[SOLVED] acpi backlight always maxed out when switching from X to tty

kokoko3k · 2014-09-02 09:04:11

If i set the acpi brightness on my notebook (n280) (or on my laptop -ivybridge-) under X, that setting is not preserved when i go to a tty, but is set to 100%

The opposite works (setting backlight under the tty console is preserved when switching to X)

As said, happens on two different systems (both intel gpus).
Anybody can observe the same and/or have workarounds? thanks.

 # cat /proc/cmdline
root=/dev/disk/by-uuid/5404b3fb-ec84-4afc-9b0b-c9891615069d resume=/dev/sda2 ro quiet acpi_osi=Linux i915.lvds_downclock=1 i915.modeset=1 i915.i915_enable_rc6=1 i915.i915_enable_fbc=1 pcie_aspm=force acpi_sleep=nonvs nomce drm.vblankoffdelay=1 threadirqs

Last edited by kokoko3k (2014-11-03 12:11:20)

jdbrown · 2014-09-03 01:04:39

Seems to be fixed upstream, will be included in the next version of xf86-video-intel.
http://cgit.freedesktop.org/xorg/driver … 0d681c171e

kokoko3k · 2014-09-03 11:13:19

Oh, thanks for pointing me to the bug report.
Marking as solved, great

tolga9009 · 2014-09-13 08:34:47

Hi,

xf86-video-intel 2.99.916-1 - released a couple of days ago and including the patch above - didn't solve the issue for me. I'm using a Dell M3800 + Gnome + GDM with latest packages. I've noticed, that if I disable gdm and reboot, there is no issue. systemd-backlight correctly saves the backlight-level and restores it upon next boot. When gdm is shut down, during poweroff, the problem occurs: for some odd reason, intel_backlight is getting set to a maximum and systemd-backlight stores the wrong value. There seems nothing wrong with systemd-backlight; the culprit is either xf86-video-intel or Gnome / gdm.

I don't remember the exact date, but about 3 months ago, saving and restoring backlight-levels were working like a charm. Some update broke it for me - I don't know which one, as I didn't care back then.

Does anyone have an idea, where the problem is?

Cheers,
Tolga

kokoko3k · 2014-09-13 13:24:48

~~I still haven't tested it, but i toke a look to the source, and~~ the patch is there.
-EDIT-
Just tested, indeed the problem is NOT solved, changing the thread title now.
If i switch to uxa, all works as expected.

Reported here:
https://bugs.freedesktop.org/show_bug.cgi?id=83816

Last edited by kokoko3k (2014-09-13 13:42:04)

kokoko3k · 2014-09-13 15:34:02

Chris wilson answered that thepatch is ineffective "because is not a ddx bug"
Not sure what it means; maybe is in the kernel?

tolga9009 · 2014-09-14 17:03:46

@kokoko3k: thank you for reporting this bug. I've tried switching from X to console via STRG+ALT+F[2-6] and I can see, what's wrong: switching from X to console sets the brightness to maximum, switching back to X (using STRG+ALT+F1) restores the brightness-level.

If I lower the brightness in console using echo method, switch to X and switch back again, the brightness-level gets overwritten and is set to a maximum again. Unfortunately, I have absolutely NO IDEA, what the cause might be. I will try out Ubuntu's Live CD, and see if there are similar problems or not.

k4rtik · 2014-09-24 04:01:31

Facing same problem.

$ pacman -Q xf86-video-intel
xf86-video-intel 2.99.916-2
$ pacman -Q systemd
systemd 216-3

tolga9009 · 2014-11-02 18:51:16

I'm not a fan of necrobumping, but I just wanted to add, that this problem is now solved with upstream packages. Worked for me, this can be marked as solved.

forumache · 2014-11-03 11:15:00

Thanks for necrobumping @tolga9009! (and I don't even think it was a dead thread).
I had a systemd script overriding the default behavior: instead of saving the brightness on shutdown, I saved it before killing gdm (so it was still in graphical mode, saving the proper value not the max brightness in text mode).

I left that modified systemd unit but now I can get rid of it, thanks to your notification that the bug was solved. I confirm, it doesn't affect me anymore

Last edited by forumache (2014-11-03 11:15:25)

Arch Linux

#1 2014-09-02 09:04:11

[SOLVED] acpi backlight always maxed out when switching from X to tty

#2 2014-09-03 01:04:39

Re: [SOLVED] acpi backlight always maxed out when switching from X to tty

#3 2014-09-03 11:13:19

Re: [SOLVED] acpi backlight always maxed out when switching from X to tty

#4 2014-09-13 08:34:47

Re: [SOLVED] acpi backlight always maxed out when switching from X to tty

#5 2014-09-13 13:24:48

Re: [SOLVED] acpi backlight always maxed out when switching from X to tty

#6 2014-09-13 15:34:02

Re: [SOLVED] acpi backlight always maxed out when switching from X to tty

#7 2014-09-14 17:03:46

Re: [SOLVED] acpi backlight always maxed out when switching from X to tty

#8 2014-09-24 04:01:31

Re: [SOLVED] acpi backlight always maxed out when switching from X to tty

#9 2014-11-02 18:51:16

Re: [SOLVED] acpi backlight always maxed out when switching from X to tty

#10 2014-11-03 11:15:00

Re: [SOLVED] acpi backlight always maxed out when switching from X to tty

Board footer