Commit 03e7ac67 authored by Thomas Zimmermann's avatar Thomas Zimmermann
Browse files

drm/cirrus: Enable damage clipping on primary plane 



Enable damage clipping on the primary plane and iterate over small
areas of reported framebuffer damage. Avoid the overhead of permanent
full-screen updates that cirrus currently implements.

This problem is indicated by the warning

  drm_plane_enable_fb_damage_clips() not called

in the kernel's log. Without damage clipping, drivers do full updates
of the screen area. This is costly as many screen updates, such as
cursor movement or command-line input, only change a small portion
of the output. Damage clipping allows renderers to inform drivers about
the changed areas.

With the damage information known, cirrus now iterates over a list of
change areas and only flushes those to the hardware's scanout buffer.

Signed-off-by: default avatarThomas Zimmermann <tzimmermann@suse.de>
Acked-by: default avatarGerd Hoffmann <kraxel@redhat.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20230215161517.5113-10-tzimmermann@suse.de
parent d99c0289

drivers/gpu/drm/tiny/cirrus.c

+7 −3
Original line number Diff line number Diff line
@@ -393,7 +393,8 @@ static void cirrus_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;

	struct drm_atomic_helper_damage_iter iter;

	struct drm_rect damage;

	int idx;



	if (!fb)
@@ -407,8 +408,10 @@ static void cirrus_primary_plane_helper_atomic_update(struct drm_plane *plane, 
	if (cirrus->pitch != cirrus_pitch(fb))

		cirrus_pitch_set(cirrus, fb);



	if (drm_atomic_helper_damage_merged(old_plane_state, plane_state, &rect))

		cirrus_fb_blit_rect(fb, &shadow_plane_state->data[0], &rect);

	drm_atomic_helper_damage_iter_init(&iter, old_plane_state, plane_state);

	drm_atomic_for_each_plane_damage(&iter, &damage) {

		cirrus_fb_blit_rect(fb, &shadow_plane_state->data[0], &damage);

	}



	drm_dev_exit(idx);

}
@@ -529,6 +532,7 @@ static int cirrus_pipe_init(struct cirrus_device *cirrus) 
	if (ret)

		return ret;

	drm_plane_helper_add(primary_plane, &cirrus_primary_plane_helper_funcs);

	drm_plane_enable_fb_damage_clips(primary_plane);



	crtc = &cirrus->crtc;

	ret = drm_crtc_init_with_planes(dev, crtc, primary_plane, NULL,