Brightness hot-keys don't work on Samsung NC10

[Alex Moldovan]

Binary package hint: gnome-power-manager

Brightness hot-keys don't work on Samsung NC10 and the brightness doesn't change. The other keys work fine.

ProblemType: Bug
Architecture: i386
Date: Wed Mar 17 11:37:18 2010
DistroRelease: Ubuntu 10.04
GnomeSessionIdleInhibited: No
GnomeSessionInhibitors: None
GnomeSessionSuspendInhibited: No
InstallationMedia: Ubuntu 10.04 "Lucid Lynx" - Beta i386 (20100317)
MachineType: SAMSUNG ELECTRONICS CO., LTD. NC10
Package: gnome-power-manager 2.29.91-0ubuntu6
ProcCmdLine: BOOT_IMAGE=/boot/vmlinuz-2.6.32-16-generic root=UUID=882801f5-0538-4f08-9c33-7c838754f405 ro quiet splash initcall_debug
ProcEnviron:
 LANG=en_US.UTF-8
 SHELL=/bin/bash
ProcVersionSignature: Ubuntu 2.6.32-16.25-generic
SourcePackage: gnome-power-manager
Uname: Linux 2.6.32-16-generic i686
dmi.bios.date: 12/11/2008
dmi.bios.vendor: Phoenix Technologies Ltd.
dmi.bios.version: 04CA.MP00.20081211.KTW
dmi.board.name: NC10
dmi.board.vendor: SAMSUNG ELECTRONICS CO., LTD.
dmi.board.version: Not Applicable
dmi.chassis.asset.tag: No Asset Tag
dmi.chassis.type: 10
dmi.chassis.vendor: SAMSUNG ELECTRONICS CO., LTD.
dmi.chassis.version: N/A
dmi.modalias: dmi:bvnPhoenixTechnologiesLtd.:bvr04CA.MP00.20081211.KTW:bd12/11/2008:svnSAMSUNGELECTRONICSCO.,LTD.:pnNC10:pvrNotApplicable:rvnSAMSUNGELECTRONICSCO.,LTD.:rnNC10:rvrNotApplicable:cvnSAMSUNGELECTRONICSCO.,LTD.:ct10:cvrN/A:
dmi.product.name: NC10
dmi.product.version: Not Applicable
dmi.sys.vendor: SAMSUNG ELECTRONICS CO., LTD.

[Alex Moldovan (alexmoldovan)]

Update: The Fn+F9 keys that enables or disables the Wifi doesn't work either.
Tested with Linux 201002-5346 2.6.32-19-generic #28-Ubuntu SMP Wed Mar 31 17:46:20 UTC 2010 i686 GNU/Linux.

[Andreas Fonferek (omnibrain)]

It is also the case in Xubuntu 10.04 beta. It only shows The Window with the bar, but no change in brightness occurs. The bar is also uneffected and remains half filled.

[Chase Douglas (chasedouglas)]

I need someone to help me debug this. Please do the following:

$ /lib/udev/findkeyboards

You'll see something like "USB keyboard: input/event5". We are interested in the "input/event#" part. Next:

$ sudo /lib/udev/keymap -i /dev/input/event#

Where # is the number determined from findkeyboards. Press all the keys that are not working correctly once. You should see lines like "scan code: 0x7000E key code: volumeup". Copy and paste each line here, with a note on what each key code *should* have registered as. For example, if the brightness key was showing as volume up like above, this should be pasted here:

scan code: 0x7000E key code: volumeup (should be brightness up)

With this information I should be able to determine what is going wrong.

Thanks

[Alex Moldovan (alexmoldovan)]

I tested all the keys, and the ones that don't work are the brightness and the wifi keys. It seems like the keys are registered correctly. It looks like there's nothing wrong with the key assignment. Here's what I've found:

$ /lib/udev/findkeyboards
$ AT keyboard: input/event5

scan code: 0x88 key code: brightnessup
scan code: 0x89 key code: brightnessdown
scan code: 0x86 key code: wlan

[Chase Douglas (chasedouglas)]

Please do the following:

$ killall gnome-power-manager
$ gnome-power-manager --verbose &> gpm.log

Press each of the broken keys, then ctrl+c to kill it

$ gnome-power-manager &

Then upload the gpm.log file to this bug.

Thanks

[Chase Douglas (chasedouglas)]

Now I need the output of lshal. On my macbook, I have a computer_backlight udi with laptop_panel properties. One of the two gpm backlight mechanisms uses hal, and it only works if it can find a udi with laptop_panel props.

