Ubuntu
hal-info package

  1. Bug #415023
  2. Comment #98

Comment 98 for bug 415023

Revision history for this message
Martin Pitt (pitti) wrote : Re: [Bug 415023] Re: brightness is broken on MSI WIND U100

yze [2009-10-29 12:06 -0000]:
> @steve
> echo 4 > /proc/acpi/video/IGD/DOS
> bash: /proc/acpi/video/IGD/DOS: Permission denied

That needs superuser privileges. Please try

  echo 4 | sudo tee /proc/acpi/video/IGD/DOS

If that is too magical for you, you can also do

  $ sudo -i
  # echo 4 > /proc/acpi/video/IGD/DOS

> andrew@msiu:~$ sudo echo 4 > /proc/acpi/video/IGD/DOS

This doesn't work. This only runs "echo" as root (which is
unnecessary), the ">" (output redirection) is processed by the shell
(bash) which doesn't run as root.