drm/vc4: crtc: Move the BO handling out of common page-flip callback

We'll soon introduce another completion callback source that won't need
to use the BO reference counting, so let's move it around to create a
function we will be able to share between both callbacks.

Reviewed-by: Melissa Wen <mwen@igalia.com>
Signed-off-by: Maxime Ripard <maxime@cerno.tech>
Link: https://lore.kernel.org/r/20220610115149.964394-11-maxime@cerno.tech

diff --git a/drivers/gpu/drm/vc4/vc4_crtc.c b/drivers/gpu/drm/vc4/vc4_crtc.c
index 1f247c0..0410db9 100644 (file)
--- a/drivers/gpu/drm/vc4/vc4_crtc.c
+++ b/drivers/gpu/drm/vc4/vc4_crtc.c
@@ -802,21 +802,8 @@ vc4_async_page_flip_complete(struct vc4_async_flip_state *flip_state)
        drm_crtc_vblank_put(crtc);
        drm_framebuffer_put(flip_state->fb);
 
-       /* Decrement the BO usecnt in order to keep the inc/dec calls balanced
-        * when the planes are updated through the async update path.
-        * FIXME: we should move to generic async-page-flip when it's
-        * available, so that we can get rid of this hand-made cleanup_fb()
-        * logic.
-        */
-       if (flip_state->old_fb) {
-               struct drm_gem_cma_object *cma_bo;
-               struct vc4_bo *bo;
-
-               cma_bo = drm_fb_cma_get_gem_obj(flip_state->old_fb, 0);
-               bo = to_vc4_bo(&cma_bo->base);
-               vc4_bo_dec_usecnt(bo);
+       if (flip_state->old_fb)
                drm_framebuffer_put(flip_state->old_fb);
-       }
 
        kfree(flip_state);
 }
@@ -825,8 +812,27 @@ static void vc4_async_page_flip_seqno_complete(struct vc4_seqno_cb *cb)
 {
        struct vc4_async_flip_state *flip_state =
                container_of(cb, struct vc4_async_flip_state, cb.seqno);
+       struct vc4_bo *bo = NULL;
+
+       if (flip_state->old_fb) {
+               struct drm_gem_cma_object *cma_bo =
+                       drm_fb_cma_get_gem_obj(flip_state->old_fb, 0);
+               bo = to_vc4_bo(&cma_bo->base);
+       }
 
        vc4_async_page_flip_complete(flip_state);
+
+       /*
+        * Decrement the BO usecnt in order to keep the inc/dec
+        * calls balanced when the planes are updated through
+        * the async update path.
+        *
+        * FIXME: we should move to generic async-page-flip when
+        * it's available, so that we can get rid of this
+        * hand-made cleanup_fb() logic.
+        */
+       if (bo)
+               vc4_bo_dec_usecnt(bo);
 }
 
 /* Implements async (non-vblank-synced) page flips.