Application: plasmashell (5.4.1)

Qt Version: 5.5.0
Operating System: Linux 4.1.10-200.fc22.x86_64 x86_64
Distribution: "Fedora release 22 (Twenty Two)"

-- Information about the crash:
My set-up has two monitors - one connected via DisplayPort the other via HDMI all from on-board mobo with Intel Z87 chipset.
If the system is left running with the monitors turned on then generally it is stable, but as soon as monitors are turned off then it can all go a bit wierd - the default KDE panel fails to appear or moves monitors, random crashes after login, one desktop (monitor) appearing completely blank (though apps, mouse, etc. do work on it), etc. 
Often, attempting to add the default panel back on results in nothing happening, then after logoff and back on, panels may appear on top of each other or at random places on one of the monitors.

Fedora 22, x64.

The crash can be reproduced sometimes.

-- Backtrace:
Application: Plasma (plasmashell), signal: Segmentation fault
Using host libthread_db library "/lib64/libthread_db.so.1".
81	T_PSEUDO (SYSCALL_SYMBOL, SYSCALL_NAME, SYSCALL_NARGS)
[Current thread is 1 (Thread 0x7f68fc3ae900 (LWP 3301))]

Thread 8 (Thread 0x7f68f4f9c700 (LWP 3309)):
#0  0x0000003456af72fd in poll () at ../sysdeps/unix/syscall-template.S:81
#1  0x000000345aa0a182 in poll (__timeout=-1, __nfds=1, __fds=0x7f68f4f9bbc0) at /usr/include/bits/poll2.h:46
#2  _xcb_conn_wait (c=c@entry=0x26cf3d0, cond=cond@entry=0x26cf410, vector=vector@entry=0x0, count=count@entry=0x0) at xcb_conn.c:459
#3  0x000000345aa0bc77 in xcb_wait_for_event (c=0x26cf3d0) at xcb_in.c:648
#4  0x00007f68f5842999 in QXcbEventReader::run (this=0x26d9aa0) at qxcbconnection.cpp:1198
#5  0x00000037e74a254e in QThreadPrivate::start (arg=0x26d9aa0) at thread/qthread_unix.cpp:331
#6  0x0000003456e07555 in start_thread (arg=0x7f68f4f9c700) at pthread_create.c:333
#7  0x0000003456b02b9d in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:109

Thread 7 (Thread 0x7f68ee6e5700 (LWP 3323)):
#0  0x0000003456af72fd in poll () at ../sysdeps/unix/syscall-template.S:81
#1  0x0000003458a49dbc in g_main_context_poll (priority=2147483647, n_fds=1, fds=0x7f68e8003070, timeout=<optimized out>, context=0x7f68e8000990) at gmain.c:4103
#2  g_main_context_iterate (context=context@entry=0x7f68e8000990, block=block@entry=1, dispatch=dispatch@entry=1, self=<optimized out>) at gmain.c:3803
#3  0x0000003458a49ecc in g_main_context_iteration (context=0x7f68e8000990, may_block=may_block@entry=1) at gmain.c:3869
#4  0x00000037e76d9dab in QEventDispatcherGlib::processEvents (this=0x7f68e80008c0, flags=...) at kernel/qeventdispatcher_glib.cpp:420
#5  0x00000037e7680daa in QEventLoop::exec (this=this@entry=0x7f68ee6e4ca0, flags=..., flags@entry=...) at kernel/qeventloop.cpp:204
#6  0x00000037e749d5a4 in QThread::exec (this=this@entry=0x27a6160) at thread/qthread.cpp:503
#7  0x00000037fb0d9245 in QQmlThreadPrivate::run (this=0x27a6160) at /usr/src/debug/qtdeclarative-opensource-src-5.5.0/src/qml/qml/ftw/qqmlthread.cpp:141
#8  0x00000037e74a254e in QThreadPrivate::start (arg=0x27a6160) at thread/qthread_unix.cpp:331
#9  0x0000003456e07555 in start_thread (arg=0x7f68ee6e5700) at pthread_create.c:333
#10 0x0000003456b02b9d in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:109

