More 64K page problems and some solutions

Meanwhile, as the question of a 4K-page Fedora 34 remains as yet undecided, if you are using a more recent video card with your Linux OpenPOWER system Trung Lê reports that kernel 5.11.x still crashes with 64K pages on his AMD R9 Nano. (Older cards, like the AMD WX7100 workstation GPU in this Talos II that Raptor sells as a BTO option, are unaffected may also be affected — see comments for more.) This is relevant since Fedora 33 is moving to 5.11. If you're a Fedora 33 user and wish to continue with the 5.10.x series until a fix for amdgpu emerges, kernels are available from his Github project.

In the meantime, speaking personally as one of those people who still use FireWire/IEEE-1394, 4K pages are at least part of the problem as to why FireWire cards don't seem to work in my F33 Talos II (I tried a Rosewill one first without success, and more recently an Iocrest card using a more typical Texas Instruments controller). Although a patch for 64K page support was initially submitted, it was rejected, and the followup patch was never tested. I'll be getting around to trying this myself and hopefully getting it into the kernel, but in the meantime report back if using the patch works for you (I still use some FireWire devices, particularly for video capture and legacy interchange with the Power Macs that lurk around here).