Re: 2.6.25-rc1 regression - IBM ACPI backlight

[Henrique de Moraes Holschuh]

On Thu, 14 Feb 2008, Lukas Hejtmanek wrote:
> as of 2.6.25-rc1, there is no more /sys/class/backlight/acpi_video1 which
> controlled LVDS backlight on Lenovo ThinkPad T61. There is still acpi_video0
> which seems to have sane values but echo N > brightness has no effect at all.
> 
> thinkpad_acpi module reports that ACPI controlled backlight is present.

Please report this to linux-acpi @ vger . kernel . org...

It is likely caused by the stuff to locate and disable the unused video
device in the DSDT (apparently it got the wrong device?!).

However, BEFORE reporting to linux-acpi, please test it in single user mode
without X *ever* being loaded on that boot.  New X disables the BIOS
brightness changes that ACPI uses.

-- 
  "One disk to rule them all, One disk to find them. One disk to bring
  them all and in the darkness grind them. In the Land of Redmond
  where the shadows lie." -- The Silicon Valley Tarot
  Henrique Holschuh
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