[RFC weston 07/14] compositor-drm: Refactor sprite create/destroy into helpers

[Daniel Stone]

From: Pekka Paalanen <pekka.paalanen at collabora.co.uk>

This moves the single sprite creation code from create_sprites() into a
new function. The readability clean-up is small, but my intention is to
write an alternate version of create_sprites(), and sharing the single
sprite creation code is useful.

[daniels: Genericised from drm_sprite to drm_plane, moving some of the
          logic back into create_sprites(), also symmetrical
	  drm_plane_destroy.]

Signed-off-by: Pekka Paalanen <pekka.paalanen at collabora.co.uk>
Signed-off-by: Daniel Stone <daniels at collabora.com>
---
 src/compositor-drm.c | 121 ++++++++++++++++++++++++++++++++++++---------------
 1 file changed, 86 insertions(+), 35 deletions(-)

diff --git a/src/compositor-drm.c b/src/compositor-drm.c
index 15ecec2..5d07955 100644
--- a/src/compositor-drm.c
+++ b/src/compositor-drm.c
@@ -2284,12 +2284,82 @@ err_free:
 	return -1;
 }
 
+/**
+ * Create a drm_plane for a hardware plane
+ *
+ * Creates one drm_plane structure for a hardware plane, and initialises its
+ * properties and formats.
+ *
+ * This function does not add the plane to the list of usable planes in Weston
+ * itself; the caller is responsible for this.
+ *
+ * Call drm_plane_destroy to clean up the plane.
+ *
+ * @param ec Compositor to create plane for
+ * @param kplane DRM plane to create
+ */
+static struct drm_plane *
+drm_plane_create(struct drm_compositor *ec, const drmModePlane *kplane)
+{
+	struct drm_plane *plane;
+
+	plane = zalloc(sizeof(*plane) + ((sizeof(uint32_t)) *
+					  kplane->count_formats));
+	if (!plane) {
+		weston_log("%s: out of memory\n", __func__);
+		return NULL;
+	}
+
+	weston_plane_init(&plane->base, &ec->base, 0, 0);
+	wl_list_init(&plane->link);
+	plane->possible_crtcs = kplane->possible_crtcs;
+	plane->plane_id = kplane->plane_id;
+	plane->current = NULL;
+	plane->next = NULL;
+	plane->compositor = ec;
+	plane->count_formats = kplane->count_formats;
+	memcpy(plane->formats, kplane->formats,
+	       kplane->count_formats * sizeof(kplane->formats[0]));
+
+	return plane;
+}
+
+/**
+ * Destroy one DRM plane
+ *
+ * Destroy a DRM plane, removing it from screen and releasing its retained
+ * buffers in the process. The counterpart to drm_plane_create.
+ *
+ * @param plane Plane to deallocate (will be freed)
+ */
+static void
+drm_plane_destroy(struct drm_plane *plane)
+{
+	drmModeSetPlane(plane->compositor->drm.fd,
+			plane->plane_id, 0 /* XXX: CRTC ID? */, 0, 0,
+			0, 0, 0, 0, 0, 0, 0, 0);
+	drm_output_release_fb(plane->output, plane->current);
+	drm_output_release_fb(plane->output, plane->next);
+	weston_plane_release(&plane->base);
+	wl_list_remove(&plane->link);
+	free(plane);
+}
+
+/**
+ * Initialise sprites (overlay planes)
+ *
+ * Walk the list of provided DRM planes, and add overlay planes.
+ *
+ * Call destroy_sprites to free these planes.
+ *
+ * @param ec Compositor to create sprites for.
+ */
 static void
 create_sprites(struct drm_compositor *ec)
 {
-	struct drm_plane *plane;
 	drmModePlaneRes *kplane_res;
 	drmModePlane *kplane;
+	struct drm_plane *drm_plane;
 	uint32_t i;
 
 	kplane_res = drmModeGetPlaneResources(ec->drm.fd);
@@ -2304,53 +2374,34 @@ create_sprites(struct drm_compositor *ec)
 		if (!kplane)
 			continue;
 
-		plane = zalloc(sizeof(*plane) + ((sizeof(uint32_t)) *
-						  kplane->count_formats));
-		if (!plane) {
-			weston_log("%s: out of memory\n",
-				__func__);
-			drmModeFreePlane(kplane);
+		drm_plane = drm_plane_create(ec, kplane);
+		drmModeFreePlane(kplane);
+		if (!drm_plane)
 			continue;
-		}
 
-		plane->possible_crtcs = kplane->possible_crtcs;
-		plane->plane_id = kplane->plane_id;
-		plane->current = NULL;
-		plane->next = NULL;
-		plane->compositor = ec;
-		plane->count_formats = kplane->count_formats;
-		memcpy(plane->formats, kplane->formats,
-		       kplane->count_formats * sizeof(kplane->formats[0]));
-		drmModeFreePlane(kplane);
-		weston_plane_init(&plane->base, &ec->base, 0, 0);
-		weston_compositor_stack_plane(&ec->base, &plane->base,
+		weston_plane_init(&drm_plane->base, &ec->base, 0, 0);
+		weston_compositor_stack_plane(&ec->base, &drm_plane->base,
 					      &ec->base.primary_plane);
-
-		wl_list_insert(&ec->sprite_list, &plane->link);
+		wl_list_insert(&ec->sprite_list, &drm_plane->link);
 	}
 
 	drmModeFreePlaneResources(kplane_res);
 }
 
+/**
+ * Clean up sprites (overlay planes)
+ *
+ * The counterpart to create_sprites.
+ *
+ * @param compositor Compositor to deallocate sprites for.
+ */
 static void
 destroy_sprites(struct drm_compositor *compositor)
 {
 	struct drm_plane *plane, *next;
-	struct drm_output *output;
 
-	output = container_of(compositor->base.output_list.next,
-			      struct drm_output, base.link);
-
-	wl_list_for_each_safe(plane, next, &compositor->sprite_list, link) {
-		drmModeSetPlane(compositor->drm.fd,
-				plane->plane_id,
-				output->crtc_id, 0, 0,
-				0, 0, 0, 0, 0, 0, 0, 0);
-		drm_output_release_fb(output, plane->current);
-		drm_output_release_fb(output, plane->next);
-		weston_plane_release(&plane->base);
-		free(plane);
-	}
+	wl_list_for_each_safe(plane, next, &compositor->sprite_list, link)
+		drm_plane_destroy(plane);
 }
 
 static int
-- 
2.4.1