Controlling backlight on thinkpad x60

Controlling backlight on thinkpad x60

[Pavel Machek]

Hi!

Some time ago, FN-Home/End just adjusted the brightness, and
/proc/acpi/ibm contained backlight control.

In 2.6.27-rc5, /proc/acpi/ibm does not contain backlight control and
/sys/class/backlight is empty...

(I do have CONFIG_ACPI_VIDEO disabled, it killed my machine last time
I enabled it, is it mandatory now?)
									Pavel
-- 
(english) http://www.livejournal.com/~pavelmachek
(cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html

Re: Controlling backlight on thinkpad x60

[Matthew Garrett]

On Mon, Sep 08, 2008 at 05:10:58PM +0200, Pavel Machek wrote:

> (I do have CONFIG_ACPI_VIDEO disabled, it killed my machine last time
> I enabled it, is it mandatory now?)

On Thinkpads with ACPI video support, yes.

-- 
Matthew Garrett | mjg59@srcf.ucam.org

[regression] Re: Controlling backlight on thinkpad x60

[Pavel Machek]

On Mon 2008-09-08 16:54:58, Matthew Garrett wrote:
> On Mon, Sep 08, 2008 at 05:10:58PM +0200, Pavel Machek wrote:
> 
> > (I do have CONFIG_ACPI_VIDEO disabled, it killed my machine last time
> > I enabled it, is it mandatory now?)
> 
> On Thinkpads with ACPI video support, yes.

That's bad then, because ACPI video support does not work here. I can
boot, and even Fn-home/end works, but it breaks with X.

In old versions, it resulted on black screen after LID close in X.

In 2.6.27-rc5, screen goes black as soon as X are started.

(In old versions, I could use ibm-acpi, and fn-home/end worked even
without CONFIG_ACPI_VIDEO...)

									Pavel
-- 
(english) http://www.livejournal.com/~pavelmachek
(cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html

Re: [regression] Re: Controlling backlight on thinkpad x60

[Pavel Machek]

On Tue 2008-09-09 17:28:59, Pavel Machek wrote:
> On Mon 2008-09-08 16:54:58, Matthew Garrett wrote:
> > On Mon, Sep 08, 2008 at 05:10:58PM +0200, Pavel Machek wrote:
> > 
> > > (I do have CONFIG_ACPI_VIDEO disabled, it killed my machine last time
> > > I enabled it, is it mandatory now?)
> > 
> > On Thinkpads with ACPI video support, yes.
> 
> That's bad then, because ACPI video support does not work here. I can
> boot, and even Fn-home/end works, but it breaks with X.
> 
> In old versions, it resulted on black screen after LID close in X.
> 
> In 2.6.27-rc5, screen goes black as soon as X are started.

Hmm, I have updated my X server, and it now works with
ACPI_VIDEO... which means that this is probably not affecting huge
number of people.

Hmm... something is still funny. I have 

root@amd:/sys/class/backlight/acpi_video0# echo 1 > brightness
root@amd:/sys/class/backlight/acpi_video0# echo 0 > brightness
root@amd:/sys/class/backlight/acpi_video0# cd ../acpi_video1/
root@amd:/sys/class/backlight/acpi_video1# echo 0 > brightness
root@amd:/sys/class/backlight/acpi_video1# echo 7 > brightness
root@amd:/sys/class/backlight/acpi_video1# echo 0 > brightness


...and both acpi_video0 *and* acpi_video1 works... strange.
									Pavel
-- 
(english) http://www.livejournal.com/~pavelmachek
(cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html

Re: [regression] Re: Controlling backlight on thinkpad x60

[Matthew Garrett]

On Tue, Sep 09, 2008 at 05:29:00PM +0200, Pavel Machek wrote:
> That's bad then, because ACPI video support does not work here. I can
> boot, and even Fn-home/end works, but it breaks with X.
> 
> In old versions, it resulted on black screen after LID close in X.

Yeah, X did retarded things in response to video events. That's been 
fixed for ages.

> In 2.6.27-rc5, screen goes black as soon as X are started.

That sounds bizarre, and I can't reproduce it here.

-- 
Matthew Garrett | mjg59@srcf.ucam.org

Re: [regression] Re: Controlling backlight on thinkpad x60

[Pavel Machek]

On Tue 2008-09-09 17:42:54, Matthew Garrett wrote:
> On Tue, Sep 09, 2008 at 05:29:00PM +0200, Pavel Machek wrote:
> > That's bad then, because ACPI video support does not work here. I can
> > boot, and even Fn-home/end works, but it breaks with X.
> > 
> > In old versions, it resulted on black screen after LID close in X.
> 
> Yeah, X did retarded things in response to video events. That's been 
> fixed for ages.
> 
> > In 2.6.27-rc5, screen goes black as soon as X are started.
> 
> That sounds bizarre, and I can't reproduce it here.

It was same old X. New X fix that. But I still have two backlight devices...

									Pavel
-- 
(english) http://www.livejournal.com/~pavelmachek
(cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html

Re: [regression] Re: Controlling backlight on thinkpad x60

[Matthew Garrett]

On Tue, Sep 09, 2008 at 06:55:58PM +0200, Pavel Machek wrote:

> It was same old X. New X fix that. But I still have two backlight devices...

Should be fixed in .28. Sorry about that, confusion over which DRM 
branches were getting merged meant it missed .27.

-- 
Matthew Garrett | mjg59@srcf.ucam.org