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Zaku140

Member

Registered: 2015-08-14

Posts: 31

Thinkpad_acpi unsupported brightness interface

During startup and shutdown process grub outputs:

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

I am able to adjust my brightness with keys but adjusting it is slow. When I press the brightness key it takes about 2 seconds to actually increase or decrease.
To find problems I did:

dmesg | grep thinpad_acpi

I get this output:

[    5.195818] thinkpad_acpi: ThinkPad ACPI Extras v0.25
[    5.195822] thinkpad_acpi: http://ibm-acpi.sf.net/
[    5.195825] thinkpad_acpi: ThinkPad BIOS JBET50WW (1.15 ), EC unknown
[    5.195828] thinkpad_acpi: Lenovo ThinkPad T450s, model 20BXCTO1WW
[    5.196490] thinkpad_acpi: Unsupported brightness interface, please contact ibm-acpi-devel@lists.sourceforge.net
[    5.197767] thinkpad_acpi: radio switch found; radios are enabled
[    5.197848] thinkpad_acpi: This ThinkPad has standard ACPI backlight brightness control, supported by the ACPI video driver
[    5.197849] thinkpad_acpi: Disabling thinkpad-acpi brightness events by default...
[    5.198972] thinkpad_acpi: rfkill switch tpacpi_bluetooth_sw: radio is unblocked
[    5.200936] input: ThinkPad Extra Buttons as /devices/platform/thinkpad_acpi/input/input7

I don't understand why brightness is not supported but I am still able to adjust it. I also don't know why its disabling brightness events. I'm guessing enabling thinkpad_acpi would stop the error message but how? And would this solve my problem with adjusting the brightness? I have a Thinkpad T450s. I searched the wiki and forums but I couldn't find anything related to my problem.

martinmr

Member

Registered: 2015-08-14

Posts: 4

Re: Thinkpad_acpi unsupported brightness interface

I just got a W541 today and I see the same message during boot. I still can change the brightness just fine. I don't think there's anything to worry about.

Zaku140

Member

Registered: 2015-08-14

Posts: 31

Re: Thinkpad_acpi unsupported brightness interface

When you adjust the brightness is it smooth like adjusting the volume? Or is it slow? Thank you. I'll wait to see if a few more people are having this problem too before I mark this thread resolved.

ewaller

Administrator

From: Pasadena, CA

Registered: 2009-07-13

Posts: 20,490

Re: Thinkpad_acpi unsupported brightness interface

What are the contents of /sys/class/backlight ?

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Zaku140

Member

Registered: 2015-08-14

Posts: 31

Re: Thinkpad_acpi unsupported brightness interface

I have intel_backlight inside that directory. I should have given this information in the original post sorry about that.

ewaller

Administrator

From: Pasadena, CA

Registered: 2009-07-13

Posts: 20,490

Re: Thinkpad_acpi unsupported brightness interface

No worries.  I was mostly checking to ensure there were not two.  On my system I get intel and acpi backlight.  Unless I blacklist acpi backlight, there seem to be two mechanisms that are wrestle over the control.  One will change it, and the other will change it back

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dice

Member

From: Germany

Registered: 2014-02-10

Posts: 413

Re: Thinkpad_acpi unsupported brightness interface

I see this message during boot, too. I got an E540. But it works fine though.
I guess

[    5.197848] thinkpad_acpi: This ThinkPad has standard ACPI backlight brightness control, supported by the ACPI video driver

means there is just no need for a specific handling through thinkpad-acpi as it works with standard acpi driver.

Obviously this doesn't solve your lag when changing brightness but it explains why it (somehow) works in the first place.
What DE/WM are you using? Maybe there is some hook which introduces delays such as a nice fancy overlay showing the percentage or something

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Zaku140

Member

Registered: 2015-08-14

Posts: 31

Re: Thinkpad_acpi unsupported brightness interface

I'm using KDE Plasma 5. I did notice when I am in /sys/class/backlight/intel_backlight/ I see the directories:

device power  subsystem

When I open device I see the following directories:

device   i2c-7    intel_backlight    power   subsystem

When I go into intel_backlight it takes me back to these directories again:

device  power subsystem

Its just an endless loop of going back to the same directories. Is there something overlapping?

Zaku140

Member

Registered: 2015-08-14

Posts: 31

Re: Thinkpad_acpi unsupported brightness interface

[Update]

okay so I had some free time to work on this problem. Inside the power directory I noticed that "runtime_enabled" is disabled and runtime_status is unsupported. I am assuming that I should enable "runtime" but how do I enable this?

cfr

Member

From: Cymru

Registered: 2011-11-27

Posts: 7,168

Re: Thinkpad_acpi unsupported brightness interface

I have 2 directories in /sys/class/backlight. However, they don't fight: one actually does something; the other does nothing. I assume this is because one is disabled even though it reflects the current status. I get this in the journal:

kernel: thinkpad_acpi: This ThinkPad has standard ACPI backlight brightness control, supported by the ACPI video driver

...

kernel: thinkpad_acpi: Standard ACPI backlight interface available, not loading native one

I'm also using Plasma 5 and, although it is horrendously slow in other cases, I just tested and my brightness keys work instantly. (Normally, I don't touch them as I have the brightness automatically adjusted.)

However, I have never been able to control brightness via /sys/class/backlight/intel_backlight - only ever via /sys/class/backlight/acpi_video0. However, I've assumed this is because the 'native' driver is disabled automatically in favour of ACPI's.

