[solved] ACPI cannot control screen brightness anymore

willardthor · 2014-03-04 20:52:03

Hi,

I did an upgrade recently, after which I stopped being able to increase / decrease brightness using FN / function keys on my keyboard. My laptop is an Asus EEE 1015PEM.

I checked if ACPI was receiving the right signals. It was.

$ cat /sys/class/backlight/acpi_video0/brightness 
10
$ # reducing brightness by 4
$ cat /sys/class/backlight/acpi_video0/brightness 
6
$ # but there was no change in brightness.
$

After reading this and similar Google search results, I tried adding

acpi_osi=Linux acpi_backlight=vendor

to my kernel parameters by following these directions, which gave super-high brightness which could not be controlled through function keys. I removed

acpi_backlight=vendor

and now the screen is tolerable, but I am still unable to control its brightness.

What do I do?

Kind regards,
Willard.

P.S.: In case this is useful:

$ cat /etc/default/grub | grep GRUB_CMDLINE_LINUX_DEFAULT
GRUB_CMDLINE_LINUX_DEFAULT="quiet acpi_osi=Linux"

$ lspci
00:00.0 Host bridge: Intel Corporation Atom Processor D4xx/D5xx/N4xx/N5xx DMI Bridge (rev 02)
00:02.0 VGA compatible controller: Intel Corporation Atom Processor D4xx/D5xx/N4xx/N5xx Integrated Graphics Controller (rev 02)
00:02.1 Display controller: Intel Corporation Atom Processor D4xx/D5xx/N4xx/N5xx Integrated Graphics Controller (rev 02)
00:1b.0 Audio device: Intel Corporation NM10/ICH7 Family High Definition Audio Controller (rev 02)
00:1c.0 PCI bridge: Intel Corporation NM10/ICH7 Family PCI Express Port 1 (rev 02)
00:1c.1 PCI bridge: Intel Corporation NM10/ICH7 Family PCI Express Port 2 (rev 02)
00:1c.3 PCI bridge: Intel Corporation NM10/ICH7 Family PCI Express Port 4 (rev 02)
00:1d.0 USB controller: Intel Corporation NM10/ICH7 Family USB UHCI Controller #1 (rev 02)
00:1d.1 USB controller: Intel Corporation NM10/ICH7 Family USB UHCI Controller #2 (rev 02)
00:1d.2 USB controller: Intel Corporation NM10/ICH7 Family USB UHCI Controller #3 (rev 02)
00:1d.3 USB controller: Intel Corporation NM10/ICH7 Family USB UHCI Controller #4 (rev 02)
00:1d.7 USB controller: Intel Corporation NM10/ICH7 Family USB2 EHCI Controller (rev 02)
00:1e.0 PCI bridge: Intel Corporation 82801 Mobile PCI Bridge (rev e2)
00:1f.0 ISA bridge: Intel Corporation NM10 Family LPC Controller (rev 02)
00:1f.2 SATA controller: Intel Corporation NM10/ICH7 Family SATA Controller [AHCI mode] (rev 02)
01:00.0 Ethernet controller: Qualcomm Atheros AR8132 Fast Ethernet (rev c0)
02:00.0 Network controller: Broadcom Corporation BCM4313 802.11bgn Wireless Network Adapter (rev 01)

$ lsusb
Bus 005 Device 002: ID 13d3:5702 IMC Networks UVC VGA Webcam
Bus 005 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub
Bus 004 Device 002: ID 13d3:3315 IMC Networks Bluetooth module
Bus 004 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub
Bus 003 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub
Bus 002 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub
Bus 001 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub

