Dear all on this bug,
I would like to briefly point out these crashes are showing kernel errors, the kernel / amdgpu modesetting seems to be a very significant part of the problem if I am not mistaken, this bug being against the X-server component. I would say, from the deb-10 / MX19.4 side of things with a GCN1.1 series amdgpu card, updated 5.10 kernels (i.e. backports of deb11 bullseye kernels) have incrementally improved problems with crashing, resuming from sleep, and so-on. With 5.10.0-7 I seem to be able to reliably unpower and repower monitors and manage to keep X working without crash and just xrandr fix up monitor layout. Similar applies to sleep/resume situation!. I know the kernel amdgpu modesetting driver is a huge part of that work. In short, I would highly recommend trying different kernels on your deb11 testing machines and see how that affects your situation, and in any case report which kernels are in use in the crash scenario. Debian11 bullseye currently has 5.10.0-6 and I understand the 5.10.0-7 packages are to hit bullseye soon (through hard freeze). 5.10.0-7 is in sid and can be manually downloaded, or installed via *temporary* adding sid to sources.list and then removing from sources (or pinning to avoid all packages going to sid). https://packages.debian.org/search?keywords=linux-image-5.10.0-7-amd64 Also, I would note, testing the older linux-image-4.19.0-16 may be worthwhile, I get impression this (buster) kernel should nonetheless 'work' with bullseye and may assist with the 'it used to work' scenario. Hope that helps, --Simon
