Fwd: EDID/DP fixes for proper bpc detection of displays.

[Daniel Vetter]

On Sat, Jul 30, 2016 at 05:08:03PM +0200, Mario Kleiner wrote:
> Three weeks have passed, so resending. Could i maybe excite somebody to
> review/merge at least some of the really trivial but important patches to
> fix regressions back-ported to all stable kernels, mostly in Intel kms + DP
> legacy in this series before the 4.8 merge window closes?
> 
> Especially patch 2, "[PATCH 2/5] drm/i915/dp: Revert "drm/i915/dp: fall back
> to 18 bpp when sink capability is unknown" a revert acked by Jani for a
> patch of him, and patch 5 "[PATCH 5/5] drm/edid: Set 8 bpc color depth for
> displays with "DFP 1.x compliant TMDS"?
> 
> Patch 5/5 would make our EDID parsing for DVI more complete and if also
> back-ported to stable would at least prevent the worst fallout for current
> users if patch 2/5 doesn't get applied.

I don't have the spec handy to review the details, but it all seems to
make sense. Ack: me.

Dave, probably simplest if you just pick up the entire pile into drm-fixes
directly? Or still offline because cold, and I should carry it in
drm-fixes?
-Daniel

> 
> thanks,
> -mario
> 
> -------- Forwarded Message --------
> Subject: EDID/DP fixes for proper bpc detection of displays.
> Date: Wed,  6 Jul 2016 12:05:43 +0200
> From: Mario Kleiner <mario.kleiner.de at gmail.com>
> To: dri-devel at lists.freedesktop.org
> CC: mario.kleiner.de at gmail.com
> 
> Updated series to fix the regressions introduced into stable
> kernels for active Displayport to dual-link DVI converters and
> for active Displayport to VGA converters. Also to fix this stuff
> better for Linux 4.8.
> 
> Patch 1 + 2 are needed to fix the regressions in the stable
> kernels. These are meant for easy backporting to all affected
> kernels.
> 
> Patch 3: A DP helper for parsing sink bpc from DP aux data to
> assist drivers if they can't get bpc from EDID.
> 
> Patch 4: Make intel kms use patch 3.
> 
> Patch 5: Make the EDID parser recognize the "DFP1.x compatible TMDS"
> bit by which DVI sinks can declare they support at least 8 bpc according
> to DFP spec. This one if applied would let me sleep so much better, as
> the common special display equipment for neuroscience research, which is
> all DVI based atm., sets that bit in its EDID 1.3.
> 
> Thanks,
> -mario
> 

-- 
Daniel Vetter
Software Engineer, Intel Corporation
http://blog.ffwll.ch