$ lsmod
lsmod
Module                  Size  Used by
joydev                  9631  0 
mousedev               10247  0 
arc4                    2000  2 
btusb                  19648  0 
bluetooth             326343  2 btusb
uvcvideo               72804  0 
videobuf2_vmalloc       3304  1 uvcvideo
videobuf2_memops        2335  1 videobuf2_vmalloc
videobuf2_core         28243  1 uvcvideo
videodev              111840  2 uvcvideo,videobuf2_core
brcmsmac              512878  0 
media                  11719  2 uvcvideo,videodev
cordic                  1112  1 brcmsmac
brcmutil                4573  1 brcmsmac
b43                   365189  0 
coretemp                6358  0 
mac80211              474681  2 b43,brcmsmac
cfg80211              408199  3 b43,brcmsmac,mac80211
ssb                    55595  1 b43
mmc_core               95465  2 b43,ssb
asus_wmi               16274  0 
iTCO_wdt                5407  0 
iTCO_vendor_support     1929  1 iTCO_wdt
pcmcia                 45492  2 b43,ssb
sparse_keymap           3146  1 asus_wmi
pcmcia_core            14232  1 pcmcia
rfkill                 15651  3 cfg80211,bluetooth,asus_wmi
microcode              15216  0 
evdev                  11045  12 
psmouse                88171  0 
serio_raw               5009  0 
pcspkr                  2027  0 
atl1c                  36834  0 
lpc_ich                13368  0 
thermal                 8556  0 
i915                  725594  2 
snd_hda_codec_realtek    45083  1 
drm_kms_helper         35710  1 i915
snd_hda_intel          37352  0 
snd_hda_codec         150017  2 snd_hda_codec_realtek,snd_hda_intel
drm                   239102  3 i915,drm_kms_helper
snd_hwdep               6332  1 snd_hda_codec
battery                 7565  0 
video                  11425  2 i915,asus_wmi
snd_pcm                77822  2 snd_hda_codec,snd_hda_intel
ac                      3334  0 
snd_page_alloc          7298  2 snd_pcm,snd_hda_intel
wmi                     8251  1 asus_wmi
snd_timer              18718  1 snd_pcm
acpi_cpufreq           10215  1 
bcma                   36288  3 b43,brcmsmac
intel_agp              10872  1 i915
snd                    59029  6 snd_hda_codec_realtek,snd_hwdep,snd_timer,snd_pcm,snd_hda_codec,snd_hda_intel
i2c_algo_bit            5391  1 i915
button                  4605  1 i915
intel_gtt              12664  3 i915,intel_agp
i2c_core               24760  5 drm,i915,drm_kms_helper,i2c_algo_bit,videodev
shpchp                 25425  0 
soundcore               5418  1 snd
processor              24620  1 acpi_cpufreq
ext4                  473259  3 
crc16                   1359  2 ext4,bluetooth
mbcache                 6074  1 ext4
jbd2                   80912  1 ext4
sd_mod                 31361  4 
atkbd                  16806  0 
libps2                  4187  2 atkbd,psmouse
ahci                   23048  3 
libahci                21698  1 ahci
libata                172104  2 ahci,libahci
uhci_hcd               24755  0 
ehci_pci                3928  0 
ehci_hcd               64171  1 ehci_pci
scsi_mod              132250  2 libata,sd_mod
usbcore               180208  5 btusb,uhci_hcd,uvcvideo,ehci_hcd,ehci_pci
usb_common              1648  1 usbcore
i8042                  13366  1 libps2
serio                  10721  6 serio_raw,atkbd,i8042,psmouse

Last edited by willardthor (2014-05-21 21:35:13)

willardthor · 2014-03-05 23:53:45

Progress; I can adjust screen brightness again (just not through ACPI).

Following this, I added

Option "Backlight"     "intel_backlight"

under the "Device" section (which uses the Intel driver) of my xorg.conf file. Here's the full content of my xorg.conf file.

$ cat /etc/X11/xorg.conf.d/10-monitor.conf
Section "Monitor"
    Identifier             "Monitor0"
    Option "DPMS"          "true"
EndSection

Section "Device"
    Identifier             "Device0"
    Driver                 "intel"
    Option "Backlight"     "intel_backlight"
EndSection

Section "Screen"
    Identifier             "Screen0"
    Device                 "Device0"
    Monitor                "Monitor0"
    DefaultDepth            24
    SubSection             "Display"
        Depth               24
        Modes              "1024x600_60.00"
    EndSubSection
EndSection

Section "ServerLayout"
    Identifier             "ServerLayout0"
    Screen      0          "Screen0" 0 0
    Option "BlankTime"     "30"
    Option "StandbyTime"   "35"
    Option "SuspendTime"   "40"
    Option "OffTime"       "45"
EndSection

I can now adjust screen brightness with the following commands.

$ xbacklight -dec 10 # brightness reduced by 10% of full brightness
$ xbacklight -inc 10 # brightness increased by 10% of full brightness

(reducing brightness to 0% of full brightness makes your display pitch-black, by the way; make sure the increasing brightness command is available to you).

