Time to time kwin freezes when I click on combo box. Most offen it occurs in Konqueror, but in Firefox also. I believe that it happens more offen when I click on combo box when page continues to load (i.e. render). It started from KWin 4.6.0.


Back trace of kwin:

#0  0x00007fcba1582cc7 in ioctl () from /lib/libc.so.6
#1  0x00007fcb96a6dd88 in drmIoctl () from /usr/lib/libdrm.so.2
#2  0x00007fcb96a7010c in drmCommandWriteRead () from /usr/lib/libdrm.so.2
#3  0x00007fcb86e991c4 in r600_context_flush (ctx=0xfbfd38) at r600_hw_context.c:1128
#4  0x00007fcb86e79dac in r600_flush (ctx=0xfbfa30, fence=<value optimized out>) at r600_pipe.c:71
#5  0x00007fcb86f41952 in st_glFlush (ctx=<value optimized out>) at state_tracker/st_cb_flush.c:126
#6  0x00007fcba190d170 in ?? () from /usr/lib/libkdeinit4_kwin.so
#7  0x00007fcba1914e25 in ?? () from /usr/lib/libkdeinit4_kwin.so
#8  0x00007fcba1915605 in ?? () from /usr/lib/libkdeinit4_kwin.so
#9  0x00007fcba18fc6a2 in ?? () from /usr/lib/libkdeinit4_kwin.so
#10 0x00007fcb9cc3ce69 in QObject::event(QEvent*) () from /usr/lib64/qt4/libQtCore.so.4
#11 0x00007fcb9d879f04 in QApplicationPrivate::notify_helper(QObject*, QEvent*) () from /usr/lib64/qt4/libQtGui.so.4
#12 0x00007fcb9d87ea8a in QApplication::notify(QObject*, QEvent*) () from /usr/lib64/qt4/libQtGui.so.4
#13 0x00007fcba108f2e6 in KApplication::notify(QObject*, QEvent*) () from /usr/lib/libkdeui.so.5
#14 0x00007fcb9cc28f5b in QCoreApplication::notifyInternal(QObject*, QEvent*) () from /usr/lib64/qt4/libQtCore.so.4
#15 0x00007fcb9cc5672e in ?? () from /usr/lib64/qt4/libQtCore.so.4
#16 0x00007fcb9cc56870 in QEventDispatcherUNIX::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) () from /usr/lib64/qt4/libQtCore.so.4
#17 0x00007fcb9d92020b in ?? () from /usr/lib64/qt4/libQtGui.so.4
#18 0x00007fcb9cc28322 in QEventLoop::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) () from /usr/lib64/qt4/libQtCore.so.4
#19 0x00007fcb9cc28564 in QEventLoop::exec(QFlags<QEventLoop::ProcessEventsFlag>) () from /usr/lib64/qt4/libQtCore.so.4
#20 0x00007fcb9cc2c9cb in QCoreApplication::exec() () from /usr/lib64/qt4/libQtCore.so.4
#21 0x00007fcba189aacb in kdemain () from /usr/lib/libkdeinit4_kwin.so
#22 0x00007fcba14d1ebd in __libc_start_main () from /lib/libc.so.6
#23 0x0000000000400789 in _start ()

OpenGL vendor string: X.Org
OpenGL renderer string: Gallium 0.4 on AMD JUNIPER
OpenGL version string: 2.1 Mesa 7.11-devel