My computer (which has an NVIDIA card) has a rendering problem that is very annoying.
Sometimes the X server 'locks up' after freezing (or whatever's going on in there because VLC music loops at the current packet then) for ~1 second, the pointer becomes invisible, the keyboard & mouse won't work and I get a screen that looks like this:
except the colors are different each time. I enabled ctrl-alt-backspace and alt-sysrq-[rk] keys and not even those have an effect, to recover I must do a cold reboot.
Sometimes instead of getting the above screen I get a console full of kernel errors like nouveau: failed to idle channel XXX. Then after a few seconds all programs get killed (while in the tty). This might be an X server because my
xgamma settings (which are reset every logout) are even then still in effect.
And then even the console itself disappears, no login screen, just black (and the only way out is also a cold reboot).
The strangest part is that KTorrent (which was downloading a file when this happened) was still transmitting data during the lockup, according to my modem LED. All programs are killed, can reproduce with VLC playing music.
In particular, I can't run any JavaFX 8 programs (not even the simplest one which creates an empty window) because when I run
java -jar my.jar, the window appears but in a degenerated/rendering-out-of-sync form, and either a) the screen locks up after a few seconds of b) after a few (un)maximizing/resizing the above happens. Also happens sometimes while I use firefox or even when there are no windows open.
wmctrl -l shows that the lockup screen is not a window. Also, as said above, windows/programs are still open so all GUI processes wouldn't be killed. This is very confusing and I'm out of ideas.