Thread 6 (Thread 0x7f68e5d9a700 (LWP 3357)):
#0  0x0000003456af72fd in poll () at ../sysdeps/unix/syscall-template.S:81
#1  0x0000003458a49dbc in g_main_context_poll (priority=2147483647, n_fds=1, fds=0x7f68e0002e70, timeout=<optimized out>, context=0x7f68e0000990) at gmain.c:4103
#2  g_main_context_iterate (context=context@entry=0x7f68e0000990, block=block@entry=1, dispatch=dispatch@entry=1, self=<optimized out>) at gmain.c:3803
#3  0x0000003458a49ecc in g_main_context_iteration (context=0x7f68e0000990, may_block=may_block@entry=1) at gmain.c:3869
#4  0x00000037e76d9dab in QEventDispatcherGlib::processEvents (this=0x7f68e00008c0, flags=...) at kernel/qeventdispatcher_glib.cpp:420
#5  0x00000037e7680daa in QEventLoop::exec (this=this@entry=0x7f68e5d99ca0, flags=..., flags@entry=...) at kernel/qeventloop.cpp:204
#6  0x00000037e749d5a4 in QThread::exec (this=this@entry=0x3366130) at thread/qthread.cpp:503
#7  0x00000037fb0d9245 in QQmlThreadPrivate::run (this=0x3366130) at /usr/src/debug/qtdeclarative-opensource-src-5.5.0/src/qml/qml/ftw/qqmlthread.cpp:141
#8  0x00000037e74a254e in QThreadPrivate::start (arg=0x3366130) at thread/qthread_unix.cpp:331
#9  0x0000003456e07555 in start_thread (arg=0x7f68e5d9a700) at pthread_create.c:333
#10 0x0000003456b02b9d in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:109

Thread 5 (Thread 0x7f68dffff700 (LWP 3483)):
#0  0x0000003458a8eec9 in g_mutex_lock (mutex=mutex@entry=0x7f68d8000990) at gthread-posix.c:1336
#1  0x0000003458a49581 in g_main_context_query (context=context@entry=0x7f68d8000990, max_priority=2147483647, timeout=timeout@entry=0x7f68dfffeb74, fds=fds@entry=0x7f68d8003070, n_fds=n_fds@entry=1) at gmain.c:3512
#2  0x0000003458a49d37 in g_main_context_iterate (context=context@entry=0x7f68d8000990, block=block@entry=1, dispatch=dispatch@entry=1, self=<optimized out>) at gmain.c:3790
#3  0x0000003458a49ecc in g_main_context_iteration (context=0x7f68d8000990, may_block=may_block@entry=1) at gmain.c:3869
#4  0x00000037e76d9dab in QEventDispatcherGlib::processEvents (this=0x7f68d80008c0, flags=...) at kernel/qeventdispatcher_glib.cpp:420
#5  0x00000037e7680daa in QEventLoop::exec (this=this@entry=0x7f68dfffeca0, flags=..., flags@entry=...) at kernel/qeventloop.cpp:204
#6  0x00000037e749d5a4 in QThread::exec (this=this@entry=0x344ae50) at thread/qthread.cpp:503
#7  0x00000037fb0d9245 in QQmlThreadPrivate::run (this=0x344ae50) at /usr/src/debug/qtdeclarative-opensource-src-5.5.0/src/qml/qml/ftw/qqmlthread.cpp:141
#8  0x00000037e74a254e in QThreadPrivate::start (arg=0x344ae50) at thread/qthread_unix.cpp:331
#9  0x0000003456e07555 in start_thread (arg=0x7f68dffff700) at pthread_create.c:333
#10 0x0000003456b02b9d in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:109

Thread 4 (Thread 0x7f68de9cf700 (LWP 3545)):
#0  pthread_cond_wait@@GLIBC_2.3.2 () at ../sysdeps/unix/sysv/linux/x86_64/pthread_cond_wait.S:185
#1  0x00000037fe185494 in QTWTF::TCMalloc_PageHeap::scavengerThread (this=0x37fe46de80) at /usr/src/debug/qtscript-opensource-src-5.5.0/src/3rdparty/javascriptcore/JavaScriptCore/wtf/FastMalloc.cpp:2359
#2  0x00000037fe1854d9 in QTWTF::TCMalloc_PageHeap::runScavengerThread (context=<optimized out>) at /usr/src/debug/qtscript-opensource-src-5.5.0/src/3rdparty/javascriptcore/JavaScriptCore/wtf/FastMalloc.cpp:1464
#3  0x0000003456e07555 in start_thread (arg=0x7f68de9cf700) at pthread_create.c:333
#4  0x0000003456b02b9d in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:109

