Additional helpful insights from osmoticum on the Nvidia forum: The Xorg modesetting DDX seems to be fighting with the Nvidia DDX for DRM nodes
[ 463.657] (II) modeset(G0): using drv /dev/dri/card0 but [ 463.658] (II) Applying OutputClass "nvidia" options to /dev/dri/card0 Nvidia appears to be adding a lot of DRM related stuff to the kernel driver (so it looks a lot like a real DRM driver to userspace now) and the modesetting DDX is getting further into its initialization. In my case, pointing the modesetting DDX to only look at non-Nvidia devices (the kmsdev option) and ensuring all the Nvidia kernel modules are fully loaded (instead of having them load on-demand) before starting X worked around this. The latter is for some weird race condition where the Nvidia driver is only partially loaded and https://gitlab.freedesktop.org/xorg/xserver/-/blob/master/config/udev.c#L135 fails, which causes modesetting to load regardless (it’s hardcoded in xf86platformAddDevice) The WARN_ON itself can still be triggered by simply opening a Nvidia primary DRM node though, e.g. with https://gitlab.freedesktop.org/mesa/drm/-/blob/master/tests/drmdevice.c, when some other DRM client like X or fbcon already has master. Because of https://patchwork.freedesktop.org/patch/367748 the Nvidia kernel driver can no longer use its internal grabOwnership to report if DRM master can be taken. https://forums.developer.nvidia.com/t/kernel-oops-on-boot-5-9-13-with-455-45-01/163751 -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1930903 Title: Frequent kernel oops related to nvidia / nv_drm_master_set To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux-restricted-modules/+bug/1930903/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
