diff options
| author | Daniel Vetter <daniel.vetter@ffwll.ch> | 2021-05-19 10:24:09 +0200 |
|---|---|---|
| committer | Daniel Vetter <daniel.vetter@ffwll.ch> | 2021-05-20 22:28:11 +0200 |
| commit | 6d0a12c734c302eead11366856aecdae54a401e8 (patch) | |
| tree | ebe6aee670ce026869a0d9deeaa5d75b3d1ac2a5 /drivers/gpu/drm/ttm | |
| parent | ea8c9ed53f871ac90659fe519c85b8f10a51677d (diff) | |
drm/ttm: Explain why ttm_bo_add_move_fence uses a shared slot
Motivated because I got confused and Christian confirmed why this
works. I think this is non-obvious enough that it merits a slightly
longer comment.
Acked-by: Huang Rui <ray.huang@amd.com>
Reviewed-by: Christian König <christian.koenig@amd.com>
Cc: Christian König <ckoenig.leichtzumerken@gmail.com>
Cc: Christian Koenig <christian.koenig@amd.com>
Cc: Huang Rui <ray.huang@amd.com>
Cc: Thomas Hellström <thomas.hellstrom@linux.intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20210519082409.672016-1-daniel.vetter@ffwll.ch
Diffstat (limited to 'drivers/gpu/drm/ttm')
| -rw-r--r-- | drivers/gpu/drm/ttm/ttm_bo.c | 4 |
1 files changed, 3 insertions, 1 deletions
diff --git a/drivers/gpu/drm/ttm/ttm_bo.c b/drivers/gpu/drm/ttm/ttm_bo.c index ca1b098b6a56..51a94fd63bd7 100644 --- a/drivers/gpu/drm/ttm/ttm_bo.c +++ b/drivers/gpu/drm/ttm/ttm_bo.c @@ -682,7 +682,9 @@ int ttm_mem_evict_first(struct ttm_device *bdev, } /* - * Add the last move fence to the BO and reserve a new shared slot. + * Add the last move fence to the BO and reserve a new shared slot. We only use + * a shared slot to avoid unecessary sync and rely on the subsequent bo move to + * either stall or use an exclusive fence respectively set bo->moving. */ static int ttm_bo_add_move_fence(struct ttm_buffer_object *bo, struct ttm_resource_manager *man, |