[Bug 214621] WARNING: CPU: 3 PID: 521 at drivers/gpu/drm/ttm/ttm_bo.c:409 ttm_bo_release+0xb64/0xe40 [ttm]

https://bugzilla.kernel.org/show_bug.cgi?id=214621

--- Comment #13 from Christian König (christian.koenig@amd.com) --- (In reply to Lang Yu from comment #12)

The warning was just merged into mainline 5.15.0 on Tue Nov 2 16:47:49 2021(commit 56d33754481f). Not sure Erhard F.'s build contains this warning.

Good point.

And we can also add a debug WARN() into amdgpu_dma_buf_pin() to see who pinned dma_buf.

I thought about that as well, the problem is that we call this function very often (e.g. 60 times a second if we play a 60fps video or similar).

Saying that I could as well be misguided by the dma_buf_release() function in the call stack. This could potentially also be a bug in DAL/DC where we forget to unpin a BO in some situation.