[Bug 97883] [i915] intel_backlight does not function - Lenovo X1 Yoga OLED

[bugzilla-daemon at freedesktop.org]

https://bugs.freedesktop.org/show_bug.cgi?id=97883

--- Comment #25 from Jani Nikula <jani.nikula at intel.com> ---
(In reply to Niklas Kielblock from comment #19)
> The download above contains debug symbols, so I've done some cursory
> analysis. It communicates with the panel via eDP AUX (couldn't say if it's
> using I2C-over-AUX, though) through an interface exposed by the primary
> Intel graphics driver. References to gamma and voltages (ELVSS) indicate
> it's considerably more low-level.

The panel's DPCD indicates that it doesn't support the DP standard native aux
backlight control (see comment #7). It seems like some proprietary sauce.

> It's developed by Intel, not a third-party manufacturer; I have no insight
> into your organisation so forgive me if I'm wrong but I would imagine you
> can inquire about this internally.

Suffice it to say, it's not just tracking this down, it's also getting the
permission to open source something that the display vendor apparently deemed
best to do in their own proprietary way instead of following the DP specs.

-- 
You are receiving this mail because:
You are the assignee for the bug.
You are on the CC list for the bug.
You are the QA Contact for the bug.
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <https://lists.freedesktop.org/archives/intel-gfx-bugs/attachments/20180119/8d4b2f5e/attachment.html>