Thanks

[Chase Douglas (chasedouglas)]

According to bug 337370, there seem to be some issues with older bioses and backlight on the NC10. Can you check whether you are running the latest bios?

Thanks

[Andreas Fonferek (omnibrain)]

I run the latest BIOS (11CA 15.09.2009) on my NC10. In the BIOS Setup I set the "Brightness Mode Control" to "User Control".
I use Xubuntu 10.04. Installed the Beta updated every time.

scan code: 0x88 key code: brightnessup
scan code: 0x89 key code: brightnessdown
scan code: 0x86 key code: wlan

Pressing the wlan key: Nothing happens
Pressing brightnessup or brightnessdown: The Window on reght high right corner with the Sun and the brightness bar appears. But pressing the keys neither changes the bar nor the brightness.

Can't do the gpm.log thing, because on Xubuntu there is not gnome-power.manager.

[Andreas Fonferek (omnibrain)]

Ok, in BIOS Setup I changed the "Brightness Mode Control" to "Auto" but that doesn't help.

[Chase Douglas (chasedouglas)]

This issue is definitely a bios/kernel/driver issue. Do we know if this used to work in previous releases of Ubuntu?

Thanks

[Andreas Fonferek (omnibrain)]

I can only speak for the brightness buttons.
It worked like a charm in 9.04 even with the old BIOS.
In 9.10 nothing happened. After upgrading to the latest BIOS the keys functioned again. But I had some difficulties, when running with the battery. The brightness decreased itself after a while idleing, but didn't increase back after key/mouseactions. I had to adjust it manually.

[Alex Moldovan (alexmoldovan)]

I've tested it with 9.10 and 9.04.In 9.10 the keys don't work but they do in 9.04.

[Andreas Fonferek (omnibrain)]

I updatet the system to the latest (final). Adjustement of brightness still doesn't work. But now even the window in the right corner doesn't appear anymore.

[Chase Douglas (chasedouglas)]

It would be helpful to have a trace of the kernel backlight functions. Please run the following:

$ sudo sh -c "echo '*backlight*' > /sys/kernel/debug/tracing/set_ftrace_filter"
$ sudo sh -c "echo function_graph > /sys/kernel/debug/tracing/current_tracer"
$ sudo sh -c "echo 1 > /sys/kernel/debug/tracing/tracing_enbled"
$ sudo sh -c "echo 1 > /sys/kernel/debug/tracing/tracing_on"

Then hit one of the backlight buttons. Now, upload the file /sys/kernel/debug/tracing/trace.

Thanks

[Andreas Fonferek (omnibrain)]

Attached is the file you requested. I pressed the decrease backlight key.

[Chase Douglas (chasedouglas)]

Based on the trace, it looks like the kernel is not getting any acpi backlight decrease signals, but somewhere the key is being processed. I'll need to investigate this some more.

[McGivrer (frederic-delorme)]

On My Samsung R580 i have the same issue: if you let the mouse on the brightness applet, a tooltip saying "Unable to get Screen brightness" appear (the real message is a french one "Impossible d'obtenir la luminosité de l'écran".
So is it an ACPI issue ? see hal.txt a resulting lshal output file.

[McGivrer (frederic-delorme)]

forgot to attach extract of gnome-power-management output in verbose mode while Pressing Fn+UP & FN+Dwn keys.

[Kishore (kitts)]

Here on Kubuntu 10.04, Pressing the brightness keys only pops up the brightness control level display which does not move and neither the brightness actually change. However, i can change the brightness by moving the brightness slider in the plasma battery applet.

[papukaija (papukaija)]

The minimum required BIOS version is 11Ca because "brightness controls require BIOS 11CA due to the new graphics system. " as seen at https://help.ubuntu.com/community/NC10#Karmic%209.10

[papukaija (papukaija)]

Please note that the issue about completely enabling/disabling baclight (eg screen on/off) with Fn-F5 button is tracked at bug 296489.

[papukaija (papukaija)]

Closing since the brightness control itself works starting with Karmic as long as you've upgraded your BIOS to at least v.11CA. Please see the link in #23 for alternative solutions if you don't want to upgrade your BIOS.

However, there are related issues which don't affect the brightness control itself: Oneiric users will find following bug 810093 useful. The issue about completely enabling/disabling baclight (eg screen on/off) with Fn-F5 button is tracked at bug 296489.