[meta-intel] [yocto] Kernel bug 109051

[Bruce Ashfield]

On 2016-07-25 2:47 AM, Chris Tapp wrote:
> Hi Bruce,
>
>> On 25 Jul 2016, at 03:40, Bruce Ashfield <bruce.ashfield at windriver.com> wrote:
>>
>> On 2016-07-24 6:09 PM, Chris Tapp wrote:
>>> I’m using the meta-intel “valley-island” BSP under “krogoth” and think I may have run into https://bugzilla.kernel.org/show_bug.cgi?id=109051.
>>>
>>> I’m using a J1900 (listed as affected) and the system locks up totally (running a graphics-based application) after an indeterminate period.
>>>
>>> Using the scripts referenced on the related bug page for comment 437 (https://bugzilla.kernel.org/show_bug.cgi?id=109051#c437) appears to resolve the issue.
>>>
>>> Is anyone aware of this and/or know if it will be fixed within the Yocto kernel tree?
>> Not unless someone sends a patch.
>>
>> If you have a platform showing the error, and have tested a fix .. why
>> not just send the patch ?
> Thanks Bruce,
>
> Unfortunately, I’ve not found one yet. The scripts I mention just disable c-states as the problem seems to be an interaction between the i915 driver and power management. I can probably live with this for my application, but it still lives a window during boot and the script running where a lockup could happen - unlikely, as the bug thread implies the problem is more likely to show when the system has idle CPU resources.

Aha. Sorry about that. I misread your description to mean you had a fix.

So my answer should have been: "I'm not aware of the issue, or a fix that
is in flight".

>  From the thread it looks as if it may be possible to produce a patch as there are reportes that the problem may be fixed / does not show in later kernel versions (4.6?), but it also looks as if there may be more than one patch required (in different areas).
>
> I’ll have a dig, see what I can find and try to produce a patch set - I’m not a kernel expert, so it may take some time ;-)

Did you log a issue in bugzilla against meta-intel ? That's a good way to
get more eyes on a problem (depending on the current load of issues).

Bruce

>
>> Bruce
>>
>>> --
>>>
>>> Chris Tapp
>>> opensource at keylevel.com
>>> www.keylevel.com
>>>
> --
>
> Chris Tapp
> opensource at keylevel.com
> www.keylevel.com
>