'backlight 'up'' permission issue on upgrade from Precise to Trusty

[david-c]

The backlight 'up' and 'down' function keys on my Toshiba Satellite now require an admin password everytime I use them. For some reason (which I can't remember) in the distant past, I set it up to use the ctrl-F6 and ctrl-F7 key combinations rather than Fn-F6 and Fn-F7 for their control. Any ideas?

[matt_symes]

Hi


The backlight 'up' and 'down' function keys on my Toshiba Satellite now require an admin password everytime I use them. For some reason (which I can't remember) in the distant past, I set it up to use the ctrl-F6 and ctrl-F7 key combinations rather than Fn-F6 and Fn-F7 for their control. Any ideas?

Policy kit ?

What is the output of this command from the terminal ?


cat /usr/share/polkit-1/actions/org.gnome.settings-daemon.plugins.power.policy

Kind regards

[david-c]

cat /usr/share/polkit-1/actions/org.gnome.settings-daemon.plugins.power.policy
<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE policyconfig PUBLIC
"-//freedesktop//DTD PolicyKit Policy Configuration 1.0//EN"
"http://www.freedesktop.org/standards/PolicyKit/1.0/policyconfig.dtd">
<policyconfig>



<vendor>GNOME Settings Daemon</vendor>
<vendor_url>http://git.gnome.org/browse/gnome-settings-daemon</vendor_url>
<icon_name>battery</icon_name>

<action id="org.gnome.settings-daemon.plugins.power.backlight-helper">

<description gettext-domain="gnome-settings-daemon">Modify the laptop brightness</description>
<message gettext-domain="gnome-settings-daemon">Authentication is required to modify the laptop brightness</message>
<defaults>
<allow_any>no</allow_any>
<allow_inactive>no</allow_inactive>
<allow_active>yes</allow_active>
</defaults>
<annotate key="org.freedesktop.policykit.exec.path">/usr/lib/gnome-settings-daemon/gsd-backlight-helper</annotate>
</action>

[matt_symes]

Hi

That file looks fine to me.

What about the output of this command ?


pkaction | grep backlight

Kind regards

[david-c]

pkaction | grep backlight
com.ubuntu.unity-settings-daemon.plugins.power.backlight-helper
org.gnome.settings-daemon.plugins.power.backlight-helper

[matt_symes]

Hi

I see you're using Unity. I'm using Xubuntu so there may be some difference.

We need to look at


com.ubuntu.unity-settings-daemon.plugins.power.backlight-helper

Can you post the output of these two commands please.


pkaction --action-id com.ubuntu.unity-settings-daemon.plugins.power.backlight-helper --verbose
pkaction --action-id org.gnome.settings-daemon.plugins.power.backlight-helper --verbose

Kind regards

[david-c]

david@david-laptop:~$ pkaction --action-id com.ubuntu.unity-settings-daemon.plugins.power.backlight-helper --verbose
com.ubuntu.unity-settings-daemon.plugins.power.backlight-helper:
description: Modify the laptop brightness
message: Authentication is required to modify the laptop brightness
vendor: Unity Settings Daemon
vendor_url: http://git.gnome.org/browse/gnome-settings-daemon
icon: battery
implicit any: no
implicit inactive: no
implicit active: yes
annotation: org.freedesktop.policykit.exec.path -> /usr/lib/unity-settings-daemon/usd-backlight-helper

and


david@david-laptop:~$ pkaction --action-id org.gnome.settings-daemon.plugins.power.backlight-helper --verbose
org.gnome.settings-daemon.plugins.power.backlight-helper:
description: Modify the laptop brightness
message: Authentication is required to modify the laptop brightness
vendor: GNOME Settings Daemon
vendor_url: http://git.gnome.org/browse/gnome-settings-daemon
icon: battery
implicit any: no
implicit inactive: no
implicit active: yes
annotation: org.freedesktop.policykit.exec.path -> /usr/lib/gnome-settings-daemon/gsd-backlight-helper

[matt_symes]

Hi

I can't see much wrong there either. I am assuming the keys also use {gnome,unity} daemon though.

Does it require a password if you use the GUI and not the keys ? (I assume you can change th brightness using the GUI. It's been a while since i used Unity).

How did you remap the brightness keys in the first place ?

Out of interest, does this command require the admin password ?


pkexec /usr/lib/gnome-settings-daemon/gsd-backlight-helper --set-brightness $(( $(pkexec /usr/lib/gnome-settings-daemon/gsd-backlight-helper --get-brightness) / 2))

It should cut the screen brightness by half.

