Bug 500116 - Monitor brightness settings go to 100% when monitor / system wakes up
Summary: Monitor brightness settings go to 100% when monitor / system wakes up
Status: RESOLVED DUPLICATE of bug 494408
Alias: None
Product: plasmashell
Classification: Plasma
Component: Power management & brightness (show other bugs)
Version: 6.3.0
Platform: Arch Linux Linux
: NOR normal
Target Milestone: 1.0
Assignee: Plasma Bugs List
URL:
Keywords:
Depends on:
Blocks:
 
Reported: 2025-02-15 09:55 UTC by marc
Modified: 2025-02-28 17:32 UTC (History)
14 users (show)

See Also:
Latest Commit:
Version Fixed In:
Sentry Crash Report:


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Description marc 2025-02-15 09:55:22 UTC
SUMMARY

Monitor brightness goes back to 100% (from 15%) when monitor wakes up or when system wakes up from suspend.

STEPS TO REPRODUCE
1. Allow system to suspend / monitor to sleep
2. Wake system / monitor up
3. Observe 100% of monitor brightness

OBSERVED RESULT

100% of monitor brightness

EXPECTED RESULT

Brightness should stay on configured level, in this case - 15%

SOFTWARE/OS VERSIONS

Linux/KDE Plasma: 6.12.13-1-lts
KDE Plasma Version: 6.3.0
KDE Frameworks Version: 6.10.0
Qt Version: 6.8.2

ADDITIONAL INFORMATION

```
Feb 15 10:43:35 xmg org_kde_powerdevil[3965]: org.kde.powerdevil: [DDCutilDisplay]: ddca_get_non_table_vcp_value -3007
Feb 15 10:43:35 xmg org_kde_powerdevil[3965]: dh=Display_Handle[i2c-6: fd=32], Keeping adjusted sleep multiplier 2,00 for SE_POST_WRITE or SE_POST_SAVE_SETTINGS
Feb 15 10:43:35 xmg polkit-kde-authentication-agent-1[3964]: qt.qpa.wayland: There are no outputs - creating placeholder screen
Feb 15 10:43:35 xmg kactivitymanagerd[3907]: qt.qpa.wayland: There are no outputs - creating placeholder screen
Feb 15 10:43:35 xmg kwalletd6[3661]: qt.qpa.wayland: There are no outputs - creating placeholder screen
Feb 15 10:43:35 xmg jamesdsp[4228]: qt.qpa.wayland: There are no outputs - creating placeholder screen
Feb 15 10:43:35 xmg DiscoverNotifier[4246]: qt.qpa.wayland: There are no outputs - creating placeholder screen
Feb 15 10:43:35 xmg kdeconnectd[4166]: 2025-02-15T10:43:35 qt.qpa.wayland: There are no outputs - creating placeholder screen
Feb 15 10:43:35 xmg yakuake[4236]: qt.qpa.wayland: There are no outputs - creating placeholder screen
Feb 15 10:43:35 xmg kded6[3813]: qt.qpa.wayland: There are no outputs - creating placeholder screen
Feb 15 10:43:35 xmg xdg-desktop-portal-kde[4339]: qt.qpa.wayland: There are no outputs - creating placeholder screen
Feb 15 10:43:35 xmg plasmashell[3889]: kde.plasmashell: requesting unexisting screen available rect -1
Feb 15 10:43:35 xmg plasmashell[3889]: kde.plasmashell: requesting unexisting screen available rect -1
Feb 15 10:43:35 xmg kscreenlocker_greet[28698]: qt.qpa.wayland: There are no outputs - creating placeholder screen
Feb 15 10:43:35 xmg plasmashell[3889]: kde.plasmashell: requesting unexisting screen available rect -1
Feb 15 10:43:35 xmg plasmashell[3889]: kde.plasmashell: requesting unexisting screen available rect -1
Feb 15 10:43:35 xmg org_kde_powerdevil[3965]: qt.qpa.wayland: There are no outputs - creating placeholder screen
Feb 15 10:43:35 xmg plasmashell[3889]: qt.qpa.wayland: There are no outputs - creating placeholder screen
Feb 15 10:43:35 xmg plasmashell[3889]: kf.plasma.quick: Exposed with no visual parent. Window positioning broken.
Feb 15 10:43:35 xmg plasmashell[3889]: kf.plasma.quick: Exposed with no visual parent. Window positioning broken.
Feb 15 10:43:35 xmg plasmashell[3889]: kf.plasma.quick: Exposed with no visual parent. Window positioning broken.
Feb 15 10:43:35 xmg plasmashell[3889]: kf.plasma.quick: Exposed with no visual parent. Window positioning broken.
Feb 15 10:43:35 xmg plasmashell[3889]: org.kde.applets.brightness: D-Bus action "KeyboardBrightnessControl" is not available at service "org.kde.Solid.PowerManagement"
Feb 15 10:43:36 xmg plasmashell[3889]: org.kde.applets.brightness: D-Bus action "KeyboardBrightnessControl" is not available at service "org.kde.Solid.PowerManagement"
Feb 15 10:43:37 xmg org_kde_powerdevil[3965]: dh=Display_Handle[i2c-6: fd=32], Keeping adjusted sleep multiplier 1,60 for SE_POST_WRITE or SE_POST_SAVE_SETTINGS
Feb 15 10:43:43 xmg jamesdsp[4228]: [10:43:43.758] [DBG] FilterContainer::on_link_changed::<lambda>: No app linked to our device wants to play. Unlinking our filters.

```
Comment 1 os 2025-02-15 16:07:19 UTC
Hi!

