if (job->sync)
done_fence = dma_fence_get(job->done_fence);
+ /* If a sched job depends on a dma-fence from a job from the same GPU
+ * scheduler instance, but a different scheduler entity, the GPU
+ * scheduler does only wait for the particular job to be scheduled,
+ * rather than for the job to fully complete. This is due to the GPU
+ * scheduler assuming that there is a scheduler instance per ring.
+ * However, the current implementation, in order to avoid arbitrary
+ * amounts of kthreads, has a single scheduler instance while scheduler
+ * entities represent rings.
+ *
+ * As a workaround, set the DRM_SCHED_FENCE_DONT_PIPELINE for all
+ * out-fences in order to force the scheduler to wait for full job
+ * completion for dependent jobs from different entities and same
+ * scheduler instance.
+ *
+ * There is some work in progress [1] to address the issues of firmware
+ * schedulers; once it is in-tree the scheduler topology in Nouveau
+ * should be re-worked accordingly.
+ *
+ * [1] https://lore.kernel.org/dri-devel/20230801205103.627779-1-matthew.brost@intel.com/
+ */
+ set_bit(DRM_SCHED_FENCE_DONT_PIPELINE, &job->done_fence->flags);
+
if (job->ops->armed_submit)
job->ops->armed_submit(job);