meson_canvas_alloc
ret = meson_canvas_alloc(priv->canvas, &priv->canvas_id_osd1);
ret = meson_canvas_alloc(priv->canvas, &priv->canvas_id_vd1_0);
ret = meson_canvas_alloc(priv->canvas, &priv->canvas_id_vd1_1);
ret = meson_canvas_alloc(priv->canvas, &priv->canvas_id_vd1_2);
EXPORT_SYMBOL_GPL(meson_canvas_alloc);
ret = meson_canvas_alloc(sess->core->canvas, canvas_id);
int meson_canvas_alloc(struct meson_canvas *canvas, u8 *canvas_index);