Brightness control help

rbh · 2020-12-23 10:05:36

ohnonot wrote:

So, since manually echoing values to a file works, the question is why doesn't xfce4-power-manager.

I do not think horo has said that works, neither if Fn keys works in BL live iso. If it wirks in live session, then next step I think would be to blacklist toshiba_acpi.

rbh · 2020-12-23 10:35:25

horo wrote:

I posted an update where I found I could control brightness as root by manipulating apci_video0/brightness

Something happened to that post, it can not be found.
So, you are not working in directory /sys/class/backlight/intel_backlight? what other files do you have there? Also an actual_brightness? They are not modified by pressing Fn-key?

From my understanding I can change permissions and and key bindings to enact a script that would let my Fn keys alter this file, but

You can do what you want on your machine, but is it wise to change file persission on system files? I think not...

I would rather figure out why intel_backlight isn't doing what it should since ALL the applications that I have effect this value.

You still have both "Toshiba Laptop ACPI Extras Driver" and intel_backlight? Maybe you should decide to use only one?

I still think it is a good idea for you to boot into live session and see it Fn-keys work there and if so investige difference between your install and live session.

Last edited by rbh (2020-12-23 10:35:53)

rbh · 2020-12-23 10:46:56

Use intel_backlight instead of acpi_backlight0?

rbh · 2020-12-23 10:53:44

Arch Wiki on Backlight
https://wiki.archlinux.org/index.php/Ba … ne_options

horo · 2020-12-24 17:32:03

Alright , I dug up the live USB used to install Lithium and here is what I learned-
1. The brightness set by echo X > /sys/class/backlight/acpi_video0/brightness persists even when booting to the live USB, so it's being saved somewhere on the motherboard
2. Live USB Lithium acts the same as installed Lithium. Fn keys register and manipulate the intel_backlight/brightness variable, but this does not effect the screen brightness, only acpi_video0/brightness does
3.Passing kernel parameters acpi_backlight=vendor or acpi_backlight=none remove the /sys/class/backlight/acpi_video0 directories on reboot, but the brightness level stays at what ever level it was set at previously.
Fn Keys, xfce4-power-manager slider, xbacklight all manipulate intel_backlight/brightness without effecting the screen.
4. i have confirmed by running inxi -G that I only have one graphics gpu, since several examples listed had multiple gpus that conflicted causing the problem

I have not blacklisted toshiba_acpi or made an xorg profile yet. I'll try the blacklisting when time permits, but ya know, holidays. I feel like I do not know enough for seting an xorg profile.

ohnonot · 2020-12-24 21:14:37

horo wrote:

2. Live USB Lithium acts the same as installed Lithium. Fn keys register and manipulate the intel_backlight/brightness variable, but this does not effect the screen brightness, only acpi_video0/brightness does

At this point I'd just override those keys' behavior in openbox' rc.xml.
Do you need help with that?

#21 2020-12-23 10:05:36

Re: Brightness control help

#22 2020-12-23 10:35:25

Re: Brightness control help

#23 2020-12-23 10:46:56

Re: Brightness control help

#24 2020-12-23 10:53:44

Re: Brightness control help

#25 2020-12-24 17:32:03

Re: Brightness control help

#26 2020-12-24 21:14:37

Re: Brightness control help

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