Heads up, I've tried to completely upgrade the default 5.38 image to what repositories allow, and the video acceleration (VDPAU) did not break.
Strangely there is a10disp package that on 5.31->5.38 was upgraded to now non-available version, but this is clearly not the issue, just curiosity.
Also there appeared (in the upgraded image) file "/etc/X11/xorg.conf.d/80-armsoc-sun4i.conf" with some different Xorg configuration with Dri2 enabled, and "/etc/X11/Xsession.d/20vdpau-va-gl" with commented out contents (i suspect test installed, not purged xserver-xorg-video-armsoc-sun4i package).
But running the upgraded and image versions side by side, I've compared Xorg outputs, and determined, there is no difference in Xorg configuration, that is responsible.
There are also no additional or missing files in /etc configuration structure, that could cause the issues.
Comparing /boot/armbianEnv.txt and /boot/script.bin(fex) and /boot/boot.cmd(scr) and kernel cmdline, there is no difference.
So the issue must be somewhere else, and I currently don't know where to look
smarek got a reaction from Whoami in Sunxi VDPAU does not work in 5.38 on Banana Pi