[ANNOUNCE] user_vc_blank-0.1 (blank the console using a userspace helper)

[Gene Pavlovsky <heilong@bluebottle.com>]

http://bugzilla.kernel.org/show_bug.cgi?id=4767

I think it'd be very good to have a console_blank_hook handler that would call a
userspace program/script/generate hotplug event whatever. Currently, the console
can only be blanked using APM, so no options exist for people using ACPI. I've
got a Radeon graphics chip on my laptop, and the LCD backlight can be controlled
(on/off) using radeontool. If there was a userspace callback interface to
console blanking, I would just make a callback script that calls "radeontool
light off" on blank and "radeontool light on" on unblank - really easy. I think
this userspace console_blank_hook handler is very simple to put into kernel, but
I'm not a kernel developer myself, so wouldn't risk sending any patches (that
call system("some_script")), because I probably won't make things as they should
be in the kernel.


------- Additional Comment #1 From Eugene Pavlovsky 2005-06-29 06:46 -------

Created an attachment (id=5238)
implemented this functionality in a kernel module

I've actually checked the kernel sources on how this can be done and
implemented the proposed functionality in a kernel module. The module attaches
a console blank hook function that uses kernel's call_usermodehelper() to
execute /sbin/user_vc_blank (defined at compile-time) to blank/unblank the
console. I've written a sample script (which I use on my laptop) that uses
radeontool to turn the LCD backlight off/on. Maybe this functionality should be
moved to the kernel. On the other hand, as it still needs userspace utilities,
maybe it's better off as a module. Anyway, please give it a thought, or at
least made this module available.

-- 
The human knowledge belongs to the world

Attachment: user_vc_blank-0.1.tar.gz
Description: GNU Zip compressed data