Re: [Bug #15127] Bluetooth: sleeping function called from invalid context

David John
2010-02-02T05:17:46Z

On 02/02/2010 12:44 AM, Marcel Holtmann wrote:
> Hi David,
>
>>>> This message has been generated automatically as a part of a report
>>>> of regressions introduced between 2.6.31 and 2.6.32.
>>>>
>>>> The following bug entry is on the current list of known regressions
>>>> introduced between 2.6.31 and 2.6.32. Please verify if it still should
>>>> be listed and let me know (either way).
>>>>
>>>>
>>>> Bug-Entry : http://bugzilla.kernel.org/show_bug.cgi?id=15127
>>>> Subject : Bluetooth: sleeping function called from invalid context
>>>> Submitter : David John <davidjon-XRr60H37pjdAfugRpC6u6w@public.gmane.org>
>>>> Date : 2010-01-12 9:19 (20 days old)
>>>> First-Bad-Commit: http://git.kernel.org/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commit;h=9e726b17422bade75fba94e625cd35fd1353e682
>>>> References : http://marc.info/?l=linux-kernel&m=126328727021949&w=4
>>>
>>> you have an outdated email from Luiz and I change it to the right one
>>> now.
>>>
>>> I looked with him at the patch and I think this will fix it:
>>>
>>> diff --git a/net/bluetooth/rfcomm/core.c b/net/bluetooth/rfcomm/core.c
>>> index fc5ee32..2b50637 100644
>>> --- a/net/bluetooth/rfcomm/core.c
>>> +++ b/net/bluetooth/rfcomm/core.c
>>> @@ -252,7 +252,6 @@ static void rfcomm_session_timeout(unsigned long
>>> arg)
>>> BT_DBG("session %p state %ld", s, s->state);
>>>
>>> set_bit(RFCOMM_TIMED_OUT, &s->flags);
>>> - rfcomm_session_put(s);
>>> rfcomm_schedule(RFCOMM_SCHED_TIMEO);
>>> }
>>>
>>> @@ -1920,6 +1919,7 @@ static inline void rfcomm_process_sessions(void)
>>> if (test_and_clear_bit(RFCOMM_TIMED_OUT, &s->flags)) {
>>> s->state = BT_DISCONN;
>>> rfcomm_send_disc(s, 0);
>>> + rfcomm_session_put(s);
>>> continue;
>>> }
>>>
>>> We need some extra testing on this with the actual hardware we did the
>>> patch for. So this will take at least a few days before we get our hands
>>> on it.
>>
>> FWIW, your patch fixes the issue.
>
> nice. So I can add a tested-by line to the final patch?

Sure,

Tested-by: David John <davidjon-XRr60H37pjdAfugRpC6u6w@public.gmane.org>

>
> Just our of curiosity, which hardware did you test this with.

I have an inbuilt (laptop) USB Dell Wireless 365 Bluetooth Module
(413c:8160). I can send more info about the device if you want.

> We only know about one headset that should cause this issue.

That's weird. I assumed it would happen for any device, since
rfcomm_session_add is called from multiple places and it adds
rfcomm_session_timeout on a timer which will cause the trace
if the timer fires.

I could be wrong though.

Regards,
David.

>
> Regards
>
> Marcel
>
>
>