Re: 4.9.62: intermittent flicker after upgrade from 4.9.61

[Rainer Fiebig <jrf@mailbox.org>]

Greg KH wrote:
> On Sat, Nov 18, 2017 at 05:08:20PM +0100, Rainer Fiebig wrote:
>> Greg KH wrote:
>>> On Sat, Nov 18, 2017 at 01:47:32PM +0100, Rainer Fiebig wrote:
>>>> Hi!
>>>>
>>>> Hopefully the right addressee.
>>>>
>>>> Encountered two bad backports which cause screen-flicker.
>>>> dmesg shows:
>>>>
>>>> ...
>>>> [drm:ironlake_irq_handler [i915]] *ERROR* CPU pipe A FIFO underrun
>>>> [drm:ironlake_irq_handler [i915]] *ERROR* PCH transcoder A FIFO underrun
>>>> [drm:ironlake_irq_handler [i915]] *ERROR* CPU pipe B FIFO underrun
>>>> [drm:ironlake_irq_handler [i915]] *ERROR* PCH transcoder B FIFO underrun
>>>> ...
>>>>
>>>> CPU: Intel Core i3 (Clarkdale/Ironlake)
>>>>
>>>> The backports are:
>>>>
>>>> - diff --git a/drivers/gpu/drm/i915/intel_pm.c
>>>> b/drivers/gpu/drm/i915/intel_pm.c
>>>>     index 49de476..277a802 100644
>>>> - diff --git a/drivers/gpu/drm/i915/intel_drv.h
>>>> b/drivers/gpu/drm/i915/intel_drv.h
>>>>     index a19ec06..3ce9ba3 100644
>>>>
>>>> After reversing them the flicker is gone, no more messages in dmesg. All
>>>> else OK so far.
>>>
>>> So which commit was the one that caused the problem?  I will be glad to
>>> revert it.
>>>
>>> thanks,
>>>
>>> greg k-h
>>>
>>>
>>
>> I started by reverting the more complex one first ("index
>> 49de476..277a802100644"). But the kernel wouldn't compile then.
> 
> What git commit id is that?  I don't see those ids in the 4.9-stable
> tree.
> 
>> So I also reverted "index a19ec06..3ce9ba3 100644". After that the
>> kernel compiled just fine and the problems were gone (still are).
> 
> Same here, what git commit id was this?
> 
> thanks,
> 
> greg k-h
> 

Please wait a moment. I'm checking whether I've made a mistake here.