APPLIED[G]: [PATCH 0/1][SRU][F/OEM-5.6/Groovy] Fix acpi backlight issue on some thinkpads

[Seth Forshee]

On Tue, Aug 18, 2020 at 05:49:18AM -0400, Aaron Ma wrote:
> BugLink: https://bugs.launchpad.net/bugs/1892010
> 
> [Impact]
> On some ThinkPads, the BIOS reported invalid acpi backlight implement .
> Then backlight can't be changed because OS use acpi backlight by
> default.
> 
> [Fix]
> Check acpi backlight mode, disable it if invalid.
> 
> [Test Case]
> Verified on 3 models of thinkpad include Intel/NV/AMD GPU with positive
> results.
> 
> [Regression Potential]
> Low
> Most ThinkPads now use native backlight control by default.
> Check the false acpi mode correctly.

Applied to groovy/master-next, thanks!