00:00.0 Host bridge: Intel Corporation Mobile PM965/GM965/GL960 Memory Controller Hub (rev 0c)
00:02.0 VGA compatible controller: Intel Corporation Mobile GM965/GL960 Integrated Graphics Controller (rev 0c)
00:02.1 Display controller: Intel Corporation Mobile GM965/GL960 Integrated Graphics Controller (rev 0c)

probably not video driver issue. 
maybe acpi related. Rui/Hong, any comments?

Please
make sure CONFIG_ACPI_DEBUG is set.
echo 0x44 > /sys/module/acpi/parameters/debug_layer
echo 0x8800001f > /sys/module/acpi/parameters/debug_level
press the hotkey and attach the dmesg output.

(In reply to comment #3)
> Please
> make sure CONFIG_ACPI_DEBUG is set.
> echo 0x44 > /sys/module/acpi/parameters/debug_layer
> echo 0x8800001f > /sys/module/acpi/parameters/debug_level
> press the hotkey and attach the dmesg output.
> 

set this both commands the CONFIG_ACPI_DEBUG? Or I have to recompile my kernel?

Check with 

  zcat /proc/config.gz |grep CONFIG_ACPI_DEBUG

(In reply to comment #4)
> (In reply to comment #3)
> > Please
> > make sure CONFIG_ACPI_DEBUG is set.
You need to rebuild the kernel if it is cleared.

> > echo 0x44 > /sys/module/acpi/parameters/debug_layer
> > echo 0x8800001f > /sys/module/acpi/parameters/debug_level
try these commands in the kernel with CONFIG_ACPI_DEBUG=y.

Yeah, this isn't an X driver bug, it's probably a kernel or desktop configuration issue (some kernels send keyboard events for the hotkeys and your desktop has to be configured to handle them).  Rui, if you're not the right owner can you assign to the thinkpad guys maybe?

Please attach the acpidump output as well.
You can use the latest pmtools here:
http://www.kernel.org/pub/linux/kernel/people/lenb/acpi/utils/

Created attachment 16386 [details]
acpidump

Created attachment 16387 [details]
dmesg log

zcat /proc/config.gz | grep CONFIG_ACPI_DEBUG
CONFIG_ACPI_DEBUG=y
# CONFIG_ACPI_DEBUG_FUNC_TRACE is not set

I have attached dmesg and acpidump.

acpi_listen means:
^@video LCD0 00000086 00000000
^@video LCD0 00000087 00000000

There should be two acpi_videoX directory under /sys/class/backlight after loading the ACPI video driver. One should work and another one may not.
could you please try the patch and do the same test at
http://bugzilla.kernel.org/show_bug.cgi?id=9995#c13

sorry, the patch: http://bugzilla.kernel.org/show_bug.cgi?id=9995#c13 doesn't help.

(In reply to comment #13)
> sorry, the patch: http://bugzilla.kernel.org/show_bug.cgi?id=9995#c13 doesn't
> help.
> 
Maybe I'm not clear, the patch won't change anything, it just create a symbol link from the backlight sys class to the ACPI device node, and it may help us find out which sysfs I/F actually works.
Please refer to http://bugzilla.kernel.org/show_bug.cgi?id=9995#c16

Created attachment 16730 [details] [review]
patch: show which device the hotkey event is sent to

Please apply this patch, and attach the dmesg output after pressing the brightness hotkey for several times.

Created attachment 17210 [details]
dmesg output

I have attached the new dmesg output.

btw: acpi_listen means now:
ibm/hotkey HKEY 00000080 00001011
video LCD0 00000087 00000000
^@ibm/hotkey HKEY 00000080 00001010
^@video LCD0 00000086 00000000

Since Kent asked me about the severity/priority. I don't think this is a major issue.

this is a laptop with IGD OpRegion BIOS.
please try the latest kernel  - in which IGD OpRegion patches are shipped - to see if it helps.

Stephan, did you try OpenSuSE 11.1 Beta 4, which uses 2.6.27 kernel?

On Tue, 2008-11-11 at 15:20 +0800, bugzilla-daemon@freedesktop.org
wrote:
> http://bugs.freedesktop.org/show_bug.cgi?id=15773
> 
> 
> 
> 
> 
> --- Comment #20 from Kent Liu <kent.liu@intel.com>  2008-11-10 23:20:33 PST ---
> Stephan, did you try OpenSuSE 11.1 Beta 4, which uses 2.6.27 kernel?
> 
I'm afraid 2.6.27 doesn't help as the IGD patches went into 2.6.28-rcX.
better to try a vanilla kernel. :)

thanks,
rui

2.6.28-RCx kernel has been pushed into kernel. However for 2.6.27 kernel of Novell, it has no gem source code. Even we got this, it still can not help anything?

(In reply to comment #22)
> 2.6.28-RCx kernel has been pushed into kernel. However for 2.6.27 kernel of
> Novell, it has no gem source code. Even we got this, it still can not help
> anything?
> 

Sorry it is gem which has been pushed into kernel 2.6.28-RCx. For 2.6.27, there is no gem source code.

What Rui said in comment #19(21) is right. From the acpidump it seems that this is  a laptop with IGD Opregion . 
   After the hotkey is pressed, the notification event is sent to the corresponding ACPI video device. And then brightness interface is called to change the brightness. Unfortunately the brightness can't be changed by evaluating the _BCM object if the IGD opregion patch is not shipped.
   
   
    

So it's a kernel issue. Supposed to be fixed with openSUSE 11.2. Assuming that we'll pick up 2.6.28 or later.

mark fixed then.