openwrt/target/linux/bcm27xx/patches-5.15/950-0906-drm-vc4-crtc-Move-the-BO-handling-out-of-common-page.patch

From e2b51ac3278847aa79089b4a1b94b8d762af0052 Mon Sep 17 00:00:00 2001
From: Maxime Ripard <maxime@cerno.tech>
Date: Mon, 2 May 2022 15:25:20 +0200
Subject: [PATCH] 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.

Signed-off-by: Maxime Ripard <maxime@cerno.tech>
---
 drivers/gpu/drm/vc4/vc4_crtc.c | 34 ++++++++++++++++++++--------------
 1 file changed, 20 insertions(+), 14 deletions(-)

--- a/drivers/gpu/drm/vc4/vc4_crtc.c
+++ b/drivers/gpu/drm/vc4/vc4_crtc.c
@@ -830,21 +830,8 @@ vc4_async_page_flip_complete(struct vc4_
 	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);
 }
@@ -853,8 +840,27 @@ static void vc4_async_page_flip_seqno_co
 {
 	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);
 }
 
 static void vc4_async_page_flip_fence_complete(struct dma_fence *fence,