f32ac20862
iris uses u_default_buffer_subdata for buffer uploads via a CPU map so clearing shouldn't be substantially worse. We can do it with BLORP in the future if we decide it's useful. [Alyssa: A BLORP implementation is available at https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/15931 however nobody has taken to reviewing that solution.] Reviewed-by: Alyssa Rosenzweig <alyssa@collabora.com> Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/16044>