Re: no hw.acpi.video.lcd0 with graphics/drm-510-kmod

On 5/23/22 00:37, Emmanuel Vadot wrote:
> On Sun, 22 May 2022 09:08:12 -0700
> Pete Wright <pete@nomadlogic.org> wrote:
>
>> hello,
>> i have a lenovo P43s laptop running current.  i've noticed that since
>> graphics/drm-510-kmod became available hw.acpi.video.lcd0 ceases to
>> exist (which makes it impossible to adjust screen brightness).  i've
>> installed graphics/drm-54-kmod and things work as expected.  previously
>> i was running drm-devel-kmod without issues, so i think it's probably an
>> issue with the 5.10 driver?
>>
>> i can file a bug report for this (or just test out patches here if
>> that's easier), but wanted to see if anyone here had observed this on
>> other laptops first.
>>
>> cheers,
>> -pete
>>
>> -- 
>> Pete Wright
>> pete@nomadlogic.org
>> @nomadlogicLA
>>
>>
>   Not sure what's happening as this sysctl is exposed by acpi_video(4)
> and not related to drm.
>   But you shouldn't need this, backlight(8) should work everywhere once
> drm is loaded.

yea that's why i was confused, i investigated acpi_video changes and 
didn't see anything obvious.

before i started trying to bisect recent acpi changes i thought it would 
be a good idea to test the drm-54-kmod port, which restored that sysctl 
knob.  sounds like i should continue to try to bisect the acpi kernel 
changes under 5.10 and see what i can find though.

cheers,
-p


-- 
Pete Wright
pete@nomadlogic.org
@nomadlogicLA