Closed titonbarua closed 7 years ago
Also, the policykit action file found in /usr/share/polkit-1/actions/org.xfce.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>XFCE Power Manager</vendor>
<vendor_url>http://goodies.xfce.org/projects/applications/xfce4-power-manager</vendor_url>
<icon_name>battery</icon_name>
<action id="org.xfce.power.backlight-helper">
<description>Modify the laptop display brightness</description>
<message>Authentication is required to modify the laptop display 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/sbin/xfpm-power-backlight-helper</annotate>
</action>
<action id="org.xfce.power.xfce4-pm-helper">
<description>Suspend or hibernate the system</description>
<message>Authentication is required to place the system in suspend or hibernate mode</message>
<defaults>
<allow_any>auth_admin</allow_any>
<allow_inactive>auth_admin</allow_inactive>
<allow_active>yes</allow_active>
</defaults>
<annotate key="org.freedesktop.policykit.exec.path">/usr/sbin/xfce4-pm-helper</annotate>
</action>
</policyconfig>
Previous discussion: #148, #176. I think @coolstar had said it was a bug in his firmware which he intended to fix, but I guess he can't fix it without compromising Windows compatibility..?
We don't have confirmation yet that the workaround for CoolStar firmware on Broadwell work fine/don't interfere with factory/other firmware on Broadwell, but we do know that the workaround causes problems for all firmware on Haswell. So we're waiting for data before deciding how to proceed.
Thank you @reynhout . I should have searched harder in the existing issues.
@titonbarua There's good info in the other issues, but your investigation is very helpful too. We didn't know whether the problem was possible to work around in the OS (vs kernel params or firmware)...but you've demonstrated that it is, which is awesome. Not sure what the eventual solution will be, but it definitely opens up possibilities. So thank you! :)
@reynhout , i feel honored! :)
Finally, I've tried the solution suggested by @coolstar and it worked perfectly. I am listing the steps in a friendly manner to help anyone bumping this thread:
gksu mousepad /etc/default/grub
.GRUB_CMDLINE_LINUX_DEFAULT=
.acpi_backlight=vendor
to the end of the line, inside the double quoted text. The line for my specific chromebook ( dell chromebook 13, 2015, core i3), after modification: GRUB_CMDLINE_LINUX_DEFAULT="quiet splash tpm_tis.interrupts=0 i915.enable_ips=0 acpi_backlight=vendor"
gksu update-grub
. Restart after the command finishes.After this, I was able to modify brightness with both the plugin slider and keyboard controls.
This should be resolved in later ISOs and current kernels. Please re-open if the issue persists.
Issue:
Screen brightness adjustment does not work. The brightness keys work as intended. The notification of screen brightness also change as usual. But no actual change takes place. Brightness slider on the panel plugin was also useless. I've done some research regarding it. I think the problem might be related to permission issues of
xfpm-power-backlight-helper
program.xfpm-power-backlight-helper works perfectly
Trying to execute
pkexec xfpm-power-backlight-helper --set-brightness 500
displays policykit permission dialogue, which does indeed change brightness after authorization.Brightness can be increased by directly messing in
sysfs
Brightness can be controlled by directly writing to
/sys/class/backlight/intel_backlight/
. I've written a small python3 script which can be used to change brightness. The source code is available at the bottom(in case it helps anyone).Hardware:
Distro
Contents of my
/etc/lsb-release
:xfce4-power-manager package version
1.4.3-0ubuntu1-galliumos14
Custom brightness control script
This must be run as root. Also, python3 must be installed.