On Thu, Apr 26, 2018 at 03:53:02PM +0300, Mika Westerberg wrote:
> Hi,
>
> It seems that commit f5a26acf0162 ("pinctrl: intel: Initialize GPIO
> properly when used through irqchip") can cause problems on some Skylake
> systems with Sunrisepoint PCH-H. Namely on certain systems it may turn
> the backlight PWM pin from native mode to GPIO which makes the screen
> blank during boot.
>
> There is more information here:
>
> https://bugzilla.redhat.com/show_bug.cgi?id=1543769
>
> The actual reason is that GPIO numbering used in BIOS is using "Windows"
> numbers meaning that they don't match the hardware 1:1 and because of
> this a wrong pin (backlight PWM) is picked and switched to GPIO mode.
>
> There is a proper fix for this but since it has quite many dependencies
> on commits that cannot be considered stable material, I suggest we
> revert commit f5a26acf0162 from stable trees 4.9, 4.14 and 4.15 to
> prevent the backlight issue.
What is the "proper fix"? Is it in Linus's tree yet?
thanks,
greg k-h