lima: enable multi submit optimization

Also provide a debug option to disable it.

Reviewed-by: Vasily Khoruzhick <anarsoul@gmail.com>
Signed-off-by: Qiang Yu <yuq825@gmail.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/merge_requests/3755>

src/gallium/drivers/lima/lima_screen.c

@@ -466,6 +466,8 @@ static const struct debug_named_value debug_options[] = {
           "don't use tiled buffers" },
         { "nogrowheap",   LIMA_DEBUG_NO_GROW_HEAP,
           "disable growable heap buffer" },
+        { "singlesubmit", LIMA_DEBUG_SINGLE_SUBMIT,
+          "disable multi submit optimization" },
         { NULL }
 };
 

src/gallium/drivers/lima/lima_screen.h

@@ -41,6 +41,7 @@
 #define LIMA_DEBUG_BO_CACHE       (1 << 5)
 #define LIMA_DEBUG_NO_TILING      (1 << 6)
 #define LIMA_DEBUG_NO_GROW_HEAP   (1 << 7)
+#define LIMA_DEBUG_SINGLE_SUBMIT  (1 << 8)
 
 extern uint32_t lima_debug;
 extern int lima_ctx_num_plb;

src/gallium/drivers/lima/lima_state.c

@@ -41,8 +41,9 @@ lima_set_framebuffer_state(struct pipe_context *pctx,
 {
    struct lima_context *ctx = lima_context(pctx);
 
-   /* submit need framebuffer info, flush before change it */
-   lima_flush(ctx);
+   /* make sure there are always single submit in this context */
+   if (lima_debug & LIMA_DEBUG_SINGLE_SUBMIT)
+      lima_flush(ctx);
 
    struct lima_context_framebuffer *fb = &ctx->framebuffer;