Created attachment 32952 [details]
dmesg

Created attachment 32955 [details]
xorg.log

Sounds like an ACPI bug, Yakui please reassign or close as necessary.

any updates ?

(In reply to comment #4)
> any updates ?
> 
Sorry for the late response.

Can you confirm whether the backlight can be adjusted by using the following interface?
   > echo xx >/sys/class/backlight/acpi_video0/brightness


Will you please also attach the output of acpidump on your box? The acpidump can be obtained by using pm_tools(20071116), which can be downloaded from:
    >http://www.lesswatts.org/projects/acpi/utilities.php

Thanks.

Created attachment 33914 [details]
acpidump of NV59

(In reply to comment #5)
> (In reply to comment #4)
> > any updates ?
> > 
> Sorry for the late response.
> 
> Can you confirm whether the backlight can be adjusted by using the following
> interface?
>    > echo xx >/sys/class/backlight/acpi_video0/brightness
> 

This does not work. Brightness always stays to maximum
> 
> Will you please also attach the output of acpidump on your box? The acpidump
> can be obtained by using pm_tools(20071116), which can be downloaded from:
>     >http://www.lesswatts.org/projects/acpi/utilities.php
> 
> Thanks.
> 
I have attached the output to the bug


Thanks.

(In reply to comment #6)
> Created an attachment (id=33914) [details]
> acpidump of NV59
> 
thanks for the so quick response.

After checking the ACPIdump on this box it seems that the brightness issue is related with the BIOS. The brightness is adjusted by using "_BCM" object, which is defined as the following:
   >  Method (_BCM, 1, NotSerialized)
        {
        If (^^^LPCB.EC0.BNCM)
            {
                If (^^^LPCB.EC0.ACST)
                {
                    Store (Local1, ^^^LPCB.EC0.BNAC)
                }
                Else
                {
                    Store (Local1, ^^^LPCB.EC0.BNDC)
                }
            }
            Else
            {
                Store (Local1, ^^^LPCB.EC0.BNAC)
            }
        }

     The expected brightness value is written to the internal register of Embedded controller(EC). But unfortunately the brightness can't be adjusted by EC.

From me it seems that this is a BIOS bug rather the graphics bug.

thanks.
    Yakui

mark as notourbug per last comment from yakui