gallium/u_gen_mipmap: don't release vertex buffer at end of frame / in glFlush

There's no reason to do that. The buffer being used for rendering is always
mapped as unsynchronized.

src/gallium/auxiliary/util/u_gen_mipmap.c

@@ -1361,8 +1361,10 @@ get_next_slot(struct gen_mipmap_state *ctx)
 {
    const unsigned max_slots = 4096 / sizeof ctx->vertices;
 
-   if (ctx->vbuf_slot >= max_slots) 
-      util_gen_mipmap_flush( ctx );
+   if (ctx->vbuf_slot >= max_slots) {
+      pipe_resource_reference(&ctx->vbuf, NULL);
+      ctx->vbuf_slot = 0;
+   }
 
    if (!ctx->vbuf) {
       ctx->vbuf = pipe_buffer_create(ctx->pipe->screen,
@@ -1475,17 +1477,6 @@ util_destroy_gen_mipmap(struct gen_mipmap_state *ctx)
 }
 
 
-
-/* Release vertex buffer at end of frame to avoid synchronous
- * rendering.
- */
-void util_gen_mipmap_flush( struct gen_mipmap_state *ctx )
-{
-   pipe_resource_reference(&ctx->vbuf, NULL);
-   ctx->vbuf_slot = 0;
-} 
-
-
 /**
  * Generate mipmap images.  It's assumed all needed texture memory is
  * already allocated.

src/gallium/auxiliary/util/u_gen_mipmap.h

@@ -50,12 +50,6 @@ util_create_gen_mipmap(struct pipe_context *pipe, struct cso_context *cso);
 extern void
 util_destroy_gen_mipmap(struct gen_mipmap_state *ctx);
 
-/* Release vertex buffer at end of frame to avoid synchronous
- * rendering.
- */
-extern void 
-util_gen_mipmap_flush( struct gen_mipmap_state *ctx );
-
 
 extern void
 util_gen_mipmap(struct gen_mipmap_state *ctx,

src/mesa/state_tracker/st_cb_flush.c

@@ -81,11 +81,7 @@ void st_flush( struct st_context *st,
 {
    FLUSH_CURRENT(st->ctx, 0);
 
-   /* Release any vertex buffers that might potentially be accessed in
-    * successive frames:
-    */
    st_flush_bitmap(st);
-   util_gen_mipmap_flush(st->gen_mipmap);
 
    st->pipe->flush( st->pipe, fence );
 }