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charset=iso-8859-1 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <20210917123513.1106-22-christian.koenig@amd.com> X-Operating-System: Linux phenom 5.10.0-8-amd64 Precedence: bulk List-ID: X-Mailing-List: linux-media@vger.kernel.org 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 > --- > 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 > -- Daniel Vetter Software Engineer, Intel Corporation http://blog.ffwll.ch