Thread 3 (Thread 0x7f6857713700 (LWP 3577)):
#0  0x0000003456af72fd in poll () at ../sysdeps/unix/syscall-template.S:81
#1  0x0000003458a49dbc in g_main_context_poll (priority=2147483647, n_fds=1, fds=0x7f6850003060, timeout=<optimized out>, context=0x7f6850000990) at gmain.c:4103
#2  g_main_context_iterate (context=context@entry=0x7f6850000990, block=block@entry=1, dispatch=dispatch@entry=1, self=<optimized out>) at gmain.c:3803
#3  0x0000003458a49ecc in g_main_context_iteration (context=0x7f6850000990, may_block=may_block@entry=1) at gmain.c:3869
#4  0x00000037e76d9dab in QEventDispatcherGlib::processEvents (this=0x7f68500008c0, flags=...) at kernel/qeventdispatcher_glib.cpp:420
#5  0x00000037e7680daa in QEventLoop::exec (this=this@entry=0x7f6857712c50, flags=..., flags@entry=...) at kernel/qeventloop.cpp:204
#6  0x00000037e749d5a4 in QThread::exec (this=this@entry=0x3820050) at thread/qthread.cpp:503
#7  0x00000039a5cf6616 in QQuickPixmapReader::run (this=0x3820050) at /usr/src/debug/qtdeclarative-opensource-src-5.5.0/src/quick/util/qquickpixmapcache.cpp:754
#8  0x00000037e74a254e in QThreadPrivate::start (arg=0x3820050) at thread/qthread_unix.cpp:331
#9  0x0000003456e07555 in start_thread (arg=0x7f6857713700) at pthread_create.c:333
#10 0x0000003456b02b9d in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:109

Thread 2 (Thread 0x7f684ba78700 (LWP 3635)):
#0  0x0000003456af72fd in poll () at ../sysdeps/unix/syscall-template.S:81
#1  0x0000003458a49dbc in g_main_context_poll (priority=2147483647, n_fds=1, fds=0x7f68440048c0, timeout=<optimized out>, context=0x7f6844000990) at gmain.c:4103
#2  g_main_context_iterate (context=context@entry=0x7f6844000990, block=block@entry=1, dispatch=dispatch@entry=1, self=<optimized out>) at gmain.c:3803
#3  0x0000003458a49ecc in g_main_context_iteration (context=0x7f6844000990, may_block=may_block@entry=1) at gmain.c:3869
#4  0x00000037e76d9dab in QEventDispatcherGlib::processEvents (this=0x7f68440008c0, flags=...) at kernel/qeventdispatcher_glib.cpp:420
#5  0x00000037e7680daa in QEventLoop::exec (this=this@entry=0x7f684ba77c80, flags=..., flags@entry=...) at kernel/qeventloop.cpp:204
#6  0x00000037e749d5a4 in QThread::exec (this=<optimized out>) at thread/qthread.cpp:503
#7  0x00007f684cf6e397 in KCupsConnection::run() () from /lib64/libkcupslib.so
#8  0x00000037e74a254e in QThreadPrivate::start (arg=0x596c780) at thread/qthread_unix.cpp:331
#9  0x0000003456e07555 in start_thread (arg=0x7f684ba78700) at pthread_create.c:333
#10 0x0000003456b02b9d in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:109

