* [gentoo-user] Where does /sys/class/backlight/intel_backlight come from?
@ 2012-03-16 20:14 Grant
2012-03-16 20:18 ` Canek Peláez Valdés
2012-03-16 21:31 ` Paul Hartman
0 siblings, 2 replies; 6+ messages in thread
From: Grant @ 2012-03-16 20:14 UTC (permalink / raw
To: Gentoo mailing list
Does anyone know which kernel option would be responsible for
/sys/class/backlight/intel_backlight? I've disabled some backlight
stuff in the kernel but the directory still appears. I get screen
backlight control on my laptop if I do:
echo 0 > /sys/class/backlight/intel_backlight/brightness
but if xlockmore blanks my screen, I have to issue the above again
before screen backlight control works again. I also have acpi_video0
in /sys/class/backlight and I think removing intel_backlight might fix
the problem.
I could try deleting the directory. Is that safe? Are the files and
folders in /sys generated dynamically at boot?
- Grant
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [gentoo-user] Where does /sys/class/backlight/intel_backlight come from?
2012-03-16 20:14 [gentoo-user] Where does /sys/class/backlight/intel_backlight come from? Grant
@ 2012-03-16 20:18 ` Canek Peláez Valdés
2012-03-17 0:12 ` Grant
2012-03-16 21:31 ` Paul Hartman
1 sibling, 1 reply; 6+ messages in thread
From: Canek Peláez Valdés @ 2012-03-16 20:18 UTC (permalink / raw
To: gentoo-user
On Fri, Mar 16, 2012 at 2:14 PM, Grant <emailgrant@gmail.com> wrote:
> Does anyone know which kernel option would be responsible for
> /sys/class/backlight/intel_backlight? I've disabled some backlight
> stuff in the kernel but the directory still appears. I get screen
> backlight control on my laptop if I do:
>
> echo 0 > /sys/class/backlight/intel_backlight/brightness
>
> but if xlockmore blanks my screen, I have to issue the above again
> before screen backlight control works again. I also have acpi_video0
> in /sys/class/backlight and I think removing intel_backlight might fix
> the problem.
>
> I could try deleting the directory. Is that safe? Are the files and
> folders in /sys generated dynamically at boot?
The /sys directory is like /proc; it's a virtual directory which
serves as interface to several kernel knobs. I don't think you can
remove any dir from it, and if you do, next boot it will show up
again.
Regards.
--
Canek Peláez Valdés
Posgrado en Ciencia e Ingeniería de la Computación
Universidad Nacional Autónoma de México
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [gentoo-user] Where does /sys/class/backlight/intel_backlight come from?
2012-03-16 20:18 ` Canek Peláez Valdés
@ 2012-03-17 0:12 ` Grant
0 siblings, 0 replies; 6+ messages in thread
From: Grant @ 2012-03-17 0:12 UTC (permalink / raw
To: gentoo-user
>> Does anyone know which kernel option would be responsible for
>> /sys/class/backlight/intel_backlight? I've disabled some backlight
>> stuff in the kernel but the directory still appears. I get screen
>> backlight control on my laptop if I do:
>>
>> echo 0 > /sys/class/backlight/intel_backlight/brightness
>>
>> but if xlockmore blanks my screen, I have to issue the above again
>> before screen backlight control works again. I also have acpi_video0
>> in /sys/class/backlight and I think removing intel_backlight might fix
>> the problem.
>>
>> I could try deleting the directory. Is that safe? Are the files and
>> folders in /sys generated dynamically at boot?
>
> The /sys directory is like /proc; it's a virtual directory which
> serves as interface to several kernel knobs. I don't think you can
> remove any dir from it, and if you do, next boot it will show up
> again.
You're right, "operation not permitted" there.
- Grant
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [gentoo-user] Where does /sys/class/backlight/intel_backlight come from?
2012-03-16 20:14 [gentoo-user] Where does /sys/class/backlight/intel_backlight come from? Grant
2012-03-16 20:18 ` Canek Peláez Valdés
@ 2012-03-16 21:31 ` Paul Hartman
2012-03-17 2:32 ` Grant
1 sibling, 1 reply; 6+ messages in thread
From: Paul Hartman @ 2012-03-16 21:31 UTC (permalink / raw
To: gentoo-user
On Fri, Mar 16, 2012 at 3:14 PM, Grant <emailgrant@gmail.com> wrote:
> Does anyone know which kernel option would be responsible for
> /sys/class/backlight/intel_backlight? I've disabled some backlight
> stuff in the kernel but the directory still appears. I get screen
> backlight control on my laptop if I do:
Probably from the intel video driver (i915 or whatever)
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [gentoo-user] Where does /sys/class/backlight/intel_backlight come from?
2012-03-16 21:31 ` Paul Hartman
@ 2012-03-17 2:32 ` Grant
2012-03-17 16:36 ` Grant
0 siblings, 1 reply; 6+ messages in thread
From: Grant @ 2012-03-17 2:32 UTC (permalink / raw
To: gentoo-user
>> Does anyone know which kernel option would be responsible for
>> /sys/class/backlight/intel_backlight? I've disabled some backlight
>> stuff in the kernel but the directory still appears. I get screen
>> backlight control on my laptop if I do:
>
> Probably from the intel video driver (i915 or whatever)
Sounds like I won't be able to remove it without removing support for
my video card.
I have to enter 'echo 0 >
/sys/class/backlight/intel_backlight/brightness' again every time
xlockmore comes on. Does anyone know what's going on there?
- Grant
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [gentoo-user] Where does /sys/class/backlight/intel_backlight come from?
2012-03-17 2:32 ` Grant
@ 2012-03-17 16:36 ` Grant
0 siblings, 0 replies; 6+ messages in thread
From: Grant @ 2012-03-17 16:36 UTC (permalink / raw
To: gentoo-user
[snip]
> I have to enter 'echo 0 >
> /sys/class/backlight/intel_backlight/brightness' again every time
> xlockmore comes on. Does anyone know what's going on there?
>
> - Grant
Strangely, this isn't required unless xlockmore has been running for
at least a few minutes. Does it sound like this is induced by
xlockmore behavior or Xorg or something else?
- Grant
^ permalink raw reply [flat|nested] 6+ messages in thread
end of thread, other threads:[~2012-03-17 16:37 UTC | newest]
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2012-03-16 20:14 [gentoo-user] Where does /sys/class/backlight/intel_backlight come from? Grant
2012-03-16 20:18 ` Canek Peláez Valdés
2012-03-17 0:12 ` Grant
2012-03-16 21:31 ` Paul Hartman
2012-03-17 2:32 ` Grant
2012-03-17 16:36 ` Grant
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