Re: [PATCH] thinkpad_acpi: Add support for keyboard backlight

From: Pali RohÃr
Date: Mon Jan 04 2016 - 15:24:00 EST


On Monday 04 January 2016 21:12:31 Pavel Machek wrote:
> Hi1
>
> > This patch adds support for controlling keyboard backlight via
> > standard linux led class interface (::kbd_backlight). It uses ACPI
> > HKEY device with MLCG and MLCS methods.
> >
> > Signed-off-by: Pali RohÃr <pali.rohar@xxxxxxxxx>
> > Tested-by: Fabio D'Urso <fabiodurso@xxxxxxxxxx>
>
> On my thinkpad, keyboard light is controlled by
>
> /sys/class/leds/tpacpi\:\:thinklight/brightness
>
> (that's a bad name).

Hi!

That is light in upper case of bezel/display, right? Thinklight is
probably official marketing name for that by IBM/Lenovo.

My patch adds support for keyboard backlight (light under the keyboard).

> On n900, it is .../leds/kb0..kb6. Now we'd have kbd_backlight. I
> guess we should standartize on one name for this light, so that
> userspace has the chance to handle it automatically...

Looks like userspace already uses /sys/class/leds/*::kbd_backlight for
keyboard backlight (light under the keyboard). At least other drivers
uses this name and my KDE desktop recognized "dell::kbd_backlight" (from
dell-laptop.ko) and "tpacpi::kbd_backlight" too.

So really for keyboard backlight use *::kbd_backlight it is already
handled by existing userspace applications.

> Also, neccessity of workqueues for LED setting is slowly being
> removed from the kernel, see LED mailing list for details.

My patch uses kbd_backlight LED in same as as other LEDs in thinkpad
acpi driver.

--
Pali RohÃr
pali.rohar@xxxxxxxxx

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