From 7b476affcccfc7e644541a0a719f53fc7bd34c53 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Christian=20K=C3=B6nig?= Date: Fri, 7 Oct 2022 09:51:13 +0200 Subject: [PATCH] drm/sched: add DRM_SCHED_FENCE_DONT_PIPELINE flag MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit 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: Christian König Bug: https://gitlab.freedesktop.org/drm/amd/-/issues/2113#note_1579296 Reviewed-by: Alex Deucher Acked-by: Luben Tuikov Link: https://patchwork.freedesktop.org/patch/msgid/20221014081553.114899-1-christian.koenig@amd.com --- 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 6b25b2f4f5a3..6137537aaea4 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 addb135eeea6..289a33e80639 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;