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

[Daniel Vetter]

On Mon, Oct 15, 2012 at 09:07:33PM +0200, Oleksij Rempel wrote:
> I'll repost it, looks like last message got lost.
> 
> Am 14.10.2012 14:49, schrieb 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.

Ok, I've reverted this in -fixes, we need to think a bit more about our dp
link training for -next. Thanks a lot for reporting and bisecting this
regression.

Yours, Daniel
-- 
Daniel Vetter
Software Engineer, Intel Corporation
+41 (0) 79 365 57 48 - http://blog.ffwll.ch