[Intel-gfx] Legacy backlight control with KMS and BACKLIGHT property

[Mike Lothian]

2009/8/19 Jesse Barnes <jbarnes at virtuousgeek.org>:
> On Wed, 19 Aug 2009 01:25:57 +0100
> Mike Lothian <mike at fireburn.co.uk> wrote:
>
>> 2009/8/18 Jesse Barnes <jbarnes at virtuousgeek.org>:
>> > On Mon, 17 Aug 2009 01:41:03 +0100
>> > Mike Lothian <mike at fireburn.co.uk> wrote:
>> >> You are an absolute STAR Greg!!!
>> >>
>> >> Finally I have brightness control for this laptop on Linux
>> >>
>> >> I needed to set the DMI names to "R510/P510" and the pci device to
>> >> 0x2a42 but apart from that it works!!!
>> >>
>> >> Now I just have to get the keys working :D
>> >
>> > Any chance I could get you to test this patch out?  It should add an
>> > "i915-backlight" interface to sysfs instead, but hopefully will work
>> > similarly otherwise...
>> >
>> > Thanks,
>> > --
>> > Jesse Barnes, Intel Open Source Technology Center
>> >
>>
>> Sorry I tried this on the latest tip from Linus and it has no effect
>>
>> It might be because I do have acpi video (with or without the patch)
>> it just doesn't do anything when I change the values
>>
>> Let me know if there are any logs you need, parameters I need to pass
>> or other patches to try
>
> Oh, you have a GM45, that should have OpRegion support afaik...  Just
> for fun though, can you send me your VBIOS image?
>
> # cd /sys/devices/pci0000\:00/0000\:00\:02.0/
> # echo 1 > rom
> # cat rom > /tmp/rom.bin
> # echo 0 > rom
>
> Thanks,
> --
> Jesse Barnes, Intel Open Source Technology Center
>

That doesn't seem to work

tau 0000:00:02.0 #  echo 1 > rom
bash: rom: No such file or directory