Commit 7b476aff authored by Christian König's avatar Christian König
Browse files

drm/sched: add DRM_SCHED_FENCE_DONT_PIPELINE flag 



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 dependent jobs are pushed to the pipeline.

Signed-off-by: default avatarChristian König <christian.koenig@amd.com>
Bug: https://gitlab.freedesktop.org/drm/amd/-/issues/2113#note_1579296


Reviewed-by: default avatarAlex Deucher <alexander.deucher@amd.com>
Acked-by: default avatarLuben Tuikov <luben.tuikov@amd.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20221014081553.114899-1-christian.koenig@amd.com
parent 4190e8bb

drivers/gpu/drm/scheduler/sched_entity.c

+2 −1
Original line number Diff line number Diff line
@@ -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

include/drm/gpu_scheduler.h

+9 −0
Original line number Diff line number Diff line
@@ -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;