However, I still cannot get ACPI to adjust screen brightness. I have tried various combinations of kernel options I have seen during Google searches, including

acpi_backlight=vendor

which I think makes sense, with and without the frequently accompanying

acpi_osi=Linux

as well as the combination

acpi_backlight=video

and

video.use_native_backlight=1

without success.

Any suggestions?

In case or relevance,

$ ls -l /sys/class/backlight/
total 0
lrwxrwxrwx 1 root root 0 Mar  6 00:28 acpi_video0 -> ../../devices/pci0000:00/0000:00:02.0/backlight/acpi_video0
lrwxrwxrwx 1 root root 0 Mar  6 00:28 intel_backlight -> ../../devices/pci0000:00/0000:00:02.0/drm/card0/card0-LVDS-1/intel_backlight

djraymondnm · 2014-03-08 16:14:54

After upgrading to the 3.13 kernel from 3.12 on my laptop, I couldn't control the screen brightness via the function keys anymore as well. Downgrading to 3.12 fixed the problem. The microphone mute is also activated and cannot be de-activated by the function keys with 3.13. (My laptop is a Lenovo X230.)

Did your upgrade happen to upgrade the kernel?

willardthor · 2014-03-08 16:22:19

Yes.

$ cat /var/log/pacman.log | grep "upgraded linux" | grep "3.13.5-1"
[2014-02-24 12:25] [PACMAN] upgraded linux (3.12.9-2 -> 3.13.5-1)

The only function key that works for me is sleep (yay), but most of mine didn't work before the upgrade either.

OrangeMediumGreen · 2014-03-08 18:34:30

djraymondnm wrote:

After upgrading to the 3.13 kernel from 3.12 on my laptop, I couldn't control the screen brightness via the function keys anymore as well. Downgrading to 3.12 fixed the problem. The microphone mute is also activated and cannot be de-activated by the function keys with 3.13. (My laptop is a Lenovo X230.)

Exactly the same here (X230). There seems to have been an update to the thinkpad acpi support, so it's a lenovo specific problem.

browntown · 2014-03-10 04:27:18

my acer aspire one d257 lost fn key support for brightness, volume, mute, the numpad, and a couple others in 3.13 as well. Not that it matters, but the whole acpi_backlight=vendor business is deprecated in 3.13 forward. The linux kernel bugtracker has a couple of these problems that I'm following.

OrangeMediumGreen · 2014-03-15 13:04:02

Do you get a similar message during boot?

thinkpad_acpi: Unsupported brightness interface, please contact ibm-acpi-devel@lists.sourceforge.net

browntown · 2014-03-16 14:58:08

No I don't. It seems ibm's are the biggest culprit, but my acer has similar problems. I think they're adding specific models to the dmi table. It makes zero sense to me why acpi_video0 was added to our computers when we only have intel backlight. I'm still working on my bug in the upstream kernel bug-tracker here: https://bugzilla.kernel.org/show_bug.cgi?id=71491

Not mine, but lots of work being done on similar problem: https://bugzilla.kernel.org/show_bug.cgi?id=35622

VanillaFunk · 2014-03-16 15:03:55

As a work around for folks with function keys not adjusting brightness install xfce4-power-manager
I started using it when I used awesome and if you dont want the system tray icon you can shut it off in the preferences but it allows for fn keys to adjust brightness

willardthor · 2014-03-16 21:14:22

OrangeMediumGreen wrote:

Do you get a similar message during boot?

thinkpad_acpi: Unsupported brightness interface, please contact ibm-acpi-devel@lists.sourceforge.net

You mean by inspecting the log accessible by running this?

$ journalctl -b

I see no errors associated with brightness in logs.

***

While working on my FN volume up/down/mute keys to see if I could map their scancodes to commands manually, I noticed that pressing them produces no events whatsoever. From this, I got the impression that I need to have certain kernel modules loaded for some FN key presses to register. So I looked at this, which mention several modules, the following of which are not loaded on my machine.

eeepc-wmi
fan
eeepc-laptop

(cpufreq_ondemand mentioned in one of the URLs above is no longer a module according to this, and is enabled on my machine, although I don't see any PSTATE stuff out of dmesg).

