Bug 499544

Summary:	app-laptop/laptop-mode-tools - defaults to wrong path /proc/acpi/video/VID/LCD/brightness
Product:	Gentoo Linux	Reporter:	Pavel Šimerda <code>
Component:	Current packages	Assignee:	Gentoo Linux bug wranglers <bug-wranglers>
Status:	RESOLVED UPSTREAM
Severity:	normal
Priority:	Normal
Version:	unspecified
Hardware:	All
OS:	Linux
URL:	https://wiki.gentoo.org/wiki/Power_management/HOWTO#Configuring_display_brightness
Whiteboard:
Package list:		Runtime testing required:	---

Description Pavel Šimerda 2014-01-28 06:34:57 UTC

Power management HOWTO claims that the default LCD brigtness path used by laptop_mode isn't supported by new kernels. That information is most probably pretty old already, so that path won't probably be supported by kernels run by Gentoo users already.

Source:

https://wiki.gentoo.org/wiki/Power_management/HOWTO#Configuring_display_brightness

I can confirm the nonexistence of that path on my Lenovo x201, as well as existence of the replacement suggested by the document:

/sys/class/backlight/acpi_video0/brightness

Could we please switch the default value to the path supported by current kernels?

Comment 1 Jeroen Roovers (RETIRED) gentoo-dev

2014-01-28 11:08:37 UTC

I suggest you get an account on https://wiki.gentoo.org/ and simply change it. As for app-laptop/laptop-mode-tools still referring to the deprecated /proc/acpi, that's a matter for its upstream developers to fix.

Comment 2 Pavel Šimerda 2014-01-28 15:51:06 UTC

I reported a bug in the [default] contents of a configuration file distributed as part of the app-laptop/laptop-mode-tools to help other Gentoo users avoid having to replace the obsolete path with the correct path.

It's a trivial replacement that can be handled by a single 'sed' line in the ebuild. I can supply a patch for the ebuild if requested.

(In reply to Jeroen Roovers from comment #1)
> I suggest you get an account on https://wiki.gentoo.org/

I do have one:

https://wiki.gentoo.org/wiki/User:Pavlix

> and simply change it.

The Wiki correctly describes the very issue I'm reporting. We shouldn't change that until a fixed version of the package is available in the stable branch of Gentoo. The only sane thing I can do now is to refer to this closed bug report in the Wiki.

> As for app-laptop/laptop-mode-tools still referring to the deprecated
> /proc/acpi, that's a matter for its upstream developers to fix.

I admit a bug in default configuration is not a particularly blocking issue and it's documented in the HOWTO, after all, but why don't we apply a trivial fix when it's available?