LinuxQuestions.org
Go Job Hunting at the LQ Job Marketplace
Go Back   LinuxQuestions.org > Forums > Linux Forums > Linux - Software > Linux - Kernel
User Name
Password
Linux - Kernel This forum is for all discussion relating to the Linux kernel.

Notices



Reply
 
Search this Thread
Old 02-03-2012, 04:59 AM   #1
webquinty
Member
 
Registered: Apr 2008
Location: Espaņa
Distribution: Suse
Posts: 212

Rep: Reputation: 32
kernel drivers drm/i915 turn off backlight.


Hello,

I use Atom board that use drm/i915 driver to handle framebuffer.

I would like to use a function into this driver to turn off backlight but I nor sure how to make it.

For example, inside of intel_lvds.c, in drivers/gpu/drm/i915/ folder, there is a function to handle backlight:

static void intel_lvds_set_power(struct drm_device *dev, bool on)
static void intel_lvds_dpms(struct drm_encoder *encoder, int mode)

Could somebody help how to do it?

Best regards.
 
Old 02-03-2012, 08:25 AM   #2
webquinty
Member
 
Registered: Apr 2008
Location: Espaņa
Distribution: Suse
Posts: 212

Original Poster
Rep: Reputation: 32
Ok, I change the question.

Could I write a kernel driver to disable backlight on drm/i915 ?

Best regards
 
Old 02-05-2012, 09:36 AM   #3
lwasserm
Member
 
Registered: Mar 2008
Location: Baltimore Md
Distribution: ubuntu
Posts: 184

Rep: Reputation: 41
It's probably not necessary to write a driver. There is likely an interface to the backlight created under your /sys or /proc folders. The name may vary somewhat depending on your kernel and module versions. For instance, on my system, I can change backlight brightness by writing to /sys/class/backlight/acpi_video0/brightness.

You can also enter a parameter, (for brightness often to one of the ACPI modules), at boot to set a particular value. The details of doing so will vary with your distribution. In debian based systems, module options can be set using a file in /etc/modprobe.d

Last edited by lwasserm; 02-05-2012 at 09:43 AM.
 
Old 02-14-2012, 07:06 PM   #4
RandomTroll
Member
 
Registered: Mar 2010
Distribution: Slackware
Posts: 304

Rep: Reputation: 32
Have you tried setpci?

setpci -s 00:02.1 F4.B=0

works on my drm/i915 video computer.

Last edited by RandomTroll; 02-14-2012 at 07:16 PM.
 
  


Reply


Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is Off
HTML code is Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
drm/i915 can't work without intel_agp module ashish anand Linux - Kernel 1 12-07-2011 05:18 AM
xset does not turn off backlight neonsignal Linux - Hardware 4 07-28-2009 11:33 PM
Fedora 10: Is Intel GME965 using the wrong DRM module (i915)? smith Linux - Hardware 0 01-14-2009 04:56 PM
Force Backlight to turn off? mEo Linux - Laptop and Netbook 2 04-01-2008 02:40 PM
X not starting, DRM i810 X Drivers, Kernel 2.6.7 Syndrome Linux - Hardware 0 07-01-2004 06:47 AM


All times are GMT -5. The time now is 06:35 PM.

Main Menu
Advertisement
My LQ
Write for LQ
LinuxQuestions.org is looking for people interested in writing Editorials, Articles, Reviews, and more. If you'd like to contribute content, let us know.
Main Menu
Syndicate
RSS1  Latest Threads
RSS1  LQ News
Twitter: @linuxquestions
identi.ca: @linuxquestions
Facebook: linuxquestions Google+: linuxquestions
Open Source Consulting | Domain Registration