Can't set the keyboard backlight timeout on AC using stop_timeout

[anthon38]

Hello,
the laptop is an Inspiron 15 7510. The issue I'm running into is pretty much this: #48
meaning I can't set the keyboard backlight on AC using /sys/class/leds/dell::kbd_backlight/stop_timeout, except:

• I can set the value in the BIOS
• I can set the value using Dell Command configure (/opt/dell/dcc/cctk --kbdbacklighttimeoutac=15m for example)
• I can't set it using smbios-keyboard-ctl --set-timeout-ac=15m. This returns:

Traceback (most recent call last):
File "/usr/bin/smbios-keyboard-ctl", line 713, in
sys.exit( main() )
File "/usr/bin/smbios-keyboard-ctl", line 680, in main
raise RunTimeKeyboardErr("This system doesn't support AC timeout" )
main.RunTimeKeyboardErr: This system doesn't support AC timeout

• The token 0x451 is absent (smbios-token-ctl -i 0x451 returns nothing)

As per this comment #48 (comment)

If you can set it from there then we are looking at a bug in the implementation of detecting AC support is available.

I'm reporting this here.
I also don't know if it's related but while fiddling with this, I've been able to use the mouse as a start_trigger (only on battery, wasn't working at first; this never worked on ac), but now it won't work again... If it's completely unrelated, please let me know so I can investigate further this different issue.

[Theluga]

I want to add that the inspiron 13 7359 has a similar bug.

Setting the time out for the keyboard backlight worked for AC and Battery.

After some bios updates some years ago it stopped working. It only time-out now on battery.

But I cannot set it in bios. I can set on the OS but it is ignored when on AC.

Could you also help me?

I would not care if it was a quirky patch on the linux kernel or a new bios update.

Should I open a new issue?

I don't know if this is the right place to post this error.

Thank you!