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SubjectRe: [PATCH] Map volume and brightness events on thinkpads
On Mon, 15 Oct 2007, Jeremy Katz wrote:
> There are standard keycodes for brightness and volume; map the events to
> emit them so that things work properly

NAK. It is the completely wrong thing to do for IBM thinkpads which process
volume and brightness completely in firmware.

And the input subsystem maintainer has made it extremely clear in various
threads that the input devices are *not* to be used as a notification
service for on-screen-display or other such stuff. If you send volume and
brightness *key* events to userspace, it is supposed to act on them and
raise/lower brightness/volume, which is the wrong thing to do on thinkpads.
Never mind that HAL is ignoring the input maintainer's directions and
violating this.

We should fix the backlight class to be more useful and support poll() or
somesuch, for userspace to track the backlight level in a resource-friendly
way for OSD (the only sane thing to do on an IBM thinkpad with such events).
And an ALSA mixer to provide a proper path to the thinkpad-acpi volume
functionality is also in my schedule for 2.6.25.

As for Lenovo thinkpads, brightness control is to be processed by the ACPI
video module, so brightness hot keys are not to be reported by default there
either. I am not so sure about the volume keys, but your patch touches the
IBM keymap *and* you provide no testing information for the various Lenovo
models, so I have to NAK it as well until more information is available.

"One disk to rule them all, One disk to find them. One disk to bring
them all and in the darkness grind them. In the Land of Redmond
where the shadows lie." -- The Silicon Valley Tarot
Henrique Holschuh
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