Setting this flag on a scheduler fence prevents pipelining of jobs depending on this fence. In other words we always insert a full CPU round trip before dependen jobs are pushed to the pipeline.
Signed-off-by: Christian König christian.koenig@amd.com CC: stable@vger.kernel.org # 5.19+ --- drivers/gpu/drm/scheduler/sched_entity.c | 3 ++- include/drm/gpu_scheduler.h | 9 +++++++++ 2 files changed, 11 insertions(+), 1 deletion(-)
diff --git a/drivers/gpu/drm/scheduler/sched_entity.c b/drivers/gpu/drm/scheduler/sched_entity.c index 191c56064f19..43d337d8b153 100644 --- a/drivers/gpu/drm/scheduler/sched_entity.c +++ b/drivers/gpu/drm/scheduler/sched_entity.c @@ -385,7 +385,8 @@ static bool drm_sched_entity_add_dependency_cb(struct drm_sched_entity *entity) }
s_fence = to_drm_sched_fence(fence); - if (s_fence && s_fence->sched == sched) { + if (s_fence && s_fence->sched == sched && + !test_bit(DRM_SCHED_FENCE_DONT_PIPELINE, &fence->flags)) {
/* * Fence is from the same scheduler, only need to wait for diff --git a/include/drm/gpu_scheduler.h b/include/drm/gpu_scheduler.h index 0fca8f38bee4..f01d14b231ed 100644 --- a/include/drm/gpu_scheduler.h +++ b/include/drm/gpu_scheduler.h @@ -32,6 +32,15 @@
#define MAX_WAIT_SCHED_ENTITY_Q_EMPTY msecs_to_jiffies(1000)
+/** + * DRM_SCHED_FENCE_DONT_PIPELINE - Prefent dependency pipelining + * + * Setting this flag on a scheduler fence prevents pipelining of jobs depending + * on this fence. In other words we always insert a full CPU round trip before + * dependen jobs are pushed to the hw queue. + */ +#define DRM_SCHED_FENCE_DONT_PIPELINE DMA_FENCE_FLAG_USER_BITS + struct drm_gem_object;
struct drm_gpu_scheduler;