Bug 11478

Problem Description:
Brightness function keys work before Linux is loaded. For example, it works in
GRUB. 

However when I boot with the kernel option noacpi or acpi=ht, The function keys work perfectly. 

Will you please attach the output of dmesg, acpidump?
Thanks.

with ACPI enabled, with ACPI video driver loaded,
can you change the brightness via the sysfs backlight interface (/sys/class/backlight/acpi_video0/...) ?
can you change the brightness via the procfs I/F (/proc/acpi/video/xxx/yyy/brightness) ?
If yes, please kill acpid and run "cat /proc/acpi/event". what can you see when pressing the hotkey?
If no, please attach the acpidump output.

Created attachment 17589 [details]
dmesg output

I really don't know much about the operations you mention here. I however run 'cat /proc/acpi/event' and i had a 'no such file or directory found' error message. I however killed it using gnome-system-monitor but it the brightness function keys still do not work. I am attaching the acpidump.


(In reply to comment #3)
> with ACPI enabled, with ACPI video driver loaded,
> can you change the brightness via the sysfs backlight interface
> (/sys/class/backlight/acpi_video0/...) ?
> can you change the brightness via the procfs I/F
> (/proc/acpi/video/xxx/yyy/brightness) ?
> If yes, please kill acpid and run "cat /proc/acpi/event". what can you see
> when
> pressing the hotkey?
> If no, please attach the acpidump output.
> 

Created attachment 17590 [details]
acpidump

please check the kernel config file and make sure

(In reply to comment #5)
> I really don't know much about the operations you mention here. I however run
> 'cat /proc/acpi/event' and i had a 'no such file or directory found' error
> message.
Please attach the kernel config file here.
Please make sure CONFIG_ACPI_PROC_EVENT is set in your kernel config.

> I however killed it using gnome-system-monitor but it the brightness
> function keys still do not work. I am attaching the acpidump.
> 
> 
> (In reply to comment #3)
> > with ACPI enabled, with ACPI video driver loaded,
> > can you change the brightness via the sysfs backlight interface
> > (/sys/class/backlight/acpi_video0/...) ?
please run the following commands:
echo 0 > /sys/class/backlight/acpi_video0/brightness;
echo 7 > /sys/class/backlight/acpi_video0/brightness;
is the brightness acutally changed?

I'm still trying to find the kernel config but it seems i have to download the sources first.

(In reply to comment #7)
> please check the kernel config file and make sure
> 
> (In reply to comment #5)
> > I really don't know much about the operations you mention here. I however
> run
> > 'cat /proc/acpi/event' and i had a 'no such file or directory found' error
> > message.
> Please attach the kernel config file here.
> Please make sure CONFIG_ACPI_PROC_EVENT is set in your kernel config.
> 
> > I however killed it using gnome-system-monitor but it the brightness
> > function keys still do not work. I am attaching the acpidump.
> > 
> > 
> > (In reply to comment #3)
> > > with ACPI enabled, with ACPI video driver loaded,
> > > can you change the brightness via the sysfs backlight interface
> > > (/sys/class/backlight/acpi_video0/...) ?
> please run the following commands:
> echo 0 > /sys/class/backlight/acpi_video0/brightness;
> echo 7 > /sys/class/backlight/acpi_video0/brightness;
> is the brightness acutally changed?

running the commands still returned a file not found error.

(In reply to comment #8)
> I'm still trying to find the kernel config but it seems i have to download
> the
> sources first.
> 
> (In reply to comment #7)
> > please check the kernel config file and make sure
> > 
> > (In reply to comment #5)
> > > I really don't know much about the operations you mention here. I however
> run
> > > 'cat /proc/acpi/event' and i had a 'no such file or directory found'
> error
> > > message.
> > Please attach the kernel config file here.
> > Please make sure CONFIG_ACPI_PROC_EVENT is set in your kernel config.
> > 
> > > I however killed it using gnome-system-monitor but it the brightness
> > > function keys still do not work. I am attaching the acpidump.
> > > 
> > > 
> > > (In reply to comment #3)
> > > > with ACPI enabled, with ACPI video driver loaded,
> > > > can you change the brightness via the sysfs backlight interface
> > > > (/sys/class/backlight/acpi_video0/...) ?
> > please run the following commands:
> > echo 0 > /sys/class/backlight/acpi_video0/brightness;
> > echo 7 > /sys/class/backlight/acpi_video0/brightness;
> > is the brightness acutally changed?
> 
> running the commands still returned a file not found error.
> 
Please make sure the CONFIG_ACPI_VIDEO is m/y, please make sure the acpi video driver is loaded if it's not compiled in.
will you please attach the kernel config file here?

i am having trouble finding the kernel configuration even after installing the kernel sources.

well. please attach the result of "ls /sys/class/backlight" and "ls /proc/acpi/".

Created attachment 17857 [details]
output of 'ls /proc/acpi/

(In reply to comment #11)
> well. please attach the result of "ls /sys/class/backlight" and "ls
> /proc/acpi/".
> 

output of 'ls /sys/class/backlight' is empty

Hmm, _BQC method is missed in this BIOS.

could you please try any later kernel release please, say 2.6.26?
you should see something under /sys/class/backlight/ then.
please verify if this I/F can actually change the backlight.

I am running 2.6.27-3 and I am able to adjust the backlight. 

'/sys/class/backlight/' shows 'acpi_video0'

hah, seems that problem is fixed in the latest kernel.
Close this bug.