I can confirm this new bug as well. Issues started with upgrade to 6.3.
I have two monitors. The main one experiences the issue, the other one does not.

Easiest way to reproduce:
* dbus-send --session --print-reply --dest=org.kde.kglobalaccel /component/org_kde_powerdevil org.kde.kglobalaccel.Component.invokeShortcut string:'Turn Off Screen' >/dev/null
* wait until display enters power saving mode and backlight goes off
* wakup -> main display is at 100%

Operating System: Arch Linux 
KDE Plasma Version: 6.3.0
KDE Frameworks Version: 6.10.0
Qt Version: 6.8.2
Kernel Version: 6.13.2-arch1-1 (64-bit)
Graphics Platform: Wayland
Processors: 24 × AMD Ryzen 9 3900X 12-Core Processor
Memory: 62.7 GiB of RAM
Graphics Processor: Intel® Arc
Comment 2 boskobs 2025-02-16 02:27:58 UTC
(In reply to os from comment #1)
> Hi!
> 
> I can confirm this new bug as well. Issues started with upgrade to 6.3.
> I have two monitors. The main one experiences the issue, the other one does
> not.
> 
> Easiest way to reproduce:
> * dbus-send --session --print-reply --dest=org.kde.kglobalaccel
> /component/org_kde_powerdevil org.kde.kglobalaccel.Component.invokeShortcut
> string:'Turn Off Screen' >/dev/null
> * wait until display enters power saving mode and backlight goes off
> * wakup -> main display is at 100%
> 
> Operating System: Arch Linux 
> KDE Plasma Version: 6.3.0
> KDE Frameworks Version: 6.10.0
> Qt Version: 6.8.2
> Kernel Version: 6.13.2-arch1-1 (64-bit)
> Graphics Platform: Wayland
> Processors: 24 × AMD Ryzen 9 3900X 12-Core Processor
> Memory: 62.7 GiB of RAM
> Graphics Processor: Intel® Arc

I have two monitors as well, but in my case, both experience this issue.

Operating System: Fedora Linux 41
KDE Plasma Version: 6.3.0
KDE Frameworks Version: 6.10.0
Qt Version: 6.8.2
Kernel Version: 6.12.11-200.fc41.x86_64 (64-bit)
Graphics Platform: Wayland
Processors: 16 × AMD Ryzen 7 3800X 8-Core Processor
Memory: 31,2 GiB of RAM
Graphics Processor: AMD Radeon RX 5700 XT
Manufacturer: Gigabyte Technology Co., Ltd.
Product Name: B550M AORUS ELITE
Comment 3 kdebugs 2025-02-17 12:09:22 UTC
Can confirm, my main monitor has a weird behavior (goes to deep sleep immediately) where it disconnects and reconnects on wake up, it has not been an issue until 6.3. Now two of my monitor's brightness gets set to 100% on wake up. a third LG monitor is completely unaffected. I have tried downgrading powerdevil to 6.2.x, which did not help.
Comment 4 Geoffrey Chancel 2025-02-18 07:57:20 UTC
I can reproduce this on all of my computers too.
Comment 5 moylanj 2025-02-19 13:54:20 UTC
Similar behavior,

openSUSE Tumbleweed 20250217

plasma version 6.3.0

kde framework 6.11.0

Linux localhost.localdomain 6.13.2-1-default #1 SMP PREEMPT_DYNAMIC Mon Feb 10 09:00:08 UTC 2025 (306384d) x86_64 x86_64 x86_64 GNU/Linux

Ryzen 9 7900X
Intel Arc a770 LE

1x 27" 1440p connected via DP PRIMARY
1x 24" 1080p HDMI connected via external DP->HDMI adapter (builtin one is flakey it is also a DP->HDMI converter FYI) SECONDARY

Primary m,onitor on wake from sleep is ALWAYS set to 100% brightness.

Secondary monitor has been unaffected so far.

Bug did NOT appear until update to plasma 6.3.0, and has worked fine(since it appeared/offered) until said update.

Have NOT yet tested on cachyos or endeavor w/plasma 6.3 as I usually do not bother sleeping those. (Linux sleep is flakey and booting from nvme is about as fast as waking from sleep, desktop I use sleep as er... I haven't migrated the boot drive from spinning rust to nvme yet... I'm practicing my procrastination skills.)
Comment 6 Jakob Petsovits 2025-02-22 01:52:10 UTC
I can reproduce this now. It looks like the request comes from KWin directly through the corresponding "external-brightness-v1" Wayland object that is still sticking around from before the suspend/disconnect because ddcutil 2.1.4 doesn't necessarily notify us about the monitor's disappearance. The setter for 100% brightness comes in before any powerdevil-side "setBrightness()" calls are even invoked.

I haven't yet figured out why KWin resets brightness to 100% - if you check kwinoutputconfig.json after its disappearance, brightness is still at the lower (e.g. 0.15) value. It only goes up to 1 once the output gets re-enabled.

We can probably work around this by removing PowerDevil's underlying display objects if the associated KWinDisplayBrightness goes away. But it would also be good to understand where the 100% are really coming from.
Comment 7 marc 2025-02-22 16:23:50 UTC
Latest fix in 6.3.1 does work, but only partially. When PC gets back from sleep, it indeed saves proper brightness level, **but you are no longer able to change brightness levels with Fn+Up/Down, so you're not able to bring it to other level.**
Comment 8 Nate Graham 2025-02-24 16:44:02 UTC
*** Bug 500609 has been marked as a duplicate of this bug. ***
Comment 9 Nate Graham 2025-02-28 17:32:32 UTC
*** This bug has been marked as a duplicate of bug 494408 ***