The endless loops are normal as far as I know. At least, my /sys has always been full of them and (almost) everything works just fine.

[Update]

okay so I had some free time to work on this problem. Inside the power directory I noticed that "runtime_enabled" is disabled and runtime_status is unsupported. I am assuming that I should enable "runtime" but how do I enable this?

Maybe a missing driver? That is ACPI doesn't support it and you don't have the relevant stuff installed for control via the native interface?

Last edited by cfr (2015-08-29 22:46:35)

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kaptoxic

Member

Registered: 2013-07-31

Posts: 21

Re: Thinkpad_acpi unsupported brightness interface

I keep getting:

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

although I can control brightness with function keys (I am using t450s).

SaltySockets

Member

Registered: 2015-10-10

Posts: 22

Re: Thinkpad_acpi unsupported brightness interface

I get that error too but the backlight adjustments works perfectly.
I wish the driver shut up if it notices that the backlight is controlled by other means (which it clearly notices, it even says so in the log).

I too have a T450s.

sawa

Member

Registered: 2015-03-22

Posts: 15

Re: Thinkpad_acpi unsupported brightness interface

I get the same message during boot, but i can control brightness with my function keys perfectly.
I am using thinkpad X250,
i guess all thinkpad are getting these problem(?)
I am going to take a look to the latest kernel.

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MisterChoc

Member

Registered: 2013-02-17

Posts: 74

Re: Thinkpad_acpi unsupported brightness interface

I'll just join the club. T450s

gilgamezh

Member

From: CABA, Argentina

Registered: 2011-05-08

Posts: 4

Website

Re: Thinkpad_acpi unsupported brightness interface

same here on a x250

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Ryoushiki

Member

Registered: 2015-11-18

Posts: 1

Re: Thinkpad_acpi unsupported brightness interface

Same here on s3-s431.

I also found that the maximum brightness is not as light as in windows. Did anyone know what is the possible cause?

Zaku140

Member

Registered: 2015-08-14

Posts: 31

Re: Thinkpad_acpi unsupported brightness interface

Same here on s3-s431.

I also found that the maximum brightness is not as light as in windows. Did anyone know what is the possible cause?

Unfortunately not, I still haven't found a cause yet

TheDemz

Member

Registered: 2015-08-22

Posts: 12

Re: Thinkpad_acpi unsupported brightness interface

Thinkpad T430s

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

System:  Kernel: 4.1.17-1-lts x86_64 (64 bit gcc: 5.3.0)
           Desktop: Gnome 3.18.3 (Gtk 3.18.7) info: gnome-shell dm: gdm Distro: Arch Linux
CPU:       Dual core Intel Core i5-3320M (-HT-MCP-) cache: 3072 KB
           flags: (lm nx sse sse2 sse3 sse4_1 sse4_2 ssse3 vmx) bmips: 10375
           clock speeds: min/max: 1200/3300 MHz 1: 1397 MHz 2: 1199 MHz 3: 1204 MHz 4: 1267 MHz
Graphics:  Card: Intel 3rd Gen Core processor Graphics Controller bus-ID: 00:02.0 chip-ID: 8086:0166
           Display Server: X.Org 1.18.1 drivers: intel (unloaded: fbdev,vesa) Resolution: 1600x900@60.00hz
           GLX Renderer: Gallium 0.4 on llvmpipe (LLVM 3.7, 256 bits)
           GLX Version: 3.0 Mesa 11.1.2 Direct Rendering: Yes

ymihc

Member

Registered: 2016-02-03

Posts: 21

Re: Thinkpad_acpi unsupported brightness interface

I added

intel_agp i915

to the MODULES section in my mkinitcpio.conf (and regenerated it) to enable early KMS - after that the message

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

disappeared during boot and all works fine with my Thinkpad X250.

More information regarding KMS can be found in the wiki: https://wiki.archlinux.org/index.php/in … _early_KMS and https://wiki.archlinux.org/index.php/Ke … de_setting.

Last edited by ymihc (2016-02-17 12:44:25)

TheDemz

Member

Registered: 2015-08-22

Posts: 12

Re: Thinkpad_acpi unsupported brightness interface

tried the

intel_agp i915

dmesg

[    1.999748] thinkpad_acpi: ThinkPad ACPI Extras v0.25
[    1.999751] thinkpad_acpi: http://ibm-acpi.sf.net/
[    1.999752] thinkpad_acpi: ThinkPad BIOS G7ETA3WW (2.63 ), EC unknown
[    1.999754] thinkpad_acpi: Lenovo ThinkPad T430s, model 23561U9
[    2.005493] thinkpad_acpi: Unsupported brightness interface, please contact ibm-acpi-devel@lists.sourceforge.net

Still get the error message, everything seems to work fine, just annoying error message.

lifeafter2am

Member

From: 127.0.0.1

Registered: 2009-06-10

Posts: 1,332

Re: Thinkpad_acpi unsupported brightness interface

Thinkpad x240.

I've tried a variety of things including the

intel_agp i915

to the modules, and also seting this in the grub boot parameters that I found  on a Debian page for my laptop

GRUB_CMDLINE_LINUX_DEFAULT="quiet acpi_osi=!Windows2012 acpi_backlight=vendor"

And tons of combinations of the above. No matter what I cannot control my backlight interface at all with the hotkeys. I have to use 'xbacklight' from the command line to make any changes.

Super annoying for an otherwise awesome laptop.

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