Kind regards

[david-c]

Thanks for being patient with me. Now I'm struggling! My knowledge of Ubuntu/Linux is extremely limited and very out of date. I have ADHD which results in my working memory being similar to a goldfish, lol!


I am assuming the keys also use {gnome,unity} daemon
Sorry, I have no idea...

Does it require a password if you use the GUI and not the keys ?
Is there a GUI? Where might I find it?

How did you remap the brightness keys in the first place ?
I can't remember, but I would have done a lot of Googling and following instructions blindly (I know, its a dangerous method).

...does this command require the admin password ?

david@david-laptop:~$ pkexec /usr/lib/gnome-settings-daemon/gsd-backlight-helper --set-brightness $(( $(pkexec /usr/lib/gnome-settings-daemon/gsd-backlight-helper --get-brightness) / 2))
david@david-laptop:~$
It ran silently, with no output whatever.

[matt_symes]

Hi


It ran silently, with no output whatever.

But did it reduced the screen brightness ?

Kind regards

[david-c]

Sorry,
No brightness change.

[matt_symes]

Hi


Sorry,
No brightness change.

Hmm. That's a surprise.

I don't have Unity installed on this laptop and It's been a while since i used it so i'm not sure what changes have happened to it.

I'll have a think tonight and post back tomorrow.

Someone else may also be able to step up and help.

Kind regards

[david-c]

Another observation which may help is that previous to upgrading from 12.04 to 14.04, removing the power cable used to cause the screen to dim. This no longer happens.

Tried this suggestion; Toshiba Satellite P755-S5269 keyboard backlight doesn't work (http://askubuntu.com/questions/426163/toshiba-satellite-p755-s5269-keyboard-backlight-doesnt-work), including running update-grub as root, but this edit made no difference on rebooting the system.

[david-c]

Tried using 'System Settings': 'Brightness & Lock'.
Brightness slider and 'Dim screen to save power' appear to have no affect whatsoever.

Fn-F6 (which is supposed to dim the screen) and Fn-F7 (supposed to brighten screen) both bring up a nice graphic, but fail to change the actual screen brightness.

Searching the Ubuntu Wiki revealed: DisplayBrightness (https://wiki.ubuntu.com/Kernel/Debugging/Symptom/DisplayBrightness?highlight=%28brightness%29)
This indicated two possible types of issue. I have initially chosen to explore the second of these, Kernel/Debugging/Backlight (https://wiki.ubuntu.com/Kernel/Debugging/Backlight).
Debugging information to provide in my bug report:

Executed at a terminal each of the following in order, with default Ubuntu kernel parameters:


ls /sys/class/backlight
grep -r . /proc/acpi
sudo acpidump -o acpidump.txt

Generated acpidump.txt required by following commands and included as a compressed attachment

acpixtract acpidump.txt

Generated DSDT.dat, SSDT1.dat, SSDT2.dat, and SSDT3.dat which I bundled together as attachment called acpixtract

iasl -d dsdt.dat

Generated dsdt.dsl which was huge so compressed and included as an atachment

sudo fwts > fwts

Generated a large file called 'results.log' which has been compressed and attached - the lcd brightness test successfully dimmed the screen, so a glimmer of hope!

sudo fwts method > fwts_method

Results appended to 'results.log'

dmesg | grep 'ACPI: Video' > video
sudo dmidecode > dmidecode.log
cat /proc/version > version



david@david-laptop:~$ ls /sys/class/backlight
intel_backlight toshiba


david@david-laptop:~$ grep -r . /proc/acpi
/proc/acpi/toshiba/version:driver: 0.19
/proc/acpi/toshiba/version:proc_interface: 1
/proc/acpi/toshiba/keys:hotkey_ready: 0
/proc/acpi/toshiba/keys:hotkey: 0x0000
/proc/acpi/toshiba/lcd:brightness: 7
/proc/acpi/toshiba/lcd:brightness_levels: 8
/proc/acpi/button/lid/LID/state:state: open
/proc/acpi/wakeup:Device S-state Status Sysfs node
/proc/acpi/wakeup:USB0 S3 *enabled pci:0000:00:1d.0
/proc/acpi/wakeup:USB1 S3 *enabled pci:0000:00:1d.1
/proc/acpi/wakeup:USB2 S3 *enabled pci:0000:00:1d.2
/proc/acpi/wakeup:EHC1 S3 *enabled pci:0000:00:1d.7
/proc/acpi/wakeup:USB3 S3 *enabled pci:0000:00:1a.0
/proc/acpi/wakeup:USB4 S3 *enabled pci:0000:00:1a.1
/proc/acpi/wakeup:USB5 S3 *enabled pci:0000:00:1a.2
/proc/acpi/wakeup:EHC2 S3 *enabled pci:0000:00:1a.7
/proc/acpi/wakeup:HDEF S3 *disabled pci:0000:00:1b.0
/proc/acpi/wakeup:PXS2 S4 *disabled
/proc/acpi/wakeup:RP05 S4 *disabled pci:0000:00:1c.4
/proc/acpi/wakeup:PXS5 S5 *enabled pci:0000:07:00.0
/proc/acpi/wakeup:LID S4 *enabled


