panvk/jm: Don't force a preload if the previous batch didn't have draws

We should only force a preload after a batch split if the batch we
flush had draws, otherwise we might lose the effect of clears asked
by the user.

Signed-off-by: Boris Brezillon <boris.brezillon@collabora.com>
Reviewed-by: Lars-Ivar Hesselberg Simonsen <lars-ivar.simonsen@arm.com>
Reviewed-by: Erik Faye-Lund <erik.faye-lund@collabora.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/32540>

src/panfrost/vulkan/jm/panvk_vX_cmd_buffer.c

@@ -321,8 +321,14 @@ panvk_per_arch(CmdPipelineBarrier2)(VkCommandBuffer commandBuffer,
     * barrier flag set to true.
     */
    if (cmdbuf->cur_batch) {
+      bool preload_fb =
+         cmdbuf->cur_batch && cmdbuf->cur_batch->vtc_jc.first_tiler;
+
       panvk_per_arch(cmd_close_batch)(cmdbuf);
-      panvk_per_arch(cmd_preload_fb_after_batch_split)(cmdbuf);
+
+      if (preload_fb)
+         panvk_per_arch(cmd_preload_fb_after_batch_split)(cmdbuf);
+
       panvk_per_arch(cmd_open_batch)(cmdbuf);
    }
 }