Discuss Bug 289320 - graphics/drm-66-kmod: Page fault on 16-CURRENT
Date: Sat, 06 Sep 2025 14:21:06 UTC
Hi, I'd like to open up discussion about a weird bug I stumbled across on Thursday. You can get the gory details, including backtrace in PR/289320. Long story short, after the FreeBSD version bump from 15 to 16 amdgpu panics on a kernel page fault. For fun I reverted, locally, the commit that updated the version strings in FreeBSD-CURRENT from 15 to 16, reverting 8b4e4c2737305df8807abc6cd054a32586085c93 on that particular machine, a Framework 13 laptop. The panic was solved. My other machines don't use amdgpu, they either don't use X or in the case of my HP 840, it uses the i915 driver (also part of drm-66-kmod), which works after the 15 to 16 version bump. But the 15 to 16 version bump causes amdgpu also from drm-66-kmod to reference a NULL pointer. What in drm-66-kmod would be sensitive to a FreeBSD version bump? -- Cheers, Cy Schubert <Cy.Schubert@cschubert.com> FreeBSD UNIX: <cy@FreeBSD.org> Web: https://FreeBSD.org NTP: <cy@nwtime.org> Web: https://nwtime.org e**(i*pi)+1=0