Instead, however, my eee loads the following module.

asus_wmi

Indeed, for some desktop PC users with an Asus motherboard, the upgrade to kernel version 3.13 caused their kernel to attempt loading the eeepc-wmi module, and fail loading it.

Should I blacklist asus_wmi? Will that automagically cause eeepc-wmi and/or eeepc-laptop to be loaded, or must I configure this as per these instructions?

Last edited by willardthor (2014-03-16 21:16:17)

willardthor · 2014-03-16 21:37:13

I tried creating a config file to have eeepc-laptop loaded on startup, but lsmod shows it didn't get loaded. I checked my journal to see what went wrong:

Mar 16 22:25:12 fenrir systemd-modules-load[118]: Failed to insert 'eeepc_laptop': No such device

However, upon inspecting the journal more closely, discovered that it seems my eeepc tries to load eeepc-wmi, but fails:

Mar 16 22:25:13 fenrir kernel: asus_wmi: ASUS WMI generic driver loaded
Mar 16 22:25:13 fenrir kernel: asus_wmi: Initialization: 0x0
Mar 16 22:25:13 fenrir kernel: asus_wmi: BIOS WMI version: 0.8
Mar 16 22:25:13 fenrir kernel: asus_wmi: SFUN value: 0x0
Mar 16 22:25:13 fenrir kernel: input: Eee PC WMI hotkeys as /devices/platform/eeepc-wmi/input/input10
[...]
Mar 16 22:25:15 fenrir kernel: ACPI Error: 
Mar 16 22:25:15 fenrir kernel: [_T_0] Namespace lookup failure, AE_ALREADY_EXISTS (20131115/dswload2-330)
Mar 16 22:25:15 fenrir kernel: ACPI Exception: AE_ALREADY_EXISTS, During name lookup/catalog (20131115/psobject-222)
Mar 16 22:25:15 fenrir kernel: ACPI Error: Method parse/execution failed [\AMW0.WMBC] (Node ffff88007bb3d410), AE_ALREADY_EX
Mar 16 22:25:15 fenrir kernel: asus_wmi: Error removing rfkill notify handler \_SB.PCI0.P0P5
Mar 16 22:25:15 fenrir kernel: asus_wmi: Error removing rfkill notify handler \_SB.PCI0.P0P6
Mar 16 22:25:15 fenrir kernel: asus_wmi: Error removing rfkill notify handler \_SB.PCI0.P0P7
[...]
Mar 16 22:25:17 fenrir kernel: eeepc-wmi: probe of eeepc-wmi failed with error -5

Any ideas?

OrangeMediumGreen · 2014-03-18 08:49:26

willardthor wrote:

OrangeMediumGreen wrote:
Do you get a similar message during boot?
thinkpad_acpi: Unsupported brightness interface, please contact ibm-acpi-devel@lists.sourceforge.net
You mean by inspecting the log accessible by running this?
$ journalctl -b

Yes, for example. I used dmesg however.

tr071 · 2014-03-28 04:46:30

I have the same problem with my eee 1000H. A lot of the Fn keys stop working recently, including the 4 special keys on the top.

I can detect these fn keys in scancode using "showkey --scancodes" in console, but can not detect keycode in neither console(using "showkey --keycodes") or xorg (using "xev | grep -A2 --line-buffered '^KeyRelease' | sed -n '/keycode /s/^.*keycode $[0-9]*$.* (.*, $.*$).*$/\1 \2/p' "). These keycodes were detected before until some recent updates.

And I switching the kernel to 3.10-lts, but it did not help.

Did you find any workaround?

willardthor · 2014-03-28 14:58:56

Besides for the most crippling issue (backlight), then no, not yet. I don't have the time at the moment to debug this, so I'm waiting and hoping some kind soul who happens to have the solution at hand comes by and shares it.

I just ran

showkey --scancodes

and

showkey --keycodes

and tried fn+F5 and fn+F6 (screen backlight up and down); both commands now register key presses. I have rebooted since I last tried, so maybe the reason for the keypresses not being registered before is that I did an upgrade (possibly including a kernel update), and didn't reboot. My kernel version is 3.13.7-1.

Last edited by willardthor (2014-03-28 15:00:46)

Antoine · 2014-04-06 13:32:59

willardthor wrote:

Besides for the most crippling issue (backlight), then no, not yet. I don't have the time at the moment to debug this, so I'm waiting and hoping some kind soul who happens to have the solution at hand comes by and shares it.

