[Intel-gfx] 3.14.3 i915 dead display under X11

[Josh Boyer]

On Wed, May 14, 2014 at 3:33 PM, Greg KH <gregkh at linuxfoundation.org> wrote:
> On Wed, May 14, 2014 at 09:19:32PM +0200, Daniel Vetter wrote:
>> On Wed, May 14, 2014 at 08:47:38PM +0200, Bruno Prémont wrote:
>> > CCing intel-gfx as otherwise it will probably not get seen by developers.
>> >
>> > On Sun, 11 May 2014 Carbonated Beverage <ramune at psychosnugglebunnies.net> wrote:
>> > > Bisecting from 3.13.6 (good) to 3.14.3 (bad) ended up with...
>> > >
>> > > commit b35684b8fa94e04f55fd38bf672b737741d2f9e2
>> > > Author: Jani Nikula <jani.nikula at intel.com>
>> > > Date:   Thu Nov 14 12:13:41 2013 +0200
>> > >
>> > >     drm/i915: do full backlight setup at enable time
>> > >
>> > >     We should now have all the information we need to do a full
>> > >     initialization of the backlight registers.
>> > >
>> > >     v2: Keep QUIRK_NO_PCH_PWM_ENABLE for now (Imre).
>> > >
>> > >     Signed-off-by: Jani Nikula <jani.nikula at intel.com>
>> > >     Reviewed-by: Imre Deak <imre.deak at intel.com>
>> > >     Signed-off-by: Daniel Vetter <daniel.vetter at ffwll.ch>
>> > >
>> > > Which is in 3.12.0????
>> > >
>> > > I'm not sure how that came to be.  Does that look right?  What other
>> > > information would be required to track this down?
>>
>> We've killed this again in 3.14 since we've hoped the backlight rework in
>> there fixed it. For 3.15 we finally have the right fix - vbt has a bit
>> telling us not to look at the integrated PWM for the panel.
>>
>> For 3.14 we will (again) resurrect the quirk because the vbt thing is a
>> bit too risky an imo needs a full -rc cycle for testing. But that revert
>> is currently stalled because Greg KH is travelling too much ;-)
>>
>> Cc'ing him to make sure that patch doesn't miss the next 3.14.x release.
>
> What specific patch are you wanting to make sure makes it in?  I've been

Subject: [PATCH for stable 3.14 only 0/1] drm/i915: restore
QUIRK_NO_PCH_PWM_ENABLE

> avoiding all of the drm patches so far for 3.14.y as it's an easy thing
> to do, but I'll eventually have to start paying attention to them :)

Jani has bugged you twice about it I think.  You've said it's not lost
both times.  Third time is a charm?

josh