diff options
Diffstat (limited to 'Documentation/gpu/todo.rst')
| -rw-r--r-- | Documentation/gpu/todo.rst | 61 |
1 files changed, 61 insertions, 0 deletions
diff --git a/Documentation/gpu/todo.rst b/Documentation/gpu/todo.rst index 9013ced318cb..520da44a04a6 100644 --- a/Documentation/gpu/todo.rst +++ b/Documentation/gpu/todo.rst @@ -506,6 +506,22 @@ Contact: Maxime Ripard <mripard@kernel.org>, Level: Intermediate +Convert users of of_drm_find_bridge() to of_drm_find_and_get_bridge() +--------------------------------------------------------------------- + +Taking a struct drm_bridge pointer requires getting a reference and putting +it after disposing of the pointer. Most functions returning a struct +drm_bridge pointer already call drm_bridge_get() to increment the refcount +and their users have been updated to call drm_bridge_put() when +appropriate. of_drm_find_bridge() does not get a reference and it has been +deprecated in favor of of_drm_find_and_get_bridge() which does, but some +users still need to be converted. + +Contact: Maxime Ripard <mripard@kernel.org>, + Luca Ceresoli <luca.ceresoli@bootlin.com> + +Level: Intermediate + Core refactorings ================= @@ -878,6 +894,51 @@ Contact: Christian König Level: Starter +DRM GPU Scheduler +================= + +Provide a universal successor for drm_sched_resubmit_jobs() +----------------------------------------------------------- + +drm_sched_resubmit_jobs() is deprecated. Main reason being that it leads to +reinitializing dma_fences. See that function's docu for details. The better +approach for valid resubmissions by amdgpu and Xe is (apparently) to figure out +which job (and, through association: which entity) caused the hang. Then, the +job's buffer data, together with all other jobs' buffer data currently in the +same hardware ring, must be invalidated. This can for example be done by +overwriting it. amdgpu currently determines which jobs are in the ring and need +to be overwritten by keeping copies of the job. Xe obtains that information by +directly accessing drm_sched's pending_list. + +Tasks: + +1. implement scheduler functionality through which the driver can obtain the + information which *broken* jobs are currently in the hardware ring. +2. Such infrastructure would then typically be used in + drm_sched_backend_ops.timedout_job(). Document that. +3. Port a driver as first user. +4. Document the new alternative in the docu of deprecated + drm_sched_resubmit_jobs(). + +Contact: Christian König <christian.koenig@amd.com> + Philipp Stanner <phasta@kernel.org> + +Level: Advanced + +Add locking for runqueues +------------------------- + +There is an old FIXME by Sima in include/drm/gpu_scheduler.h. It details that +struct drm_sched_rq is read at many places without any locks, not even with a +READ_ONCE. At XDC 2025 no one could really tell why that is the case, whether +locks are needed and whether they could be added. (But for real, that should +probably be locked!). Check whether it's possible to add locks everywhere, and +do so if yes. + +Contact: Philipp Stanner <phasta@kernel.org> + +Level: Intermediate + Outside DRM =========== |