Re: mmiotracer hangs the system

[Andy Shevchenko]

On Fri, Oct 14, 2016 at 12:12 AM, Karol Herbst <karolherbst@xxxxxxxxx> wrote:
> sorry for the delay fixing that bug. I got occupied with other things
> and didn't really got to the issue again, it is on my todo list as the
> next item though and I hope I will be able to get a fix ready this
> weekend. I think I might know where the issue is, but didn't confirm
> it yet.

Thanks.I'm still using revert. Feel free to Cc me when you will have
some material to test.

>
> Again, sorry for the delay.
>
> Karol
>
> 2016-08-19 22:46 GMT+02:00 Karol Herbst <karolherbst@xxxxxxxxx>:
>> Hi again,
>>
>> I was able to get a crash/freeze/something while unbinding/binding my
>> nvidia gpu from nouveau.
>>
>> Guess that means something is odd. I will investigate this more over
>> the weekend.
>>
>> 2016-08-19 17:35 GMT+02:00 Andy Shevchenko <andy.shevchenko@xxxxxxxxx>:
>>> On Fri, Aug 19, 2016 at 6:08 PM, karol herbst <karolherbst@xxxxxxxxx> wrote:
>>>> 2016-08-19 15:02 GMT+02:00 Andy Shevchenko <andy.shevchenko@xxxxxxxxx>:
>>>>> On Fri, Aug 19, 2016 at 1:35 PM, karol herbst <karolherbst@xxxxxxxxx> wrote:
>>>>>> is there any update on that issue I missed somehow? I really don't
>>>>>> want to leave the mmiotracer in a state, where it breaks something
>>>>>> while fixing other issues.
>>>>>
>>>>> No updates. I'm busy right now with more priority tasks and revert
>>>>> works for me. Issue is reproducible in my case 100%.
>>>>>
>>>>
>>>> Is there something I could do with a "normal" haswell desktop system
>>>> to reproduce this issue?
>>>
>>> Try LPSS UART device(s)
>>>
>>>>
>>>> I'll try to play around the next days a bit and maybe I find something
>>>> that works out here as well. It seems to be related to
>>>> unmapping-mapping cycles.
>>>
>>> That is the only thing I would think of.
>>>
>>>>
>>>> Because if this only happens with the pwm-lpss driver,
>>>
>>> It has nothing to do with pwm-lpss since it's a HS UART and served by
>>> intel-lpss driver.
>>>
>>>> it may be
>>>> really troublesome to debug, because I don't really know the code that
>>>> well to be sure where the issue might be.
>>>>
>>>>> So, I would able to attach dmesg in case it would be helpful.
>>>>> Otherwise tell me exact instructions how to debug the issue.
>>>>>
>>>>> Here you are:
>>>>> http://pastebin.com/raw/VfTZENt7
>>>>>
>>>>>> But for now, without being able to even reproduce the issue, I can't
>>>>>> really do much, because the code in the current state looks sane to
>>>>>> me. Maybe this case includes the mmiotracer cleaning things up and
>>>>>> arms new region for mmiotracing and that's why it fails? Besides that,
>>>>>> I have no idea and no way to reproduce this, so I can't help this way.
>>>>>
>>>>> Maybe. First thing happened is iounmap().
>>>
>>>
>>> --
>>> With Best Regards,
>>> Andy Shevchenko



-- 
With Best Regards,
Andy Shevchenko