Re: [gentoo-user] Re: Backlight problems

[Mark Knecht <markknecht@gmail.com>]

On Fri, Mar 16, 2012 at 11:55 AM, Grant <emailgrant@gmail.com> wrote:
<SNIP>
>> Grant,
>>   Sorry I missed this thread earlier. I've got an Asus 17" laptop
>> that I've been trying unsuccessfully to get the keyboard backlighting
>> to work correctly for weeks (maybe months - I no longer remember how
>> long) On my machine I get keyboard backlighting when I boot the
>> machine, but if I turn off the lights with the switch on the machine I
>> cannot so far turn them back on by any means.
>>
>>   On this machine xbacklight -get responds that nothing has backlight
>> properties so I've clearly got some configuration issues.
>>
>>   As for the kernel I'm using vanilla-sources-3.2.10 so I don't think
>> there's a lot that is newer than that.
>>
>>   I don't care much about screen backlighting but keyboard
>> backlighting is important to me.
>>
>> - Mark
>
> Hey Mark, I'm happy to say I just fixed the screen backlighting on my
> system, but I'm sorry to say I don't think it will help you with
> keyboard backlighting.  To fix it, I removed 'acpi_backlight=vendor'
> from grub and added 'echo 0 >
> /sys/class/backlight/intel_backlight/brightness' to
> /etc/local.d/backlight.start and made that file executable.  Now
> backlight control works perfectly via the keyboard shortcuts with no
> other configuration and no xbacklight.  I'm on
> hardened-sources-3.2.2-r1.
>
> BTW, I noticed baselayout1.start and baselayout1.stop are no longer
> created in /etc/local.d.
>
> - Grant
>

Hi Grant,
   OK, that's interesting info. Here's what I'm currently seeing:

slinky ~ # uname -a
Linux slinky 3.2.10 #1 SMP PREEMPT Tue Mar 13 09:45:35 PDT 2012 x86_64
Intel(R) Core(TM) i7 CPU Q 740 @ 1.73GHz GenuineIntel GNU/Linux
slinky ~ # ls -al /etc/local.d/
total 20
drwxr-xr-x  2 root root 4096 Feb 23 21:03 .
drwxr-xr-x 72 root root 4096 Mar 16 11:53 ..
-rw-r--r--  1 root root  387 Feb 23 21:03 README
-rwxr-xr-x  1 root root  123 May  3  2011 baselayout1.start
-rwxr-xr-x  1 root root  217 May  3  2011 baselayout1.stop
slinky ~ # ls -la /sys/class/backlight/asus_laptop/
total 0
drwxr-xr-x 2 root root    0 Mar 16 04:35 .
drwxr-xr-x 3 root root    0 Mar 16 04:35 ..
-r--r--r-- 1 root root 4096 Mar 16 12:09 actual_brightness
-rw-r--r-- 1 root root 4096 Mar 16 12:09 bl_power
-rw-r--r-- 1 root root 4096 Mar 16 11:40 brightness
lrwxrwxrwx 1 root root    0 Mar 16 12:09 device ->
../../../asus_laptop
-r--r--r-- 1 root root 4096 Mar 16 11:40 max_brightness
lrwxrwxrwx 1 root root    0 Mar 16 04:35 subsystem ->
../../../../../class/backlight
-r--r--r-- 1 root root 4096 Mar 16 12:09 type
-rw-r--r-- 1 root root 4096 Mar 16 04:35 uevent
slinky ~ # cat /sys/class/backlight/asus_laptop/brightness
15
slinky ~ #

   So, it seems to me that following your example, if I wanted to
experiment with screen backlighting what would I do? I'm in KDE BTW in
case we're doing something different in that regard.

   I see in the Global Keyboard Shortcuts in KDE that there are
Monitor Brightness Down/Up controls defined but I'm not understanding
what keys actually control those. I  Googled around for a minute and
found Fn-ArrowUp/ArrowDn but they didn't work o I'm hoping you can
tell me and save me a few minutes. Maybe it's because I haven't
started something required?

   acpi_listen on n-ArrowUp/Dn does produce a response so maybe I
don't have something properly mapped?

   I do have baselayout1.start/stop stuff so it seems our systems are
fairly different.

Thank in advance,
Mark