On Sat, 9 Jul 2022, Thomas Dickey wrote: > On Sat, Jul 09, 2022 at 02:39:41PM +1000, Tim Connors wrote: > > This has happened ever since I changed my hardware -- mostly updating > > my video card to a radeon RX570 -- necessitating new versions of some > > drivers and kernel. While I would happily accept that the video card > > might have some dodgy memory (note to self: find a GPU memory stress > > tester), this corruption has not affected any other program other than > > xterm's scrollback buffer, so I wonder if it's a bug instead. > > > > Screengrabs of the symptom: > > > > https://rather.puzzling.org/~tconnors/tmp/screengrab-xterm-scrollback-corruption.png > > https://rather.puzzling.org/~tconnors/tmp/screengrab-xterm-scrollback-corruption2.png > > > > radeon amdgpu drivers and firmware are the latest version allowed by > > otherwise being on debian stable - ie, > > It looks like the problem is in the drivers (not xterm). > > That could be defective implementation of XCopyArea, for instance. > > https://bugs.freedesktop.org/show_bug.cgi?id=110214
For those following along at home, for debian bullseye, the solution was simply to downgrade back to (old)stable's kernels, but alas that is no longer a solution for debian bookworm - the framebuffer bug is still there in 6.1 and 6.5 kernels. However, one of those bugs somewhere hinted about using xcompmgr. Running that in fvwm has solved my problem (as well as solving excessive CPU usage in mozilla related to it wanting to continually update windows that aren't actually in view). No apparent sideeffects at all, which seems rather strange for something coming out of the shiny new world. I have no idea how xcompmgr fixes this, but it fixes the screen artefacts in xterm nevertheless! -- Tim Connors