There is discussion and a fix for this issue at https://lists.freedesktop.org/archives/nouveau/2021-December/039597.html https://lists.freedesktop.org/archives/nouveau/2021-December/039609.html
- Bug#1000681: linux-image-5.15.0-1-amd64: 5.15 u... James Tocknell
- Bug#1000681: linux-image-5.15.0-1-amd64: 5... Stefan Fritsch
- Bug#1000681: linux-image-5.15.0-1-amd64: 5... Stefan Fritsch
- Bug#1000681: linux-image-5.15.0-1-amd6... Salvatore Bonaccorso
- Bug#1000681: marked as done (linux-image-5... Debian Bug Tracking System
- Bug#1000681: marked as done (linux-image-5... Debian Bug Tracking System