Re: [ibm-acpi-devel] Got an unsupported brightness acpi

[Henrique de M. H. <hm...@hm...>]

On Thu, May 7, 2015, at 14:19, Henrique de Moraes Holschuh wrote:
> On Tue, Apr 21, 2015, at 16:04, Andrew Wienecke wrote:
>> This was working previously, was working during the netboot install,
>> is no longer working. Fixes online didn't. I'm going to try a few
>> more things, but this is about all the useful stuff I'm aware that I
>> should provide, let me know if you need more.
>>
>> [ 3.470352] thinkpad_acpi: ThinkPad ACPI Extras v0.25 [ 3.470360]
>> thinkpad_acpi: http://ibm-acpi.sf.net/ [ 3.470363] thinkpad_acpi:
>> ThinkPad BIOS GSET60WW (2.05 ), EC unknown [ 3.470366] thinkpad_acpi:
>> Lenovo ThinkPad X140e, model 20BLS00400 [ 3.476142] thinkpad_acpi:
>> Unsupported brightness interface, please contact
>> ibm...@li... [ 3.483092] thinkpad_acpi: radio
>> switch found; radios are enabled [ 3.483124] thinkpad_acpi: possible
>> tablet mode switch found; ThinkPad in laptop mode [ 3.483148]
>> thinkpad_acpi: This ThinkPad has standard ACPI backlight brightness
>> control, supported by the ACPI video driver [ 3.483151]
>> thinkpad_acpi: Disabling thinkpad-acpi brightness events by
>> default...
>
> Well, brightness control for the X140e goes through the GPU drivers,
> and not thinkpad-acpi. Check the ATI Radeon driver stack, etc.
>
> IOW, the issue is unlikely (but not impossible) to be related to
> thinkpad-acpi.

I replied too soon. This is either an Ubuntu or Debian with a 3.16
kernel, correct? Apparently there is some sort of change (and a
regression) in the 3.16-ckt longterm kernel series which both distros
use for their kernels.

It is still very weird that it caused an user-visible change in
brightness handling, but I need to know what changed in that kernel to
understand what is happening.

--
"One disk to rule them all, One disk to find them. One disk to bring
them all and in the darkness grind them. In the Land of Redmond where
the shadows lie." -- The Silicon Valley Tarot Henrique Holschuh