[SOLVED] Systemd forcing laptop brightness down to zero.

Question

Can somebody please, pretty please, explain to me how I can tell systemd to STOP turning off my laptop brightness half-way during boot?
Started Load/Save Screen Backlight Brightness of acpi_video0.
Turns brightness down to zero. According to the man page:
[email protected] is a service that restores the display backlight brightness at early-boot and saves it at shutdown. On disk, the backlight brightness is stored in /var/lib/backlight/.
On my Arch it is actually in /var/lib/systemd/backlight/acpi0. I tried modifying the value to anything between 1 and 100 but it the file is reset to 0 every boot, maybe this is normal.
I also tried to disable the damn systemd-backlight service but it re-enables itself every boot too.
Please can somebody help me, I'm pulling my hair out. I have tried various kernel parameters and acpi_backlight=vendor works but forces brightness to 100% and I can't change it. (unless of course if I force /sys/class/... which is not a solution)
Last edited by beanaroo (2013-10-12 07:30:49)

Answer 1

It definitely isn't normal for it to keep going to 0. Mine currently has the value 12 in it. (My file is /var/lib/systemd/backlight/acpi_video0.) I'm not sure if it makes a difference that I have laptop-mode-tools managing the backlight, though. But I don't see it go to 0 at any point during boot.
That is, unless something somewhere is configuring it this way, this sounds like a bug and the solution you're using a work around. Not suggesting you shouldn't use it, of course, but maybe worth reporting, too?
Last edited by cfr (2013-10-16 02:25:51)