DRM properties set by other compositors are not reset and mess with AQ

[UjinT34]

Some (all?) DRM properties keep their values after the compositor exits. Not all of such properties are reset when HL starts, some of those properties aren't even supported by AQ. This might result in a picture difference if HL is started after some other compositor. E.g. kwin HDR and CM settings affect HL's gamma and saturation:

1. start kwin
2. enable hdr and adjust some settings
3. exit kwin
4. start HL.
   HL renders in SDR mode with CM settings suitable for HDR mode which results in washed out colors.

Should be some generic way to reset everything. https://dri.freedesktop.org/docs/drm/gpu/drm-kms.html#c.drm_mode_config_reset?

[vaxerski]

Should be some generic way to reset everything

Yeah, I haven't found one yet. :P