https://bugs.kde.org/show_bug.cgi?id=525537

Peter Ferenczy <[email protected]> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |[email protected]

--- Comment #11 from Peter Ferenczy <[email protected]> ---
I think I found the cause, and it doesn't need a suspend to trigger.

It's the spinner next to the Wi-Fi switch in the Networks popup. If the popup
is closed while that spinner is still showing, its fade-out animation never
finishes, and plasmashell keeps redrawing the desktop every frame.

Steps to reproduce:
1. Click the Networks icon in the system tray. The spinner appears next to the
Wi-Fi switch.
2. Close the popup within a second, while the spinner is still visible.
3. plasmashell now redraws the desktop at the full refresh rate (~8% CPU here,
plus X/KWin).

This reproduces every time. If you instead keep the popup open until the
spinner disappears, nothing happens. Opening it again and waiting also clears
an already-stuck state, which is probably why it sometimes "ends on its own".

Why: the spinner (BusyIndicator.qml in libplasma) fades out with an
OpacityAnimator. Animators only advance while their window is being rendered,
and the hidden popup isn't. So the animation stays "running" forever. As long
as any animation runs, Qt keeps rendering the window that is on screen, which
is the desktop when the panel is auto-hidden.

Evidence: with gdb I read the running animation out of plasmashell. It's a
QQuickOpacityAnimatorJob whose target sits under QQuickBusyIndicator <
QQuickSwitch < ToolBar, inside a hidden PlasmaQuick::AppletPopup. qmlprofiler
and perf agree: one animation, ticking every frame, changing nothing.

Likely fix: the same one-line change as bug 477855 (libplasma commit
2b7a81002a93e59252d96f36dac33c9e08fdfb77, which did it for ButtonShadow.qml).
In BusyIndicator.qml, replace OpacityAnimator with NumberAnimation in the
opacity Behavior. It still uses OpacityAnimator on master. I haven't tested
that patch.

Setup: Plasma 6.6.6, Qt 6.11.1, X11, Intel iGPU, panel on auto-hide. So this
isn't specific to Wayland or the reporter's hardware.

-- 
You are receiving this mail because:
You are watching all bug changes.

Reply via email to