Arch Linux

Satani-Saul

Member

Registered: 2023-03-21

Posts: 1

[solved] Keyboard Backlight Without Time Out on AC dell-laptop Quirk

Hello, good morning!

I use arch since some years ago, but I am not that knowledgeable.

I will start with the context. I have a Dell laptop that is already EOL and my bios is bugged, it's the Inspiron 13-7359

I have the exactly same issue on this link https://github.com/dell/libsmbios/issues/48

the 0x451 token is absent but my laptop could timeout on AC before some updates on the IntelME (that cannot be removed) I tried writing with msrtools but it cannot be done because it's not on the cpu...

In the same link you can see that Venemo pushed a patch to the kernel that solved his problem, but he did with a dmi specific quirk

on the dell-laptop driver we can see that it already exists there:

from:

https://github.com/torvalds/linux/blob/ … l-laptop.c

in line 70 and 71:

 
static struct quirk_entry quirk_dell_xps13_9370 = {
	.kbd_missing_ac_tag = true,

And in line 308~315:

{
		.callback = dmi_matched,
		.ident = "Dell XPS 13 9370",
		.matches = {
			DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
			DMI_MATCH(DMI_PRODUCT_NAME, "XPS 13 9370"),
		},
		.driver_data = &quirk_dell_xps13_9370,
	},

in line 1453~1455

	if ((quirks && quirks->kbd_missing_ac_tag) ||
	    dell_smbios_find_token(KBD_LED_AC_TOKEN))
		kbd_timeout_ac_supported = true;

I created a file in /etc/modprobe.d/dell-laptop.conf

I want to be able to manually enable this quirk on my machine without pushing a new dmi specific quirk patch to the linux kernel or having to compile a new one, and a bios update is unlikely since my computer is already EOL.

In my file I tried writing:

 modprobe dell-laptop kbd_timeout_ac_supported = true 

and

 modprobe dell-laptop kbd_missing_ac_tag = true 

and

 modprobe dell-laptop quirk=quirk_dell_xps13_9370 

None of these seemed to work.

Could anyone help me how to enable this quirk manually to get my backlight time out working again, please?

Thank you for your time reading my question.

Edit: Thanks!

Last edited by Satani-Saul (2024-04-02 18:05:52)

theluga

Member

Registered: 2023-12-23

Posts: 24

Re: [solved] Keyboard Backlight Without Time Out on AC dell-laptop Quirk

I don't know about how to fix the bios. But I did a couple of bash scripts that manually set the time out of the keyboard.

It's some bad bash code and just some services that I use and you could try to adapt it for your needs if it's doable.

I have the exact same laptop. And this bios bug was frustrating.

https://github.com/Theluga/Keyboard-light-timeout

In this repo, there is a bash script to time out the keyboard backlight on gnome with a wayland session.

And a bash script to time out the keyboard backlight on X but I only tested on xfce.

I hope it helps!