Bug 453031

Summary:	[wayland/nvidia] loading a layout that contains system tray widget causes latte to freeze
Product:	[Unmaintained] lattedock	Reporter:	Johan Sköld <johan>
Component:	application	Assignee:	Michail Vourlakos <mvourlakos>
Status:	RESOLVED FIXED
Severity:	major	CC:	kdedev
Priority:	NOR
Version First Reported In:	0.10.8
Target Milestone:	---
Platform:	Fedora RPMs
OS:	Linux
See Also:	https://bugs.kde.org/show_bug.cgi?id=492143
Latest Commit:		Version Fixed In:
Sentry Crash Report:

Description Johan Sköld 2022-04-26 03:00:03 UTC

SUMMARY
If I add a System Tray widget to an empty panel, and restart latte-dock, it freezes on startup and I have to kill it with SIGKILL. The same thing appears to happen if I load a pre-supplied layout that contains a System Tray.

STEPS TO REPRODUCE
1. Create a new empty layout.
2. Add an empty panel to the layout.
3. Add a System Tray widget to that panel.
4. Restart latte-dock.

OBSERVED RESULT
latte-dock freezes on startup.

EXPECTED RESULT
latte-dock appears and shows the new panel.

SOFTWARE/OS VERSIONS
Linux/KDE Plasma: Linux fedora 5.17.3-302.fc36.x86_64
(available in About System)
KDE Plasma Version: 5.24.3
KDE Frameworks Version: 5.91.0
Qt Version: 5.13.3

ADDITIONAL INFORMATION
I am using Wayland with nvidia's proprietary drivers (510.60.02). I attached gdb to the process while it was frozen to get a backtrace. Call stack pasted below. It never returns from that poll call.

	#0  0x00007ff09c97ce8f in __GI___poll (fds=fds@entry=0x7ffc3cd97df0, nfds=nfds@entry=1, timeout=timeout@entry=-1) at ../sysdeps/unix/sysv/linux/poll.c:29
	#1  0x00007ff09c735054 in poll (__timeout=-1, __nfds=1, __fds=0x7ffc3cd97df0) at /usr/include/bits/poll2.h:39
	#2  wl_display_poll (display=0x565532db4650, events=1) at ../src/wayland-client.c:1866
	#3  wl_display_dispatch_queue (queue=<optimized out>, display=<optimized out>) at ../src/wayland-client.c:1939
	#4  wl_display_dispatch_queue (display=0x565532db4650, queue=queue@entry=0x565534735eb0) at ../src/wayland-client.c:1912
	#5  0x00007ff08968611e in wlEglWaitFrameSync (surface=0x565534736020) at ../src/wayland-eglsurface.c:157
	#6  wlEglSwapBuffersWithDamageHook (eglDisplay=<optimized out>, eglSurface=0x565534736020, rects=0x0, n_rects=0) at ../src/wayland-eglswap.c:100
	#7  0x00007ff0892a7f9e in  () at /lib64/libEGL_nvidia.so.0
	#8  0x00007ff089247b40 in  () at /lib64/libEGL_nvidia.so.0
	#9  0x00007ff0896e8925 in QtWaylandClient::QWaylandGLContext::swapBuffers(QPlatformSurface*) (this=0x5655343adf40, surface=0x565533185840) at ../../../../hardwareintegration/client/wayland-egl/qwaylandglcontext.cpp:503
	#10 0x00007ff09ef33086 in QSGGuiThreadRenderLoop::renderWindow(QQuickWindow*) (this=0x56553312e6c0, window=<optimized out>) at scenegraph/qsgrenderloop.cpp:796
	#11 0x00007ff09ef34122 in QSGGuiThreadRenderLoop::exposureChanged(QQuickWindow*) (this=0x56553312e6c0, window=<optimized out>) at scenegraph/qsgrenderloop.cpp:852
	#12 0x00007ff09d5d4715 in QWindow::event(QEvent*) (this=0x56553308fdd0, ev=<optimized out>) at kernel/qwindow.cpp:2438
	#13 0x00007ff09dd96c22 in QApplicationPrivate::notify_helper(QObject*, QEvent*) (this=<optimized out>, receiver=0x56553308fdd0, e=0x7ffc3cd98260) at kernel/qapplication.cpp:3637
	#14 0x00007ff09d031118 in QCoreApplication::notifyInternal2(QObject*, QEvent*) (receiver=0x56553308fdd0, event=0x7ffc3cd98260) at kernel/qcoreapplication.cpp:1064
	#15 0x00007ff09d5ca3c5 in QGuiApplicationPrivate::processExposeEvent(QWindowSystemInterfacePrivate::ExposeEvent*) (e=0x56553362cf30) at kernel/qguiapplication.cpp:3251
	#16 0x00007ff09d5a8f7c in QWindowSystemInterface::sendWindowSystemEvents(QFlags<QEventLoop::ProcessEventsFlag>) (flags=...) at kernel/qwindowsysteminterface.cpp:1169
	#17 0x00007ff09bf804c4 in userEventSourceDispatch(_GSource*, int (*)(void*), void*) () at /lib64/libQt5WaylandClient.so.5
	#18 0x00007ff09b557f4f in g_main_dispatch (context=0x565532dce060) at ../glib/gmain.c:3417
	#19 g_main_context_dispatch (context=0x565532dce060) at ../glib/gmain.c:4135
	#20 0x00007ff09b5ad168 in g_main_context_iterate.constprop.0 (context=context@entry=0x565532dce060, block=block@entry=1, dispatch=dispatch@entry=1, self=<optimized out>) at ../glib/gmain.c:4211
	#21 0x00007ff09b5558e0 in g_main_context_iteration (context=0x565532dce060, may_block=1) at ../glib/gmain.c:4276
	#22 0x00007ff09d081c8a in QEventDispatcherGlib::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) (this=0x565532dcaf10, flags=...) at kernel/qeventdispatcher_glib.cpp:423
	#23 0x00007ff09d02fb7a in QEventLoop::exec(QFlags<QEventLoop::ProcessEventsFlag>) (this=this@entry=0x7ffc3cd98530, flags=..., flags@entry=...) at ../../include/QtCore/../../src/corelib/global/qflags.h:69
	#24 0x00007ff09d037c22 in QCoreApplication::exec() () at ../../include/QtCore/../../src/corelib/global/qflags.h:121
	#25 0x00005655320a5990 in main(int, char**) (argc=<optimized out>, argv=<optimized out>) at /usr/src/debug/latte-dock-0.10.8-1.fc36.x86_64/app/main.cpp:423