Thread 1 (Thread 0x7f68fc3ae900 (LWP 3301)):
[KCrash Handler]
#6  0x00007f68e7bd471f in get_stencil_miptree (irb=0x66450f0) at brw_misc_state.c:215
#7  brw_workaround_depthstencil_alignment (brw=brw@entry=0x3955c68, clear_mask=clear_mask@entry=50) at brw_misc_state.c:231
#8  0x00007f68e7b5c883 in brw_clear (ctx=0x3955c68, mask=50) at brw_clear.c:235
#9  0x00000039a5d263fa in QSGBatchRenderer::Renderer::renderBatches (this=this@entry=0x66a8600) at /usr/src/debug/qtdeclarative-opensource-src-5.5.0/src/quick/scenegraph/coreapi/qsgbatchrenderer.cpp:2471
#10 0x00000039a5d2bde2 in QSGBatchRenderer::Renderer::render (this=<optimized out>) at /usr/src/debug/qtdeclarative-opensource-src-5.5.0/src/quick/scenegraph/coreapi/qsgbatchrenderer.cpp:2674
#11 0x00000039a5d37adf in QSGRenderer::renderScene (this=0x66a8600, bindable=...) at /usr/src/debug/qtdeclarative-opensource-src-5.5.0/src/quick/scenegraph/coreapi/qsgrenderer.cpp:208
#12 0x00000039a5d3832b in QSGRenderer::renderScene (this=<optimized out>, fboId=<optimized out>) at /usr/src/debug/qtdeclarative-opensource-src-5.5.0/src/quick/scenegraph/coreapi/qsgrenderer.cpp:168
#13 0x00000039a5d4871e in QSGRenderContext::renderNextFrame (this=0x28e0890, renderer=0x66a8600, fboId=<optimized out>) at /usr/src/debug/qtdeclarative-opensource-src-5.5.0/src/quick/scenegraph/qsgcontext.cpp:558
#14 0x00000039a5d9265b in QQuickWindowPrivate::renderSceneGraph (this=this@entry=0x355f8c0, size=...) at /usr/src/debug/qtdeclarative-opensource-src-5.5.0/src/quick/items/qquickwindow.cpp:383
#15 0x00000039a5d6301b in QSGGuiThreadRenderLoop::renderWindow (this=this@entry=0x30aa670, window=0x3590460) at /usr/src/debug/qtdeclarative-opensource-src-5.5.0/src/quick/scenegraph/qsgrenderloop.cpp:375
#16 0x00000039a5d64121 in QSGGuiThreadRenderLoop::event (this=0x30aa670, e=<optimized out>) at /usr/src/debug/qtdeclarative-opensource-src-5.5.0/src/quick/scenegraph/qsgrenderloop.cpp:471
#17 0x00000039a77544ac in QApplicationPrivate::notify_helper (this=this@entry=0x26c3480, receiver=receiver@entry=0x30aa670, e=e@entry=0x7ffd86bdc630) at kernel/qapplication.cpp:3717
#18 0x00000039a7759976 in QApplication::notify (this=0x7ffd86bdc9f0, receiver=0x30aa670, e=0x7ffd86bdc630) at kernel/qapplication.cpp:3500
#19 0x00000037e768361b in QCoreApplication::notifyInternal (this=0x7ffd86bdc9f0, receiver=0x30aa670, event=event@entry=0x7ffd86bdc630) at kernel/qcoreapplication.cpp:965
#20 0x00000037e76d8bad in sendEvent (event=0x7ffd86bdc630, receiver=<optimized out>) at ../../src/corelib/kernel/qcoreapplication.h:224
#21 QTimerInfoList::activateTimers (this=0x26b8c90) at kernel/qtimerinfo_unix.cpp:637
#22 0x00000037e76d90b1 in timerSourceDispatch (source=<optimized out>) at kernel/qeventdispatcher_glib.cpp:177
#23 0x0000003458a49a8a in g_main_dispatch (context=0x7f68f00016f0) at gmain.c:3122
#24 g_main_context_dispatch (context=context@entry=0x7f68f00016f0) at gmain.c:3737
#25 0x0000003458a49e20 in g_main_context_iterate (context=context@entry=0x7f68f00016f0, block=block@entry=1, dispatch=dispatch@entry=1, self=<optimized out>) at gmain.c:3808
#26 0x0000003458a49ecc in g_main_context_iteration (context=0x7f68f00016f0, may_block=may_block@entry=1) at gmain.c:3869
#27 0x00000037e76d9d8f in QEventDispatcherGlib::processEvents (this=0x270a330, flags=...) at kernel/qeventdispatcher_glib.cpp:418
#28 0x00000037e7680daa in QEventLoop::exec (this=this@entry=0x7ffd86bdc870, flags=..., flags@entry=...) at kernel/qeventloop.cpp:204
#29 0x00000037e7688e6c in QCoreApplication::exec () at kernel/qcoreapplication.cpp:1229
#30 0x00000039a64e724c in QGuiApplication::exec () at kernel/qguiapplication.cpp:1528
#31 0x00000039a77508e5 in QApplication::exec () at kernel/qapplication.cpp:2977
#32 0x00000000004302c3 in main (argc=2, argv=<optimized out>) at ../../shell/main.cpp:176

Possible duplicates by query: bug 351509, bug 343756.

Reported using DrKonqi