https://bugs.kde.org/show_bug.cgi?id=523782
Bug ID: 523782
Summary: Auto-suspend not triggered when display mode is set to
"Only use external screen" with no external display
connected
Classification: Applications
Product: systemsettings
Version First 6.7.3
Reported In:
Platform: KDE Linux
OS: Linux
Status: REPORTED
Severity: normal
Priority: NOR
Component: kcm_kscreen
Assignee: [email protected]
Reporter: [email protected]
CC: [email protected]
Target Milestone: ---
Product: plasma-powerdevil (or plasma-workspace)
Version: plasmashell 6.7.3
Platform: KDE Plasma, Wayland
OS NAME="KDE neon"
VERSION_ID="24.04"
VERSION="User Edition"
VERSION_CODENAME=noble
Severity: Normal
Summary:
When the KDE display selector is set to "Only use external screen" mode but no
external display is physically connected, the automatic suspend (scheduled via
Power Management settings — "When inactive: Sleep after N minutes") is never
triggered. Switching the display mode to "Only use built-in screen" resolves
the issue, and auto-suspend works as expected.
Steps to Reproduce:
Open KDE System Settings → Power Management → On Battery (or On AC Power).
Set "When inactive" to "Sleep" after a short timeout (e.g., 2 minutes for
testing).
Confirm that the "Even when an external monitor is connected" checkbox is
unchecked.
Ensure no external display is physically connected.
Set the display selector (via the Display Configuration applet or
kscreen-doctor) to "Only use external screen" mode.
Leave the machine idle and wait past the configured suspend timeout.
Observe that the system does not suspend.
Expected behavior:
The system should suspend after the configured idle timeout, regardless of the
display mode selection. Since no external monitor is connected, there is no
reason to inhibit suspend.
Actual behavior:
The system does not suspend. No timeout is triggered, and the machine remains
awake indefinitely.
Workaround:
Switch the display selector to "Only use built-in screen" mode. Auto-suspend
then works correctly.
Additional context:
The systemd-inhibit --list output shows PowerDevil holding a block on
suspend/handle-power-key/handle-suspend-key. This is expected behavior when
PowerDevil is managing power events. However, when no external display is
present, PowerDevil appears to incorrectly determine that an external monitor
configuration should inhibit idle suspend.
It seems PowerDevil may be checking the display mode setting rather than the
actual presence of an external display. The unchecking of "Even when an
external monitor is connected" should logically override any monitor-related
sleep inhibition, but it appears this setting only checks the active display
mode rather than detecting whether a physical display is connected.
Relevant processes from systemd-inhibit --list:
PowerDevil (PID 4158) — block on sleep/power keys
NetworkManager (PID 1234) — delay on sleep (normal)
UPower (PID 2277) — delay on sleep (normal)
kwin_wayland (PID 3958) — delay on sleep (screen lock)
Windowing system: Wayland (kwin_wayland)
Power-profiles-daemon is installed and running; TLP is not installed (no
conflict).
Manual systemctl suspend works correctly — the issue is only with automatic
idle-triggered suspend.
Diagnostic logs:
kscreen-doctor --outputs
Output: 1 eDP-1 0f1d653b-fc16-4fc4-a76f-9c86dcc56783
enabled
connected
priority 1
Panel
replication source:0
Modes: 1:[email protected]*! 2:[email protected] 3:[email protected]
4:[email protected] 5:[email protected] 6:[email protected] 7:[email protected]
8:[email protected]
Custom modes: None
Geometry: 0,0 1920x1080
Scale: 1
Rotation: 1
Overscan: 0
Vrr: incapable
RgbRange: Automatic
HDR: incapable
Wide Color Gamut: incapable
ICC profile: none
Color profile source: sRGB
Color power preference: prefer efficiency and performance
Brightness control: supported, set to 15% and dimming to 100%
Color resolution: automatic (10), range: [6; 12] bits per color
Allow EDR: always
Sharpness control: unsupported
Automatic brightness: unsupported
Auto Rotate Policy: incapable
Adaptive backlight modulation: unsupported
upower -d
Device: /org/freedesktop/UPower/devices/battery_BAT0
native-path: BAT0
serial: 2329
power supply: yes
updated: dim. 02 août 2026 20:02:09 (2 seconds ago)
has history: yes
has statistics: yes
battery
present: yes
rechargeable: yes
state: discharging
warning-level: none
energy: 13,193 Wh
energy-empty: 0 Wh
energy-full: 30,681 Wh
energy-full-design: 37,004 Wh
energy-rate: 4,666 W
voltage: 7,472 V
charge-cycles: N/A
time to empty: 2,8 hours
percentage: 43%
capacity: 82,9127%
technology: lithium-ion
icon-name: 'battery-good-symbolic'
History (rate):
1785693729 4,666 discharging
1785693699 4,712 discharging
1785693669 6,026 discharging
1785693639 4,643 discharging
Device: /org/freedesktop/UPower/devices/line_power_ADP0
native-path: ADP0
power supply: yes
updated: dim. 02 août 2026 19:37:59 (1452 seconds ago)
has history: no
has statistics: no
line-power
warning-level: none
online: no
icon-name: 'ac-adapter-symbolic'
Device: /org/freedesktop/UPower/devices/DisplayDevice
power supply: yes
updated: dim. 02 août 2026 20:02:09 (2 seconds ago)
has history: no
has statistics: no
battery
present: yes
state: discharging
warning-level: none
energy: 13,193 Wh
energy-full: 30,681 Wh
energy-rate: 4,666 W
charge-cycles: N/A
time to empty: 2,8 hours
percentage: 43%
icon-name: 'battery-good-symbolic'
Daemon:
daemon-version: 1.90.3
on-battery: yes
lid-is-closed: no
lid-is-present: yes
critical-action: HybridSleep
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