[yocto] Kernel bug 109051

[Chris Tapp]

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.

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 ;-)

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

--

Chris Tapp
opensource at keylevel.com
www.keylevel.com