Have sddm.service (or lightdm.service) running as login manager. Log into the system The display manager screen gets replaced by the kde logo and a rotating 'spinner' beneath it. The 'spinner' disappears and ... nothing happens. Kde logo is still there and remains visible... (on other systems, the plasma desktop is now shown and replaces the kde logo) Workaround to get to the desktop: press Ctrl-Alt F2, and then Alt-F1 to go back. Now, the desktop is here in its full glory :-) Same workaround is sometimes necessary when working with plasma, the taskbar is stuck (no updates, no context menu, no kicker) and the context menu on the desktop does not appear when right-clicking. Just make a short detour to the vconsole and back to the gui and all is fine again. This is _very_ annoying!!! Happens on different systems - with a fresh install of fedora25/kde spin (kernel 4.6 and plasma < 5.8) it is happening on every system i installed recently (lenovo laptops t420, t440, both intel graphics, desktop with core2 q8200 and intel graphics) - it seems to be fixed when updated to current repo releases on the more current systems (lenovo laptops), but it happens often - not always - on the desktop with the q8200/intel graphics I already tried different compositing options, openGL 3.1/2.0/XRender but the problem remains.
When you switch away to another TTY can you run pgrep and see if a process called kslpash is running. Also have you tried just waiting?
yes of course i did wait :-) But desktop did just not come up. Sometimes, esp. when switching users, there is a long delay until the desktop appears by itself (so yes, waiting helps) But to shorten the waiting time, a switch to console and back to gui does the trick immediately. will check for ksplash when back on that specific q8200 machine
marking as needsinfo until you get back to me on that then. Also it sounds like you might be hitting http://bugs.kde.org/373427 manifesting in a different way. Would you be able to check that by either enabling DRI3 (see comments in thread) or getting a newest Xorg.
Thanks for the analysis so far, but latest updates(-testing) of fedora solved this particular problem. No more hangs when logging in, no need to switch to console and back. Marking this as resolved