No backlight control in Dell studio 1569

JAORMX · 2010-12-31 03:08:29

Hi, I bought a Dell Studio 1569 recently, and installed Archlinux to it, everythings working great, except for the brightness of the screen which i cannot adjust the brightness of the screen.
uname -a: 2.6.36-ARCH #1 SMP PREEMPT Fri Dec 10 20:32:37 CET 2010 x86_64 Intel(R) Core(TM) i5 CPU M 450 @ 2.40GHz GenuineIntel GNU/Linux

lspci | grep VGA

00:02.0 VGA compatible controller: Intel Corporation Core Processor Integrated Graphics Controller (rev 18)

I already tried:

disabling KMS
Setting the backlight control to the vendor in grub
Setting the backlight control to "native" with xrandr
Changing the brightness manually by changing the value of the file atual_brightness and brightness in /sys/class/backlight/acpi_video0

With no results in what I did.
The function keys work, and when I try to change thr brightness through the function keys, the "brightness icon" and the bar appears, and it changes, I mean, it seems to catch the event.
Also, when I change the brightness during the time grub is in control, it works, but it doesn't when arch boots, and the brightness I set on the grub screen isn't saved.

Any ideas?

MadTux · 2010-12-31 06:42:49

Does your bios allow to set the initial brightness level?

JAORMX · 2010-12-31 18:07:30

If it does I haven't found where

Daniel_F · 2010-12-31 19:01:04

Try executing this as root:

setpci -s 00:02.0 F4.B=7F

and see if the brightness changes.

The 7F is just an example, you can set any value from 00 to FF, where FF is 100% (7F = 50%)

JAORMX · 2010-12-31 19:04:04

The brightness doesn't change

Daniel_F · 2010-12-31 19:24:09

did you get an error message or just nothing ??

JAORMX · 2010-12-31 19:25:19

just nothing

Daniel_F · 2010-12-31 20:34:14

I did a little research and apparently it is a known compatibility problem with DELL's flaky ACPI.

I found this kernel patch that is supposed to fix it.

http://web.archiveorange.com/archive/v/ … E2zuxpV8jt

If you are willing to compile a custom kernel this could be the solution for your problem.

Or perhaps one of the kernel wizards around here can do it and put it up on AUR ??

medianmajik · 2011-01-06 08:48:57

Daniel_F wrote:

Try executing this as root:
setpci -s 00:02.0 F4.B=7F
and see if the brightness changes.
The 7F is just an example, you can set any value from 00 to FF, where FF is 100% (7F = 50%)

This works perfectly for me. Currently have limited backlight control via keyboard; I can only go from 100% to about 65% with HP Mini 1125 netbook function keys. Just need to figure out how to fix this via the brightness function keys

TheAmigo · 2011-01-22 04:09:19

Daniel_F wrote:

I did a little research and apparently it is a known compatibility problem with DELL's flaky ACPI.
I found this kernel patch that is supposed to fix it.
http://web.archiveorange.com/archive/v/ … E2zuxpV8jt
If you are willing to compile a custom kernel this could be the solution for your problem.

I've been using that patch on my Dell Studio 1558 (no discrete GPU) since 2.6.34. I've had to tweak it a bit to apply to 2.6.36, but it still works great.

2.6.37, however is a bit different and some changes need to be made to that patch before it can be applied. Since there were so many changes, I tried a vanilla 2.6.37 to see if it works unpatched, but it doesn't.

I'll play around with it a bit and see if I can figure it out... but I don't have great hope that I'll figure it out.

miko · 2011-01-31 15:04:36

TheAmigo wrote:

2.6.37, however is a bit different and some changes need to be made to that patch before it can be applied. Since there were so many changes, I tried a vanilla 2.6.37 to see if it works unpatched, but it doesn't.
I'll play around with it a bit and see if I can figure it out... but I don't have great hope that I'll figure it out.

Hello,
I have a Dell Latitude E6400. Everything worked OK for me until today, when I upgraded the kernel from 2.6.36 to 2.6.37. Now, if I change the value (with above setcpi command) to 0, then the screen is totally black (I mean, it is really black, unlike changing the brightness down to 0, which still gives some brightness), and then I am not able to make it bright again. My external monitor works OK.
I noticed this only because the screensaver blanks the screen when idle, and today I was not able to get my screen back from the screensaver
Will be looking for a fix. Until then, a simple workaround with suspend to RAM and then waking up brings the backlight back.

miko · 2011-01-31 15:27:08

FYI: there is a bug tracker: https://bugzilla.kernel.org/show_bug.cgi?id=22672

JAORMX · 2011-01-31 15:29:53

Uhm...I don't think that's the same problem I have, perhaps I should file a new bug. I hope that bug can be fixed too.

