[PATCH 1/1] drm: i915: don't use OpRegion for XPS 13 IvyBridge

[Ville Syrjälä]

On Thu, Sep 08, 2016 at 12:04:39PM +0200, Martin van Es wrote:
> On dinsdag 6 september 2016 21:40:48 CEST Ville Syrjälä wrote:
> > On Tue, Sep 06, 2016 at 01:56:20PM +0300, Ville Syrjälä wrote:
> > > Actually I just cooked up another branch [2]. It just throws in some
> > > memory barriers to the opregion code, and adds a a new debug print so
> > > to show the response from the BIOS. I'm not too optimistic that the
> > > memory barriers would fix it, but at least we'd get to see the full
> > > response from the BIOS. Can you give this a try?
> > > 
> > > [2] git://github.com/vsyrjala/linux.git opregion_panel_type_stuff
> 
> This kernel doesn't boot (for me).
> 
> I cloned the repo, copied .config from 4.7 kernel, make oldconfig, accepted 
> all defaults and made+installed the kernel. This installed an image 4.0.0-rc7+ 
> (is that correct?) that was unbootable (halts at loading ramdisk).

The version should be 4.7 or 4.8 something. Maybe you used the wrong
branch?

Anywyas I pushed a new branch "opregion_panel_type_quirk" which I'm
hoping will be the final fix we go with. Just waiting for confirmation
that I got the quirk right and that the original machine fixed by the
OpRegion stuff still works. You might want to test that one as well.

-- 
Ville Syrjälä
Intel OTC