On Fri, Sep 17, 2021 at 02:35:08PM +0200, Christian König wrote:
Makes the handling a bit more complex, but avoids the use of dma_resv_get_excl_unlocked().
v2: add missing rcu_read_lock()/unlock()
Signed-off-by: Christian König christian.koenig@amd.com
drivers/gpu/drm/drm_gem_atomic_helper.c | 14 ++++++++++++-- 1 file changed, 12 insertions(+), 2 deletions(-)
diff --git a/drivers/gpu/drm/drm_gem_atomic_helper.c b/drivers/gpu/drm/drm_gem_atomic_helper.c index e570398abd78..d8f9c6432544 100644 --- a/drivers/gpu/drm/drm_gem_atomic_helper.c +++ b/drivers/gpu/drm/drm_gem_atomic_helper.c @@ -143,6 +143,7 @@ */ int drm_gem_plane_helper_prepare_fb(struct drm_plane *plane, struct drm_plane_state *state) {
- struct dma_resv_iter cursor; struct drm_gem_object *obj; struct dma_fence *fence;
@@ -150,9 +151,18 @@ int drm_gem_plane_helper_prepare_fb(struct drm_plane *plane, struct drm_plane_st return 0; obj = drm_gem_fb_get_obj(state->fb, 0);
- fence = dma_resv_get_excl_unlocked(obj->resv);
- drm_atomic_set_fence_for_plane(state, fence);
- rcu_read_lock();
- dma_resv_iter_begin(&cursor, obj->resv, false);
- dma_resv_for_each_fence_unlocked(&cursor, fence) {
rcu_read_unlock();/* TODO: We only use the first write fence here */drm_atomic_set_fence_for_plane(state, fence);
Yeah I wonder whether we should/need to collate them all together. But I guesss whomever hits that first with their funny multi-plane yuv or whatever gets to do that. Or I'm not clear on what exactly your TODO here means?
return 0;- }
- dma_resv_iter_end(&cursor);
- rcu_read_unlock();
Imo we should do full dma_resv_lock here. atomic helpers are designed to allow this, and it simplifies things. Also it really doesn't matter for atomic, we should be able to do 60fps*a few planes easily :-) -Daniel
- drm_atomic_set_fence_for_plane(state, NULL); return 0;
} EXPORT_SYMBOL_GPL(drm_gem_plane_helper_prepare_fb); -- 2.25.1