https://bugs.freedesktop.org/show_bug.cgi?id=111789
--- Comment #3 from Vlado Plaga rechner@vlado-do.de --- Cool, thank you, "usual user"! Your "cma=256M@2G" works for me. No more "command buffer outside valid memory window", and I could start Weston with weston-launch! The terminal there had a nice shadow, and I could drag it around smoothly.
(But Fedora 31 for arm apparently does not offer vlc, mplayer, or kodi... so I'm gonna try Armbian again next, with the switch)