david@david-laptop:~$ dmesg | grep 'ACPI: Video'
[ 2.805104] ACPI: Video Device [GFX0] (multi-head: yes rom: no post: no)


david@david-laptop:~$ cat /proc/version
Linux version 3.13.0-24-generic (buildd@roseapple) (gcc version 4.8.2 (Ubuntu 4.8.2-19ubuntu1) ) #46-Ubuntu SMP Thu Apr 10 19:08:14 UTC 2014

Lots of information, but not sure what to do with it all as yet. Hope it may be of use.

[david-c]

Continuing to work through the Ubuntu Wiki Backlight (https://wiki.ubuntu.com/Kernel/Debugging/Backlight) page.
With the kernel parameter acpi_backlight=vendor :

david@david-laptop:~$ ls /sys/class/backlight
intel_backlight toshiba

david@david-laptop:~$ ls -la /sys/class/backlight/intel_backlight/
total 0
drwxr-xr-x 3 root root 0 Apr 23 11:52 .
drwxr-xr-x 4 root root 0 Apr 23 11:52 ..
-r--r--r-- 1 root root 4096 Apr 23 12:34 actual_brightness
-rw-r--r-- 1 root root 4096 Apr 23 12:34 bl_power
-rw-r--r-- 1 root root 4096 Apr 23 12:34 brightness
lrwxrwxrwx 1 root root 0 Apr 23 12:34 device -> ../../card0-LVDS-1
-r--r--r-- 1 root root 4096 Apr 23 12:34 max_brightness
drwxr-xr-x 2 root root 0 Apr 23 12:34 power
lrwxrwxrwx 1 root root 0 Apr 23 12:34 subsystem -> ../../../../../../../class/backlight
-r--r--r-- 1 root root 4096 Apr 23 11:52 type
-rw-r--r-- 1 root root 4096 Apr 23 11:52 uevent
However,

echo 8 > /sys/class/backlight/intel_backlight/brightness
caused my laptop to crash. I tested 'echo 8' with a different (random) command (# echo 8 > /proc/sys/kernel/printk) and it did not crash.

[david-c]

Continuing from before, I have now temporarily removed the kernel parameter 'acpi_backlight=vendor' and replaced it with 'video.use_bios_initial_backlight=0':

The result was that the brightness graphic is now fully controlled by the respective function keys, whereas previously the graphic only managed a sinlge unit of brightness reduction. But, the actual screen brightness remained the same. The 'Brightness & Lock' gui had no affect on brightness whist adjusting the brightness slider, and/or swapping from mains to battery power.

[matt_symes]

Hi

I see your still trying to fix the issue.

This looks like more than just an admin/sudo issue implied by the password required for the brightness keys.

For a start, you have 2 modules loaded for the backlight by the looks of it.

Try these two commands.


echo 5 | sudo tee /sys/class/backlight/toshiba/brightness


echo 5 | sudo tee /sys/class/backlight/intel_backlight/brightness

Do either of then work and, more importantly, do any of them reduce the back light brightness ?

Try them both with and without the
acpi_backlight=vendor kernel command line.

Kind regards

[david-c]

Welcome back matt_symes,

With 'acpi_backlight=vendor'

david@david-laptop:~$ echo 5 | sudo tee /sys/class/backlight/toshiba/brightness
5

However,

echo 5 | sudo tee /sys/class/backlight/intel_backlight/brightness
killed the laptop, or at least the screen.

Without 'acpi_backlight=vendor' I am fully able to control the brightness graphics with the function key, but with no actual change in screen brightness.

david@david-laptop:~$ echo 5 | sudo tee /sys/class/backlight/toshiba/brightness
5


echo 5 | sudo tee /sys/class/backlight/intel_backlight/brightness killed the session.

I have now permanatly removed the 2 acpi kernel parameters from grub which I had inserted in the hopes of a fix.
I think I am making progress...

[david-c]

The two kernel parameters I have just removed from Grub were 'acpi_osi=linux' and 'acpi_backlight=vendor'. They were inserted based on the recommendation I refered to in #13 of this thread.