[Bug 237544] graphics/drm-fbsd12.0-kmod: panic on 12-STABLE with Radeon HD 7450 (but not with drm-fbsd11.2-kmod)

https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=237544

Bill Paul <[email protected]> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |[email protected]

--- Comment #6 from Bill Paul <[email protected]> ---
Unfortunately, this bug is still present, even using FreeBSD 12.3-RELEASE.

Note that I have observed it with several Radeon cards, so it doesn't appear
specific to a particular card. The same problem does not happen with the Intel
i915kms.ko driver from the same package.

Based on the hint here, I created my own drm-fbsd11.2-kmod port (the original
has been deleted from the repo as obsolete) and massaged it a bit to compile on
FreeBSD 12.3, and that version works without crashing.

I suspect there is a locking problem somewhere in the drm or ttm modules in the
newer code. Sadly, nobody seems to care enough to fix it. (And I don't
understand the code well enough to fix it myself. The differences between the
4.11 and 4.16 versions of the driver are substantial.)

-- 
You are receiving this mail because:
You are the assignee for the bug.