Last edited by JAORMX (2011-01-31 15:31:58)

miko · 2011-02-02 09:42:17

FYI: I have installed a new kernel (kernel26-mainline from AUR, which is 2.6.36rc2) and it fixed my problem.

russman_dncl · 2011-02-04 10:07:28

miko wrote:

I have a Dell Latitude E6400. Everything worked OK for me until today, when I upgraded the kernel from 2.6.36 to 2.6.37. Now, if I change the value (with above setcpi command) to 0, then the screen is totally black (I mean, it is really black, unlike changing the brightness down to 0, which still gives some brightness), and then I am not able to make it bright again. My external monitor works OK.
I noticed this only because the screensaver blanks the screen when idle, and today I was not able to get my screen back from the screensaver
Will be looking for a fix. Until then, a simple workaround with suspend to RAM and then waking up brings the backlight back.

I have the same with my latitude 420. I will try to downgrade the kernel. Thanks for the hint.

epsilom · 2011-03-13 23:24:28

try using this kernel: https://aur.archlinux.org/packages.php?ID=47386

TheAmigo · 2011-03-16 02:51:23

epsilom wrote:

try using this kernel: https://aur.archlinux.org/packages.php?ID=47386

That solves my problem! Thanks for the link, epsilom!

Although, I didn't install that from AUR... I followed the link and applied the patches to a fresh kernel for a couple reasons: it was 2.6.38-rc7 (the patch applied to 2.6.38 just fine), and as it was the whole kernel source tree, I was afraid that it might have some other random Ubuntu-specific patches applied.

It's probably not a coincidence that that's the same guy who fixed it for 2.6.32 (my link above).

VALIS · 2011-03-22 21:07:43

Does this work for KDE 4.6?

I read this on Kamal Mostafa's page:

NOTES FOR KDE DESKTOP USERS
KDE desktop users: This PPA may NOT fix your backlight control hotkeys: This fix requires a kernel module to supply the new /sys/class/backlight/intel_backlight interface (which will work regardless of your desktop) and also a desktop module to access that interface. For Gnome, the updated gnome-power-manager in this PPA supplies that, but the equivalent for KDE has not yet been developed.

TheAmigo · 2011-03-23 01:41:07

I'm using Xfce, so I didn't apply the gnome-power-manager patch, nor do I know if it works for KDE.

I do know that after applying the kernel patch, not only do the hotkeys work (before the hotkeys just showed the on-screen brightness control, but had no actual effect), xbacklight and redshift also work. I don't know if that really means anything or if all three are really just using the same API.

If I get a chance, I can try installing KDE to see if it works there too.

Arch Linux

#1 2010-12-31 03:08:29

No backlight control in Dell studio 1569

#2 2010-12-31 06:42:49

Re: No backlight control in Dell studio 1569

#3 2010-12-31 18:07:30

Re: No backlight control in Dell studio 1569

#4 2010-12-31 19:01:04

Re: No backlight control in Dell studio 1569

#5 2010-12-31 19:04:04

Re: No backlight control in Dell studio 1569

#6 2010-12-31 19:24:09

Re: No backlight control in Dell studio 1569

#7 2010-12-31 19:25:19

Re: No backlight control in Dell studio 1569

#8 2010-12-31 20:34:14

Re: No backlight control in Dell studio 1569

#9 2011-01-06 08:48:57

Re: No backlight control in Dell studio 1569

#10 2011-01-22 04:09:19

Re: No backlight control in Dell studio 1569

#11 2011-01-31 15:04:36

Re: No backlight control in Dell studio 1569

#12 2011-01-31 15:27:08

Re: No backlight control in Dell studio 1569

#13 2011-01-31 15:29:53

Re: No backlight control in Dell studio 1569

#14 2011-02-02 09:42:17

Re: No backlight control in Dell studio 1569

#15 2011-02-04 10:07:28

Re: No backlight control in Dell studio 1569

#16 2011-03-13 23:24:28

Re: No backlight control in Dell studio 1569

#17 2011-03-16 02:51:23

Re: No backlight control in Dell studio 1569

#18 2011-03-22 21:07:43

Re: No backlight control in Dell studio 1569

#19 2011-03-23 01:41:07

Re: No backlight control in Dell studio 1569

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