From f1be3d8cdde17a9b9ae283e1bab2f46b992d3bf3 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Marek=20Ol=C5=A1=C3=A1k?= <marek.olsak@amd.com>
Date: Sat, 27 Jun 2015 14:03:46 +0200
Subject: [PATCH] radeonsi: don't flush an empty IB if the only thing we need
 is a fence

Reviewed-by: Alex Deucher <alexander.deucher@amd.com>
---
 src/gallium/drivers/radeonsi/si_hw_context.c | 16 +++++++++++++---
 src/gallium/drivers/radeonsi/si_pipe.c       |  1 +
 src/gallium/drivers/radeonsi/si_pipe.h       |  1 +
 3 files changed, 15 insertions(+), 3 deletions(-)

diff --git a/src/gallium/drivers/radeonsi/si_hw_context.c b/src/gallium/drivers/radeonsi/si_hw_context.c
index 313ced7f5d1..08cc08e64fe 100644
--- a/src/gallium/drivers/radeonsi/si_hw_context.c
+++ b/src/gallium/drivers/radeonsi/si_hw_context.c
@@ -82,9 +82,15 @@ void si_context_gfx_flush(void *context, unsigned flags,
 {
 	struct si_context *ctx = context;
 	struct radeon_winsys_cs *cs = ctx->b.rings.gfx.cs;
+	struct radeon_winsys *ws = ctx->b.ws;
 
-	if (cs->cdw == ctx->b.initial_gfx_cs_size && !fence)
+	if (cs->cdw == ctx->b.initial_gfx_cs_size) {
+		if (fence)
+			ws->fence_reference(fence, ctx->last_gfx_fence);
+		if (!(flags & RADEON_FLUSH_ASYNC))
+			ws->cs_sync_flush(cs);
 		return;
+	}
 
 	ctx->b.rings.gfx.flushing = true;
 
@@ -101,9 +107,13 @@ void si_context_gfx_flush(void *context, unsigned flags,
 	flags |= RADEON_FLUSH_KEEP_TILING_FLAGS;
 
 	/* Flush the CS. */
-	ctx->b.ws->cs_flush(cs, flags, fence, ctx->screen->b.cs_count++);
+	ws->cs_flush(cs, flags, &ctx->last_gfx_fence,
+		     ctx->screen->b.cs_count++);
 	ctx->b.rings.gfx.flushing = false;
 
+	if (fence)
+		ws->fence_reference(fence, ctx->last_gfx_fence);
+
 #if SI_TRACE_CS
 	if (ctx->screen->b.trace_bo) {
 		struct si_screen *sscreen = ctx->screen;
@@ -111,7 +121,7 @@ void si_context_gfx_flush(void *context, unsigned flags,
 
 		for (i = 0; i < 10; i++) {
 			usleep(5);
-			if (!ctx->b.ws->buffer_is_busy(sscreen->b.trace_bo->buf, RADEON_USAGE_READWRITE)) {
+			if (!ws->buffer_is_busy(sscreen->b.trace_bo->buf, RADEON_USAGE_READWRITE)) {
 				break;
 			}
 		}
diff --git a/src/gallium/drivers/radeonsi/si_pipe.c b/src/gallium/drivers/radeonsi/si_pipe.c
index 77b8d7d3a6a..13b67d210fd 100644
--- a/src/gallium/drivers/radeonsi/si_pipe.c
+++ b/src/gallium/drivers/radeonsi/si_pipe.c
@@ -44,6 +44,7 @@ static void si_destroy_context(struct pipe_context *context)
 	pipe_resource_reference(&sctx->null_const_buf.buffer, NULL);
 	r600_resource_reference(&sctx->border_color_table, NULL);
 	r600_resource_reference(&sctx->scratch_buffer, NULL);
+	sctx->b.ws->fence_reference(&sctx->last_gfx_fence, NULL);
 
 	si_pm4_free_state(sctx, sctx->init_config, ~0);
 	si_pm4_delete_state(sctx, gs_rings, sctx->gs_rings);
diff --git a/src/gallium/drivers/radeonsi/si_pipe.h b/src/gallium/drivers/radeonsi/si_pipe.h
index 2d67342f160..67cb0357231 100644
--- a/src/gallium/drivers/radeonsi/si_pipe.h
+++ b/src/gallium/drivers/radeonsi/si_pipe.h
@@ -137,6 +137,7 @@ struct si_context {
 	void				*pstipple_sampler_state;
 	struct si_screen		*screen;
 	struct si_pm4_state		*init_config;
+	struct pipe_fence_handle	*last_gfx_fence;
 
 	union {
 		struct {