[PATCH 10/16] drm/udl: Use damage iterator

[Thomas Zimmermann <tzimmermann@xxxxxxx>]

Use a damage iterator to process damage areas individually. Merging
damage areas can resul tin large updates of unchanged framebuffer
regions. As USB is rather slow, it's better to process damage areas
individually and hence minimize USB-transfered data.

Signed-off-by: Thomas Zimmermann <tzimmermann@xxxxxxx>
---
 drivers/gpu/drm/udl/udl_modeset.c | 38 +++++++++++++++----------------
 1 file changed, 19 insertions(+), 19 deletions(-)

diff --git a/drivers/gpu/drm/udl/udl_modeset.c b/drivers/gpu/drm/udl/udl_modeset.c
index aaa828034a04..6fa4c8b5c2c6 100644
--- a/drivers/gpu/drm/udl/udl_modeset.c
+++ b/drivers/gpu/drm/udl/udl_modeset.c
@@ -238,15 +238,9 @@ static int udl_handle_damage(struct drm_framebuffer *fb,
 		return ret;
 	log_bpp = ret;
 
-	ret = drm_gem_fb_begin_cpu_access(fb, DMA_FROM_DEVICE);
-	if (ret)
-		return ret;
-
 	urb = udl_get_urb(dev);
-	if (!urb) {
-		ret = -ENOMEM;
-		goto out_drm_gem_fb_end_cpu_access;
-	}
+	if (!urb)
+		return -ENOMEM;
 	cmd = urb->transfer_buffer;
 
 	for (i = clip->y1; i < clip->y2; i++) {
@@ -258,7 +252,7 @@ static int udl_handle_damage(struct drm_framebuffer *fb,
 				       &cmd, byte_offset, dev_byte_offset,
 				       byte_width);
 		if (ret)
-			goto out_drm_gem_fb_end_cpu_access;
+			return ret;
 	}
 
 	if (cmd > (char *)urb->transfer_buffer) {
@@ -272,11 +266,7 @@ static int udl_handle_damage(struct drm_framebuffer *fb,
 		udl_urb_completion(urb);
 	}
 
-	ret = 0;
-
-out_drm_gem_fb_end_cpu_access:
-	drm_gem_fb_end_cpu_access(fb, DMA_FROM_DEVICE);
-	return ret;
+	return 0;
 }
 
 /*
@@ -301,16 +291,26 @@ static void udl_primary_plane_helper_atomic_update(struct drm_plane *plane,
 	struct drm_shadow_plane_state *shadow_plane_state = to_drm_shadow_plane_state(plane_state);
 	struct drm_framebuffer *fb = plane_state->fb;
 	struct drm_plane_state *old_plane_state = drm_atomic_get_old_plane_state(state, plane);
-	struct drm_rect rect;
-	int idx;
+	struct drm_atomic_helper_damage_iter iter;
+	struct drm_rect damage;
+	int ret, idx;
 
-	if (!drm_dev_enter(dev, &idx))
+	ret = drm_gem_fb_begin_cpu_access(fb, DMA_FROM_DEVICE);
+	if (ret)
 		return;
 
-	if (drm_atomic_helper_damage_merged(old_plane_state, plane_state, &rect))
-		udl_handle_damage(fb, &shadow_plane_state->data[0], &rect);
+	if (!drm_dev_enter(dev, &idx))
+		goto out_drm_gem_fb_end_cpu_access;
+
+	drm_atomic_helper_damage_iter_init(&iter, old_plane_state, plane_state);
+	drm_atomic_for_each_plane_damage(&iter, &damage) {
+		udl_handle_damage(fb, &shadow_plane_state->data[0], &damage);
+	}
 
 	drm_dev_exit(idx);
+
+out_drm_gem_fb_end_cpu_access:
+	drm_gem_fb_end_cpu_access(fb, DMA_FROM_DEVICE);
 }
 
 static void udl_primary_plane_helper_atomic_disable(struct drm_plane *plane,
-- 
2.37.3