Sorry to be so slow in responding. I note from the listings in your first post that you have the i915 module installed. I had the backlight problem you describe on my old Dell D630, with a GM965/GL960 controller, when I upgraded to kernel 3.14; the screen came up at its lowest light level (hurt my old eyes) and the function dim/bright keys were inoperable. I could fix the problem my adding "nomodeset" to my linux "line" in grub, but while the backlight/function-key problem was solved, the screen resolution was ugly and unacceptable. Ploughing through the long list of kernel parameters I came across this

i915.invert_brightness=
			[DRM] Invert the sense of the variable that is used to
			set the brightness of the panel backlight. Normally a
			brightness value of 0 indicates backlight switched off,
			and the maximum of the brightness value sets the backlight
			to maximum brightness. If this parameter is set to 0
			(default) and the machine requires it, or this parameter
			is set to 1, a brightness value of 0 sets the backlight
			to maximum brightness, and the maximum of the brightness
			value switches the backlight off.
			-1 -- never invert brightness
			 0 -- machine default
			 1 -- force brightness inversion

and applied it to my linux line in grub and lo-and-behold, it solved my problem. Now I have it permanently in my grub/default.

Edit: note that I set it to "1" and it worked.

Last edited by Antoine (2014-04-06 13:36:21)

Lustique · 2014-04-08 10:11:37

willardthor wrote:

I tried creating a config file to have eeepc-laptop loaded on startup, but lsmod shows it didn't get loaded. I checked my journal to see what went wrong:
Mar 16 22:25:12 fenrir systemd-modules-load[118]: Failed to insert 'eeepc_laptop': No such device
However, upon inspecting the journal more closely, discovered that it seems my eeepc tries to load eeepc-wmi, but fails:
[...]

Hi, I've got the same problem with an Asus EeePC 1015P:

[...]
Apr 08 12:03:40 arya kernel: asus_wmi: ASUS WMI generic driver loaded
Apr 08 12:03:40 arya kernel: asus_wmi: Initialization: 0x0
Apr 08 12:03:40 arya kernel: asus_wmi: BIOS WMI version: 0.8
Apr 08 12:03:40 arya kernel: asus_wmi: SFUN value: 0x0
Apr 08 12:03:40 arya kernel: input: Eee PC WMI hotkeys as /devices/platform/eeepc-wmi/input/input11
Apr 08 12:03:40 arya kernel: psmouse serio1: elantech: assuming hardware version 2 (with firmware version 0x140100)
Apr 08 12:03:40 arya kernel: psmouse serio1: elantech: Synaptics capabilities query result 0x68, 0x15, 0x0a.
Apr 08 12:03:41 arya kernel: psmouse serio1: elantech: retrying ps2 command 0xe6 (2).
Apr 08 12:03:41 arya kernel: ieee80211 phy0: rt2x00_set_rt: Info - RT chipset 3090, rev 3213 detected
Apr 08 12:03:41 arya kernel: ieee80211 phy0: rt2x00_set_rf: Info - RF chipset 0005 detected
Apr 08 12:03:41 arya systemd-udevd[139]: renamed network interface eth0 to enp1s0
Apr 08 12:03:41 arya kernel: microcode: CPU1 sig=0x106ca, pf=0x4, revision=0x107
Apr 08 12:03:41 arya kernel: platform microcode: Direct firmware load failed with error -2
Apr 08 12:03:41 arya kernel: platform microcode: Falling back to user helper
Apr 08 12:03:41 arya kernel: microcode: Microcode Update Driver: v2.00 <tigran@aivazian.fsnet.co.uk>, Peter Oruba
Apr 08 12:03:41 arya systemd[1]: Starting system-systemd\x2drfkill.slice.
Apr 08 12:03:41 arya systemd[1]: Created slice system-systemd\x2drfkill.slice.
Apr 08 12:03:41 arya systemd[1]: Starting Load/Save RF Kill Switch Status of rfkill0...
Apr 08 12:03:41 arya kernel: Non-volatile memory driver v1.3
Apr 08 12:03:41 arya kernel: ACPI Error: [_T_0] Namespace lookup failure, AE_ALREADY_EXISTS (20131115/dswload2-330)
Apr 08 12:03:41 arya kernel: ACPI Exception: AE_ALREADY_EXISTS, During name lookup/catalog (20131115/psobject-222)
Apr 08 12:03:41 arya kernel: ACPI Error: Method parse/execution failed [\AMW0.WMBC] (Node f642df30), AE_ALREADY_EXISTS (20131115/psparse-536)
Apr 08 12:03:41 arya kernel: asus_wmi: Error removing rfkill notify handler \_SB.PCI0.P0P5
Apr 08 12:03:41 arya kernel: asus_wmi: Error removing rfkill notify handler \_SB.PCI0.P0P6
Apr 08 12:03:41 arya kernel: asus_wmi: Error removing rfkill notify handler \_SB.PCI0.P0P7
Apr 08 12:03:41 arya kernel: psmouse serio1: elantech: retrying ps2 command 0xf8 (2).
Apr 08 12:03:41 arya kernel: ieee80211 phy0: Selected rate control algorithm 'minstrel_ht'
Apr 08 12:03:41 arya systemd[1]: Starting Load/Save RF Kill Switch Status of rfkill1...
Apr 08 12:03:41 arya mtp-probe[228]: checking bus 1, device 2: "/sys/devices/pci0000:00/0000:00:1d.7/usb1/1-6"
Apr 08 12:03:41 arya mtp-probe[228]: bus: 1, device: 2 was not an MTP device
Apr 08 12:03:42 arya kernel: psmouse serio1: elantech: retrying ps2 command 0xf8 (1).
Apr 08 12:03:42 arya systemd[1]: Started Load/Save RF Kill Switch Status of rfkill0.
Apr 08 12:03:42 arya systemd-udevd[145]: renamed network interface wlan0 to wlp2s0
Apr 08 12:03:42 arya kernel: ACPI: 
Apr 08 12:03:42 arya kernel: Marking method WMBC as Serialized because of AE_ALREADY_EXISTS error
Apr 08 12:03:42 arya systemd[1]: Started Load/Save RF Kill Switch Status of rfkill1.
Apr 08 12:03:42 arya kernel: eeepc-wmi: probe of eeepc-wmi failed with error -5
[..]

