[Intel-gfx] [PATCH] drm/i915: inverted brightness quirk for HP 2000 Notebook

[Daniel Vetter]

On Wed, Aug 28, 2013 at 7:38 PM, Rodrigo Vivi <rodrigo.vivi at gmail.com> wrote:
> 01.org forum: https://01.org/linuxgraphics/node/199
>
> Slot:  00:02.0
> Class: VGA compatible controller [0300]
> Vendor:    Intel Corporation [8086]
> Device:    2nd Generation Core Processor Family Integrated Graphics Controller [0106]
> SVendor:   Hewlett-Packard Company [103c]
> SDevice:   Device [1854]
> Rev:       09
>
> Reported-by: Laurent Chardon <laurent.chardon at gmail.com>
> Cc: Jani Nikula <jani.nikula at intel.com>
> Signed-off-by: Rodrigo Vivi <rodrigo.vivi at gmail.com>

All the inverted brightness machines we've seen have been gen4 and
Acer/Packard Bell. I suspect there's something amiss in our backlight
handling and at least for current platforms I don't want to merge
quirks before we've reasonably proven that we really need them. Which
means someone should show that Windows has specific code for this HP
laptop first ...

One thing I remember is that there's a linearization table in the vbt
somewhere, maybe that does the trick. Or we simply race our driver
against something in the firmware and inverting the brightness here
cures that.
-Daniel
-- 
Daniel Vetter
Software Engineer, Intel Corporation
+41 (0) 79 365 57 48 - http://blog.ffwll.ch