Bug 67950

I have the same machine and it seems to still work here. So no idea what's gone boink. Can you please try to bisect this regression?

Will try next week, thanks.  In the mean time could you please verify any of http://en.altlinux.org/Regular#main live images which happen to use the same 3.10.5 by now?

3.11-rc4 misbehaves the same way here, just in case.  And even worse -- four tuxen with windows flags!!1

(In reply to comment #1)
> I have the same machine and it seems to still work here. So no idea what's
> gone boink.
Do you run it in BIOS or UEFI mode?
efifb gets initialized first here as mentioned in dmesg attached.

> Can you please try to bisect this regression?
Yup (thanks boyarsh@altlinux); git bisect log:
# bad: [8bb495e3f02401ee6f76d1b1d77f3ac9f079e376] Linux 3.10
# good: [c1be5a5b1b355d40e6cf79cc979eb66dafa24ad1] Linux 3.9
git bisect start 'v3.10' 'v3.9' '--' 'drivers/gpu/drm/i915/'
# bad: [8a5c2ae753c588bcb2a4e38d1c6a39865dbf1ff3] drm/i915: fix ILK GPU reset for render
git bisect bad 8a5c2ae753c588bcb2a4e38d1c6a39865dbf1ff3
# good: [ed5de3995f9cdff997613f240e41033463703121] drm/i915: add media well to VLV force wake routines v2
git bisect good ed5de3995f9cdff997613f240e41033463703121
# good: [fa00abe00e379a0e9b070616baee58692576f29e] DRM/i915: Remove valleyview_hpd_irq_setup.
git bisect good fa00abe00e379a0e9b070616baee58692576f29e
# good: [460da91617d870972a7ae300fad3e13731b67757] drm/i915: compute pipe_config earlier
git bisect good 460da91617d870972a7ae300fad3e13731b67757
# bad: [3600836585e3fdef0a1410d63fe5ce4015007aac] drm/i915: convert DP autodither code to new infrastructure  
git bisect bad 3600836585e3fdef0a1410d63fe5ce4015007aac
# good: [5bfe2ac00395ca37219b7187299cd9d23ae06682] drm/i915: add pipe_config->has_pch_encoder
git bisect good 5bfe2ac00395ca37219b7187299cd9d23ae06682
# good: [965e0c489f360df1beeb567e4540777a09b8896e] drm/i915: introduce pipe_config->dither|pipe_bpp
git bisect good 965e0c489f360df1beeb567e4540777a09b8896e
# good: [4e53c2e010e531b4a014692199e978482d471c7e] drm/i915: precompute pipe bpp before touching the hw
git bisect good 4e53c2e010e531b4a014692199e978482d471c7e
# first bad commit: [3600836585e3fdef0a1410d63fe5ce4015007aac] drm/i915: convert DP autodither code to new
infrastructure

Seems that there's no image (kas@ advised to shine a flashlight upon the display, there were no signs of display manager upon boot when the network was up already).

(In reply to comment #2)
> could you please verify any of http://en.altlinux.org/Regular#main
> live images which happen to use the same 3.10.5 by now?
Maybe this helps: today's snapshot including 3.10.6 just works on my UX31A in both BIOS and UEFI modes *if* CSM is enabled in firmware; disabling Boot > Launch CSM triggers the bug.

The images are UEFI/BIOS, CD/Flash hybrid (just dd it onto a stick).

(In reply to comment #5)
> [...] 3.10.6 just works on my UX31A [...] *if* CSM is enabled in firmware
Confirmed by the original (ALT) bug poster too.

3.10.7 plus the hack from https://bugzilla.kernel.org/show_bug.cgi?id=59841#c41 works on UX31A with CSM disabled.

Please retest with latest drm-intel-fixes, specifically

commit 2e6efddd203c15ca5c4700511f717c0e9a3ea31a
Author: Imre Deak <imre.deak@intel.com>
Date:   Fri Aug 23 23:50:23 2013 +0300

    drm/i915: ivb: fix edp voltage swing reg val

Michael, just to verify what's seen on [1] and [2], please attach /sys/kernel/debug/dri/0/i915_opregion for non-working and working setting of the BIOS option. Thanks.

[1] https://bugzilla.kernel.org/show_bug.cgi?id=59841
[2] https://bugzilla.kernel.org/show_bug.cgi?id=60881

(In reply to comment #9)
> please attach /sys/kernel/debug/dri/0/i915_opregion for non-working
> and working setting of the BIOS option
OK, I'll have to get to the office so another console with ssh is handy.

Jani, I've posted /sys/kernel/debug/dri/0/i915_opregion for UX31A (both UEFI and UEFI+CSM) at kernel bugzilla so as to keep all dumps to one bug:

https://bugzilla.kernel.org/show_bug.cgi?id=59841#c148 (heh, got striped)
https://bugzilla.kernel.org/attachment.cgi?id=108031
https://bugzilla.kernel.org/attachment.cgi?id=108051

I'll repost these here if you tell me to of course.

Daniel, I haven't had a chance to retest with latest drm-intel-fixes so far, sorry.  Should I try this week?

Yes, as I wonder if this is something like 

commit fd4daa9cea025ddf8623db289e79d264e9fa66f6
Author: Chris Wilson <chris@chris-wilson.co.uk>
Date:   Tue Aug 27 17:04:17 2013 +0100

    drm/i915: Track pfit enable state separately from size

instead of the usual issues.

(In reply to comment #12)
> Yes, as I wonder if this is something like 
> 
> commit fd4daa9cea025ddf8623db289e79d264e9fa66f6
> Author: Chris Wilson <chris@chris-wilson.co.uk>
> Date:   Tue Aug 27 17:04:17 2013 +0100
> 
>     drm/i915: Track pfit enable state separately from size
> 
> instead of the usual issues.

Chris, the VBT reports different bpp for CSM vs. no-CSM. One works, the other doesn't. How would that commit be relevant here?

Less likely in that case... Still worth checking if it is.

Fixed by
commit c6cd2ee2d59111a07cd9199564c9bdcb2d11e5cf
Author: Jani Nikula <jani.nikula@intel.com>
Date:   Mon Oct 21 10:52:07 2013 +0300

    drm/i915/dp: workaround BIOS eDP bpp clamping issue