[Intel-gfx] IVB-eDP regression with on latest git

[Oleksij Rempel]

Am 14.10.2012 10:55, schrieb Daniel Vetter:
> On Sun, Oct 14, 2012 at 9:18 AM, Oleksij Rempel
> <bug-track at fisher-privat.net> wrote:
>> With latest kernel (vanilla/master, or intel.drm-next) i do not have image
>> on build in screen (eDP). Hardware Asus Zenbook UX32A. Vendor: 0x8086,
>> Device: 0x0166, Revision: 0x09 (??)
>> Is it know issue?
>
> Nope, this is a new one. Can you grab the dmesg with drm.debug=0xe of
> the broken kernel please? Also, a bisect usually helps a lot, too.
>
> Thanks, Daniel
>


I can't access this laptop with broken kernel.

The patch caused this regression is:
commit 2477367083b3eaa97f87993ab26627a02f350551
Author: Chris Wilson <chris at chris-wilson.co.uk>
Date:   Wed Sep 26 16:48:30 2012 +0100

     drm/i915: Try harder to complete DP training pattern 1

     In commit cdb0e95bf571dccc1f75fef9bdad21b167ef0b37
     Author: Keith Packard <keithp at keithp.com>
     Date:   Tue Nov 1 20:00:06 2011 -0700

         drm/i915: Try harder during dp pattern 1 link training

     extra passes were made to retry the same voltage and then retry a full
     clock reset. However, as coverity pointed out, we never tried the full
     clock reset as we broke out of the loop early.

     Signed-off-by: Chris Wilson <chris at chris-wilson.co.uk>
     Reviewed-by: Damien Lespiau <damien.lespiau at intel.com>


Reverting it makes laptop work again.

-- 
Regards,
Oleksij