My kernel is 3.13.8-1 from [core].

Any hints on how to deal with this are highly appreciated.

kevku · 2014-04-10 07:38:24

on xps m1330 with GMA965 kernel 3.14 i915.invert_brightness=1 fixed this

Last edited by kevku (2014-04-10 07:40:44)

digitalis · 2014-04-13 19:50:33

Confirmed that kernel parameter solve the issue for Dell D830.
Thank you for very useful tip.

OlaffTheGreat · 2014-04-18 08:21:36

Hi guys, very interesting post!
I do also have issues with acpi on a 1000HE. Brightness is one of the few functions that works.

I followed the wiki to set up laptop-mode.
However, the indicated painformations are not accurate anymore.
The path to the brightness device is not correct: /sys/devices/virtual/backlight/eeepc/brightness.

When I rebooted, I had errors messages about brightness and asus_wmi rfkill.
But changing brightness through fn key was still available.

So I checked paths including "brightness" (with find), and found this path :

/sys/devices/pci0000:00/0000:00:02.0/backlight/acpi_video0/brightness

I added this one into my /etc/laptop-mode/conf.d/lcd-brightness.conf.
It had the effect to clear the error brightness error messages,
however I still get this on boot: asus_wmi: Error removing rfkill notify handler.

SpeedGhost · 2014-04-19 01:53:37

I don't have any of the models of laptop listed here but using "acpi_osi=" fixed my backlight problems on a different Asus laptop.

kmiernik · 2014-04-20 17:35:07

I confirm this issue for Asus 1005P with kernel 3.14.1-1. The proposed "acpi_osi" and "invert_brightness" solutions did not help much. I used to have full scale of brightness: from almost completely dark to a very bright. Now after the brightness keys are pressed the ordering is more or less random and the states are in range of approximately 70% to 100% of the full brightness.

