Some new findings. I saw an email about fedora 33 working with 5.9 and so tried a live version with Rawhide and 5.10.0. No lockup. One difference was Wayland. So I rebooted my Opensuse TW with kernel 5.9.8 and switched to Wayland in SDDM. No lockups for 1h last night and no lockups for 1h this morning. Anyone got some suggestions how to proceed with the fault isolation with kernel 5.9, i915 and X?