Will you please try to load the fujitsu-laptop driver and see whether the issue still exists?
   Will you please also attach the output of acpidump?
   thanks.

(In reply to comment #0)
> I have two problems:
> 
> 1. I cannot control a backlight through keys: Fn+F8 (brightness down) and
> Fn+F9
> (brightness up). No ACPI events are occured by pressing these keys. If ACPI
> is
> off then i can control it.
> 
this doesn't sounds good.
are there any i8042 interrupts when you pressing the hotkeys?
you can test like this, remote login and get the content of /proc/interrupts bother before and after pressing the hotkeys.

> 2. My system doesn't have the backlight interface under /sys/class/backlight
> and /proc/acpi/video. Module 'video' is loaded.

                        Method (_BCL, 0, NotSerialized)
                        {
                            Return (Package (0x0A)
                            {
                                0x07,
                                0x00,
                                0x00,
                                0x01,
                                0x02,
                                0x03,
                                0x04,
                                0x05,
                                0x06,
                                0x07
                            })
                        }

Well, the backlight control method is buggy.
But this should be fixed by the new ACPI video fixes.
please do the test in comment #91 bug #12249, without step 1 and step 6, and see if it helps

(In reply to comment #1)
> Will you please try to load the fujitsu-laptop driver and see whether the
> issue
> still exists?
>    Will you please also attach the output of acpidump?
>    thanks.

I loaded the fujitsu-laptop driver and the issue still exists. It created the backlight interface under /sys/class/backlight but 'echo 5 > /sys/class/backlight/fujitsu-laptop/brightness' doesn't do anything.

/sys/class/backlight/fujitsu-laptop/uevent: 
/sys/class/backlight/fujitsu-laptop/bl_power: 0
/sys/class/backlight/fujitsu-laptop/brightness: 5
/sys/class/backlight/fujitsu-laptop/actual_brightness: 0
/sys/class/backlight/fujitsu-laptop/max_brightness: -1
/sys/class/backlight/fujitsu-laptop/power/wakeup:

Output of acpidump is in the first post.

Created attachment 20851 [details]
Content of /proc/interrupts before pressing the hotkeys

Created attachment 20852 [details]
Content of /proc/interrupts after pressing the hotkeys

(In reply to comment #2)
> > 2. My system doesn't have the backlight interface under
> /sys/class/backlight
> > and /proc/acpi/video. Module 'video' is loaded.
> 
>                         Method (_BCL, 0, NotSerialized)
>                         {
>                             Return (Package (0x0A)
>                             {
>                                 0x07,
>                                 0x00,
>                                 0x00,
>                                 0x01,
>                                 0x02,
>                                 0x03,
>                                 0x04,
>                                 0x05,
>                                 0x06,
>                                 0x07
>                             })
>                         }
> 
> Well, the backlight control method is buggy.
> But this should be fixed by the new ACPI video fixes.
> please do the test in comment #91 bug #12249, without step 1 and step 6, and
> see if it helps

I applied all 8 patches but it doesn't help.

_BQC method is not implemented in this BIOS, and the _BCL method provides indexed values.
enabling the ACPI video extension support on this laptop seems to be difficult, sigh...
I'll have a try once the previous 8 patches are upstream.

please attach the lspci output

Created attachment 20857 [details]
Output of lspci

Hi, Piotr
    Will you please try the 2.6.28-xx kernel(for example: 2.6.28.3) and see whether there exists the backlight interface under the /sys/class/backlight/ ?
    It will be great if you can add the boot option of "acpi.debug_layer=0x10000000 acpi.debug_level=0x01f initcall_debug" on the 2.6.28-xx kernel and attach the output of dmesg. Of course the CONFIG_ACPI_DEBUG should be set in kernel configuration.

    if there exists the backlight interface under /sys/class/backlight, please confirm whether the backlight can be changed by using it.
    Thanks.

Created attachment 20860 [details]
Output of dmesg of kernel 2.6.28.7 with acpi debug and parameters: acpi.debug_layer=0x10000000 acpi.debug_level=0x01f initcall_debug

Also there are no backlight interface under /sys/class/backlight and /proc/acpi/video.

Hi, Piotr
    From the acpidump we know that there is no _DOS object, which is required for brightness control. In such case we have no generic ACPI backlight I/F. 
    At the same time there is no ACPI device for fujitsu driver, which means that the backlight I/F registered by fujitsu driver is meaningless. Of course the brightness can't be controlled by it.
   
    When the system is booted with ACPI disabled, the brightness can be controlled by hotkey. Maybe this is handled in SMI mode. But this is different with ACPI.

    From the above analysis it seems that this issue is related with BIOS. And this had better be fixed by BIOS upgrading.
    Thanks.

Close this bug as this is not an ACPI problem.
As the backlight control usually needs some platform specific methods, I think you'd better file a bug report at freedesktop against the nvidia category to see if they have any good ideas..

As a workaround I wrote the driver which invoked _BCM method and created the backlight interface.

But the problem with the hotkeys still persists (no keycodes of keys).

Thanks for your help anyway.