[PATCH v9 14/42] drm/msm: Convert vm locking

[Rob Clark]

On Tue, Aug 12, 2025 at 1:58 AM Danilo Krummrich <kernel at dakr.org> wrote:
>
> On 6/29/25 10:12 PM, Rob Clark wrote:
> > +     /*
> > +      * We mostly want to use DRM_GPUVM_RESV_PROTECTED, except that
> > +      * makes drm_gpuvm_bo_evict() a no-op for extobjs (ie. we loose
> > +      * tracking that an extobj is evicted) :facepalm:
> > +      */
>
> Yeah, it's a consequence of this locking scheme and I really hate it. However,
> you don't entirely loose tracking:
>
> The next time you call drm_gpuvm_prepare_objects() it will be added to the list
> [1] and hence picked up by subsequent validation through drm_gpuvm_validate().
>
> [1] https://elixir.bootlin.com/linux/v6.16/source/drivers/gpu/drm/drm_gpuvm.c#L1154

Hmm, maybe the issue was with legacy (non-vm_bind) contexts, which use
drm_exec directly for locking?  I guess I can try to revisit that..

BR,
-R