Comment 1 Michail Vourlakos 2022-05-09 17:41:45 UTC

qt version is pretty old... I am pretty sure that you need latest Plasma and Qt in order for having a little decent support for Wayland and NVidia

Comment 2 Johan Sköld 2022-05-10 05:06:34 UTC

Ah, my apologies. The Qt version is 5.15.3, not 5.13.3.

Comment 3 Michail Vourlakos 2022-05-10 07:04:45 UTC

(In reply to johan from comment #2)
> Ah, my apologies. The Qt version is 5.15.3, not 5.13.3.

nonetheless, nvidia+plasma+wayland combination has more maturity steps to achieve in the coming plasma releases

Comment 4 TraceyC 2024-08-27 14:39:12 UTC

Thank you for the bug report. Unfortunately we were not able to get to it yet. Can we ask you to please check if this is still an issue with either Plasma 5.27 (the current LTS version) or Plasma 6.1.4 (the latest released version)? This may be related to another, more recent crash report.

Note: backtrace seems similar to https://bugs.kde.org/show_bug.cgi?id=492143

Comment 5 Johan Sköld 2024-09-14 06:38:35 UTC

(In reply to TraceyC from comment #4)
> Thank you for the bug report. Unfortunately we were not able to get to it
> yet. Can we ask you to please check if this is still an issue with either
> Plasma 5.27 (the current LTS version) or Plasma 6.1.4 (the latest released
> version)? This may be related to another, more recent crash report.
> 
> Note: backtrace seems similar to https://bugs.kde.org/show_bug.cgi?id=492143

Honestly speaking I had completely forgotten about this bug, and my system is no longer even remotely the same. I no longer use an nvidia card for instance, nor the same linux distribution. So sadly I cannot check if it's still a problem, but it's also no longer a problem for me either.

I appreciate you getting back to me, but feel free to close this. I'd do it myself but I don't know which status you'd prefer. :)

Comment 6 TraceyC 2024-09-18 17:22:06 UTC

Hi Johan,

Thanks for your response. I'm glad to hear things are working for you now. I'll go ahead and close this out. Please feel free to report any other bugs you might find :)