[ltp] X200 brightness keys behavior weirdness - down is up, up is down (sometimes)

[n0rdik0]

Henrique de Moraes Holschuh-2 wrote:
> 
> On Wed, 29 Oct 2008, John Li wrote:
>> On Tue, Oct 28, 2008 at 10:18:33AM -0200, Henrique de Moraes Holschuh
>> wrote:
>> > On Mon, 27 Oct 2008, John Li wrote:
>> > > [    6.917378] thinkpad_acpi: This ThinkPad has standard ACPI
>> backlight brightness control, supported by the ACPI video driver
>> > > [    6.917449] thinkpad_acpi: Disabling thinkpad-acpi brightness
>> events by default...
>> > > [    6.925138] thinkpad_acpi: Lenovo BIOS switched to ACPI backlight
>> control mode
>> > > [    6.925138] thinkpad_acpi: standard ACPI backlight interface
>> available, not loading native one...
>> > 
>> > It is doing the right thing.  You now need a very new X.org, a very new
>> > kernel (for a very new ACPI video, and various EC interrupt fixes)...
>> 
>> How new? I tend stick with the Debian kernels because I've had bad
>> luck with compiling my own kernels (I unknowingly disable required
>> options or modules and not being able to boot X, or something).
> 
> Much newer than that :(  2.6.28-rc with X.org from git.  It is likely that
> you'd be much better off waiting for two or three months on this one.
> 
> For workarounds, you can *try* to not load ACPI video, and force
> thinkpad-acpi to make the brightness control interface available (in CMOS
> mode if it doesn't detect that automatically, which I believe it should).
> Use the thinkpad-acpi from ibm-acpi.sf.net, otherwise you WILL get very
> annoying delays on brightness key processing.
> 
> The X200 is engineered to work with ACPI video, so you will likely have to
> enable the brightness keys in thinkpad-acpi as well, and either get HAL or
> gnome or an acpid script to handle those.   This is exactly the WRONG
> thing
> to do on most thinkpads, but it is the way to deal with the X61, X300 and
> X200 *WHEN* working around the lack of Intel opRegion X.org support for
> brightness change in a distro.
> 
> It *will* break horribly when X.org and the kernel start doing opRegion
> control, BTW.
> 
>> And I've never tried building X.org before.
> 
> For this case, I think you better not try.  You'd be switching from
> somewhat
> stable DRM to GEM-based bleeding-edge direct rendering which is fairly
> likely to have annoying bugs both in X.org AND the kernel.
> 
>> I think they're okay. Though, the fan revs up much more often than
>> under Vista, and it doesn't seem to slow down again, but that's
>> another issue :).
> 
> Can you try to identify the situation when the thinkpad issues those
> events?
> That way, we could add support for them... might be a powersave hint or
> somesuch, Lenovo has been adding some of these lately...
> 
>> > > just work. Based on the dmesg output above, I assume they're handled
>> > > by the standard ACPI backlight interface, and not thinkpad_acpi.
>> > 
>> > Correct.  And ACPI should just be telling the X.org driver what to do,
>> but
>> > X.org had a LOT of HIDEOUS bugs on that area (and ACPI video took some
>> time
>> > to be cleaned up as well, and had its bad share of bugs).
>> 
>> Good to know it's getting better :).
> 
> Oh, it is.  For Intel and ATi anyway.  Everything else seems to be eigher
> ignored (maybe they don't need extra support? who knows) or in the dark
> ages.
> 
> -- 
>   "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
> -- 
> The linux-thinkpad mailing list home page is at:
> http://mailman.linux-thinkpad.org/mailman/listinfo/linux-thinkpad
> 
> 
Just FYI, I've had this *exact same* issue and "workarounded" it by
blacklisting the video module, applying the all_buttons hotkey mask and
processing the acpi events in /etc/acpi/handler.sh, as well as the suspend,
hibernate and bluetooth off hotkeys. The acpi events are generated correctly
so the is no one-key-lag problem. I'm using the 2.6.27 kernel and it seem to
work pretty well so far.
If somebody wants the scripts, fell free to ask and I'll post them.
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