thanks! I was going to suggest doing the same in
> b43_op_remove_interface in drivers/net/wireless/b43/main.c, but I think
> the problem is just that we have an ordering problem and call drv_stop
> before drv_remove_interface. I'll try to come up with a fix soon --
> might not be able to today though, in the meantime I guess you can just
> move the drv_stop call to the end of the function and tell me if that
> works -- that would be racy but should be ok most of the time.

I moved drv_stop to the end of the function (see patch below) and now
suspend works fine.

Jan

diff --git a/net/mac80211/pm.c b/net/mac80211/pm.c
index 7a549f9..0ac15fb 100644
--- a/net/mac80211/pm.c
+++ b/net/mac80211/pm.c
@@ -58,12 +58,6 @@ int __ieee80211_suspend(struct ieee80211_hw *hw)
/* flush again, in case driver queued work */
flush_workqueue(local->hw.workqueue);

- /* stop hardware - this must stop RX */
- if (local->open_count) {
- ieee80211_led_radio(local, false);
- drv_stop(local);
- }
-
/* remove STAs */
spin_lock_irqsave(&local->sta_lock, flags);
list_for_each_entry(sta, &local->sta_list, list) {
@@ -111,6 +105,12 @@ int __ieee80211_suspend(struct ieee80211_hw *hw)
drv_remove_interface(local, &conf);
}

+ /* stop hardware - this must stop RX */
+ if (local->open_count) {
+ ieee80211_led_radio(local, false);
+ drv_stop(local);
+ }
+
local->suspended = true;
local->quiescing = false;