I found the following problematic lines in journalctl -b

Apr 20 19:02:20 X kernel: ACPI Warning: SystemIO range 0x00000828-0x0000082f conflicts with OpRegion 0
Apr 20 19:02:20 X kernel: ACPI Warning: SystemIO range 0x00000828-0x0000082f conflicts with OpRegion 0
Apr 20 19:02:20 X kernel: ACPI: If an ACPI driver is available for this device, you should use it inst
Apr 20 19:02:20 X kernel: ACPI Warning: SystemIO range 0x000004b0-0x000004bf conflicts with OpRegion 0
Apr 20 19:02:20 X kernel: ACPI: If an ACPI driver is available for this device, you should use it inst
Apr 20 19:02:20 X kernel: ACPI Warning: SystemIO range 0x00000480-0x000004af conflicts with OpRegion 0
Apr 20 19:02:20 X kernel: ACPI: If an ACPI driver is available for this device, you should use it inst
Apr 20 19:02:20 X kernel: lpc_ich: Resource conflict(s) found affecting gpio_ich
Apr 20 19:02:20 X kernel: microcode: CPU0 sig=0x106ca, pf=0x4, revision=0x107
Apr 20 19:02:20 X kernel: cfg80211: Calling CRDA to update world regulatory domain
Apr 20 19:02:20 X kernel: asus_wmi: ASUS WMI generic driver loaded
Apr 20 19:02:20 X kernel: asus_wmi: Initialization: 0x0
Apr 20 19:02:20 X kernel: asus_wmi: BIOS WMI version: 0.6
Apr 20 19:02:20 X kernel: asus_wmi: SFUN value: 0x0
Apr 20 19:02:20 X kernel: microcode: CPU1 sig=0x106ca, pf=0x4, revision=0x107
Apr 20 19:02:20 X kernel: microcode: Microcode Update Driver: v2.00 <tigran@aivazian.fsnet.co.uk>, Pet
Apr 20 19:02:20 X kernel: input: Eee PC WMI hotkeys as /devices/platform/eeepc-wmi/input/input7
Apr 20 19:02:20 X kernel: iTCO_vendor_support: vendor-support=0
Apr 20 19:02:20 X kernel: iTCO_wdt: Intel TCO WatchDog Timer Driver v1.10
Apr 20 19:02:20 X kernel: iTCO_wdt: Found a NM10 TCO device (Version=2, TCOBASE=0x0860)
Apr 20 19:02:20 X kernel: iTCO_wdt: initialized. heartbeat=30 sec (nowayout=0)
Apr 20 19:02:20 X kernel: asus_wmi: Backlight controlled by ACPI video driver
Apr 20 19:02:20 X kernel: ACPI Warning: SystemIO range 0x00000400-0x0000041f conflicts with OpRegion 0
Apr 20 19:02:20 X kernel: ACPI Warning: SystemIO range 0x00000400-0x0000041f conflicts with OpRegion 0
Apr 20 19:02:20 X kernel: ACPI: If an ACPI driver is available for this device, you should

fusca · 2014-04-24 22:12:55

Hi...

I have the same problem on Dell XPS M1330 with Kernel 3.14.1.

"Linux dellxps 3.14.1-1-ARCH #1 SMP PREEMPT Mon Apr 14 20:40:47 CEST 2014 x86_64 GNU/Linux"

I've followed the discussion https://bugzilla.kernel.org/show_bug.cgi?id=62941 and it resolved my brightness problem:

"For list:
$ ls /sys/class/backlight

For echo:
Suppose acpi_video0 is there, then:
1 check max_brightness value by
$ cat /sys/class/backlight/acpi_video0/max_brightness
20
2 check current brightness level by
$ cat /sys/calss/backlight/acpi_video0/brightness
10
3 set different levels
# echo 5 > /sys/class/backlight/acpi_video0/brightness
# echo 10 > /sys/class/backlight/acpi_video0/brightness
See if brightness level changes.

You can test other interfaces under /sys/class/backlight too."

Thanks.

djraymondnm · 2014-04-27 15:04:11

Here is a low-level hack in the form of a shell script similar to the previous post to solve the backlight problem on my Thinkpad X230:

#!/bin/sh
#
# brightness.sh -- Set brightness control in 3.14 kernel since the
# keyboard function buttons are now broken.
#
if test $# != 1
then
    echo "Usage: brightness.sh num (1 <= num <= 10)"
else
    num=$1
    if test ${num} -lt 1
    then
	num=1
    fi
    if test ${num} -gt 10
    then
	num=10
    fi

    xnum=$((${num}*400 + 400))
    echo $xnum > /sys/class/backlight/intel_backlight/brightness
fi

No special kernel flag or module (at least that isn't loaded by default) is needed to enable this. The script may work for any Intel graphics chipset, though the scaling needed for "xnum" may differ -- a matter of trial and error! Max brightness is attained with xnum about 4400 on my machine.
This script of course has to be run as root. I access it via suid from normal user status -- probably safe enough on my laptop as I'm the only one using it.

