nwinkler
30th January 2007, 11:26 AM
Another ACPI related problem: I have a new LG W1 laptop, in the pre-installed Windows XP I can change display brightness by using Fn+Up and Fn+Down. In FC6, this doesn't work. Here's a couple of things I found out:
Using Fn+Up and Fn+Down works when the computer boots, up to the point when Grub starts Linux, so it looks like support for this is built in at a very low level. Something in Fedora disables this behavior.
I can change display brightness by writing to /proc/acpi/video/EGFX/LCD0/brightness (levels 1-9). Doing a "cat" on this file reports the current settings.
Looking at /var/log/messages, I see the output "video device notify" whenever I press either Fn+Up or Fn+Down. Does anybody know where this comes from?
Pressing Fn+Up causes an event which can be seen in /var/log/acpid: "video 86" or something like this. Fn+Down doesn't generate such an event.
Does anybody know how to trap the ACPI events generated by Fn+Up and Fn+Down so I can attach an acpi action to increase or decrease the screen brightness?
Thanks,
Nils
Using Fn+Up and Fn+Down works when the computer boots, up to the point when Grub starts Linux, so it looks like support for this is built in at a very low level. Something in Fedora disables this behavior.
I can change display brightness by writing to /proc/acpi/video/EGFX/LCD0/brightness (levels 1-9). Doing a "cat" on this file reports the current settings.
Looking at /var/log/messages, I see the output "video device notify" whenever I press either Fn+Up or Fn+Down. Does anybody know where this comes from?
Pressing Fn+Up causes an event which can be seen in /var/log/acpid: "video 86" or something like this. Fn+Down doesn't generate such an event.
Does anybody know how to trap the ACPI events generated by Fn+Up and Fn+Down so I can attach an acpi action to increase or decrease the screen brightness?
Thanks,
Nils
