Keyboard backlight

[lostintech]

I'm new to Mint having emigrated from Windows - so treat anything I say with caution.
I'm another one with a keyboard backlight issue.
cat /proc/bus/input/devices returns "AT Translated set 2 keyboard"
I'm running a vanilla install of Mint 21.3 with all updates installed. The package was 20220329.git681281e4-Oubuntu3.24 updated to 3.26
The backlit keyboard works fine in Windows where Fn + Z turns the backlight on and off.
In Mint: the backlight setting in BIOS is set to ON and the backlight comes on initially until Mint starts to load. At which point the backlight turns off and stays off. Fn + Z brings up an icon on screen with a 0% indicator but otherwise has no effect.
In the System Settings GUI there is a slider for backlight brightness but that is just stuck on 0% and won't move.
It feels like a system setting in Mint start up - maybe power saver?- which sets a default.
There is a text file: sys/class/leds/toshiba::illumination/subsystem/toshiba::illumination/device/kbd_backlight_mode with a single entry of 8 (whatever that means) but I can't find a way to edit it with it being a system file.
I've tried all the suggestions for a solution I can find online but none work.
Scanning the forum it seems to be a recurrent problem but I can't find a definitive solution. Anyone got any ideas?

[spamegg]

Hello lostintech welcome to the Forum.
Please share your system info by going to:
Menu/System Reports/System Information/click "Copy"
and pasting it here.
(You can use the command inxi -Fxxxmprz on the Terminal.)

[cbraxton]

In Mint: the backlight setting in BIOS is set to ON and the backlight comes on initially until Mint starts to load. At which point the backlight turns off and stays off. ...

I experienced the same behavior on my Lenovo laptop. I use the following quick and dirty shell script set to run when I log in, with sudo configured so brightnessctl can be run with the necessary privileges without requiring a password:

Code: Select all

#!/bin/sh
####################################################
# set 0 for off, 1 for 1/2 bright, 2 for full bright
####################################################

sudo brightnessctl --device='tpacpi::kbd_backlight' set 1
exit 0

Obviously you would need to change the brightnesctl command line for your hardware.

Another issue I've experienced is that if I close the laptop lid the screen and keyboard lights turn off but only the screen turns back on when the lid is opened back up. So I have a link to the script in my (Mate) panel to easily turn the keyboard light on again.

[lostintech]

Apologies for the delay - I got diverted.
Hopefully this is the info you requested
System:
Kernel: 5.15.0-102-generic x86_64 bits: 64 compiler: gcc v: 11.4.0
Desktop: Cinnamon 6.0.4 tk: GTK 3.24.33 wm: muffin dm: LightDM
Distro: Linux Mint 21.3 Virginia base: Ubuntu 22.04 jammy