Stevearch · 2014-05-01 10:53:12

Im not sure if this will help you but i had a simmilar problem on my Dell D630. It would register my FN key press but the brightness would just stay at the lowest settings. (even when KDE thought it was at 100%) If i went in and manually changed my /sys/class/backlight/intel_backlight/brightness setting and changed it to 254000 it would go to max setting and then i could control my brightness properly with the FN keys. On every boot these settings would be lost though.

My work around:

Create a Udev rule like in the Wiki: Wiki article

Remember to mask your backlight services!

Steve wrote:

sudo systemctl mask systemd-backlight@backlight:acpi_video0.service

Change 'acpi_video0' to what ever is loaded by systemd

To view the loaded backlight .services do:

Steve wrote:

systemctl | grep backlight

This might not work for you but give it a go!

Let me know if you get stuck.

Last edited by Stevearch (2014-05-01 10:53:45)

willardthor · 2014-05-21 21:34:35

Thank you all for the great advice. I did a semi-long-pending upgrade, and now screen brightness control works again out-of-the-box. So I am marking this as solved. If you wants me to provide information to help pin down what the source of the solution was, or to keep this thread unsolved for whoever else has not had this issue solved yet, let me know.

Last edited by willardthor (2014-05-21 21:40:18)

Arch Linux

#1 2014-03-04 20:52:03

[solved] ACPI cannot control screen brightness anymore

#2 2014-03-05 23:53:45

Re: [solved] ACPI cannot control screen brightness anymore

#3 2014-03-08 16:14:54

Re: [solved] ACPI cannot control screen brightness anymore

#4 2014-03-08 16:22:19

Re: [solved] ACPI cannot control screen brightness anymore

#5 2014-03-08 18:34:30

Re: [solved] ACPI cannot control screen brightness anymore

#6 2014-03-10 04:27:18

Re: [solved] ACPI cannot control screen brightness anymore

#7 2014-03-15 13:04:02

Re: [solved] ACPI cannot control screen brightness anymore

#8 2014-03-16 14:58:08

Re: [solved] ACPI cannot control screen brightness anymore

#9 2014-03-16 15:03:55

Re: [solved] ACPI cannot control screen brightness anymore

#10 2014-03-16 21:14:22

Re: [solved] ACPI cannot control screen brightness anymore

#11 2014-03-16 21:37:13

Re: [solved] ACPI cannot control screen brightness anymore

#12 2014-03-18 08:49:26

Re: [solved] ACPI cannot control screen brightness anymore

#13 2014-03-28 04:46:30

Re: [solved] ACPI cannot control screen brightness anymore

#14 2014-03-28 14:58:56

Re: [solved] ACPI cannot control screen brightness anymore

#15 2014-04-06 13:32:59

Re: [solved] ACPI cannot control screen brightness anymore

#16 2014-04-08 10:11:37

Re: [solved] ACPI cannot control screen brightness anymore

#17 2014-04-10 07:38:24

Re: [solved] ACPI cannot control screen brightness anymore

#18 2014-04-13 19:50:33

Re: [solved] ACPI cannot control screen brightness anymore

#19 2014-04-18 08:21:36

Re: [solved] ACPI cannot control screen brightness anymore

#20 2014-04-19 01:53:37

Re: [solved] ACPI cannot control screen brightness anymore

#21 2014-04-20 17:35:07

Re: [solved] ACPI cannot control screen brightness anymore

#22 2014-04-24 22:12:55

Re: [solved] ACPI cannot control screen brightness anymore

#23 2014-04-27 15:04:11

Re: [solved] ACPI cannot control screen brightness anymore

#24 2014-05-01 10:53:12

Re: [solved] ACPI cannot control screen brightness anymore

#25 2014-05-21 21:34:35

Re: [solved] ACPI cannot control screen brightness anymore

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