Re: [PATCH] mac80211: Clean up work-queues on disassociation.

[Ben Greear <greearb@candelatech.com>]

On 02/20/2013 06:13 AM, Johannes Berg wrote:
> On Wed, 2013-02-20 at 06:09 -0800, Ben Greear wrote:
>
>>>> @@ -2668,6 +2681,10 @@ static void ieee80211_sta_connection_lost(struct ieee80211_sub_if_data *sdata,
>>>>    			       false, frame_buf);
>>>>    	mutex_unlock(&ifmgd->mtx);
>>>>
>>>> +	/* Have to do this outside the ifmgd->mtx lock. */
>>>> +	cancel_work_sync(&ifmgd->monitor_work);
>>>> +	cancel_work_sync(&ifmgd->beacon_connection_loss_work);
>>>
>>> OTOH, you do this many many times, and that doesn't seem necessary...
>>>
>>> If the work structs run when we disconnected, that's ok, they just
>>> musn't run after we destroy the interface, so I think it'd be much
>>> better to just put the two lines into ieee80211_mgd_stop() instead of
>>> all the other places.
>>
>> Ok, that sounds promising to me.  For that matter, could we just call the sta_quiesce
>> method in mgd_stop?  It would be nice to have all of the final timer and work-queue cleanup
>> in a single place.
>
> That might be interesting, but I think we'd have to clear the
> timer_pending thing afterwards?

Are you talking about this code?

	if (del_timer_sync(&ifmgd->timer))
		set_bit(TMR_RUNNING_TIMER, &ifmgd->timers_running);

	if (del_timer_sync(&ifmgd->chswitch_timer))
		set_bit(TMR_RUNNING_CHANSW, &ifmgd->timers_running);

If so, maybe make a helper method that does all of the first part of the sta_quiesce()
logic, call that from both mgd_stop and the new sta_quiesce() method, and then have
sta_quiesce look like:

         sta_cleanup_timers_and_work();
         if (del_timer_sync(&ifmgd->timer))
		set_bit(TMR_RUNNING_TIMER, &ifmgd->timers_running);

	if (del_timer_sync(&ifmgd->chswitch_timer))
		set_bit(TMR_RUNNING_CHANSW, &ifmgd->timers_running);

?

>
>> And, maybe add some checks in the work-callback methods to bail early if the station
>> isn't connected?
>
> They already do :)

Ok, thanks.

Ben



-- 
Ben Greear <greearb@candelatech.com>
Candela Technologies Inc  http://www.candelatech.com