https://bugs.kde.org/show_bug.cgi?id=517290
Bug ID: 517290
Summary: External HDMI monitor does not wake after screen
blanking (DDC working: false)
Classification: Plasma
Product: plasmashell
Version First 6.6.1
Reported In:
Platform: Fedora RPMs
OS: Linux
Status: REPORTED
Severity: normal
Priority: NOR
Component: Power management & brightness
Assignee: [email protected]
Reporter: [email protected]
Target Milestone: 1.0
When screens turn off due to inactivity (screen blanking), only the internal
laptop display wakes on activity. The external HDMI monitor stays off and
requires manual intervention (Super+P or kscreen-doctor).
This is NOT a suspend/resume issue — the system never suspended, only displays
were blanked by power management.
Logs show PowerDevil detects HDMI display but DDC communication fails:
org_kde_powerdevil: DDCA_EVENT_DISPLAY_CONNECTED, card1-HDMI-A-1, ddc
working: false
org_kde_powerdevil: DDCA_EVENT_DDC_ENABLED, card1-HDMI-A-1, ddc working:
false
Steps to reproduce:
1. Have external HDMI monitor connected and active
2. Leave system idle until screens blank
3. Move mouse or press key to wake
4. Internal display wakes, external stays off
Expected: both monitors wake
Actual: only internal monitor wakes
System:
- Fedora 43, Kernel 6.18.13-200.fc43.x86_64
- KDE Plasma 6.6.1, KWin 6.6.1, Wayland
- Intel Raptor Lake-P Iris Xe (i915)
- Internal: eDP-1 (1920x1200), External: HDMI-A-1 (1680x1050)
Workaround: physically unplugging and replugging the HDMI cable restores
the external monitor. After that, Super+P also starts working again.
Super+P and kscreen-doctor do NOT work while the monitor is in the
unresponsive state — only physical reconnection of the HDMI cable works.
This suggests KWin completely loses the output after screen blanking,
not just a PowerDevil/DDC power signal issue.
--
You are receiving this mail because:
You are watching all bug changes.
