nvfx: nasty hack to make glFinish() actually finish..

Signed-off-by: Ben Skeggs <bskeggs@redhat.com>

src/gallium/drivers/nvfx/nvfx_context.c

@@ -24,9 +24,21 @@ nvfx_flush(struct pipe_context *pipe,
 		OUT_RING(chan, 1);
         }*/
 
-	FIRE_RING(chan);
+	if (fence) {
-	if (fence)
+		/* horrific hack to make glFinish() work in the absence of
+		 * having proper fences in nvfx.  a pending rewrite will
+		 * fix this properly, but may be a while off.
+		 */
+		MARK_RING(chan, 1, 1);
+		OUT_RELOC(chan, screen->fence, 0, NOUVEAU_BO_WR |
+				NOUVEAU_BO_DUMMY, 0, 0);
+		FIRE_RING(chan);
+		nouveau_bo_map(screen->fence, NOUVEAU_BO_RDWR);
+		nouveau_bo_unmap(screen->fence);
 		*fence = NULL;
+	} else {
+		FIRE_RING(chan);
+	}
 }
 
 static void

src/gallium/drivers/nvfx/nvfx_screen.c

@@ -304,6 +304,7 @@ nvfx_screen_destroy(struct pipe_screen *pscreen)
 	nouveau_notifier_free(&screen->sync);
 	nouveau_grobj_free(&screen->eng3d);
 	nvfx_screen_surface_takedown(pscreen);
+	nouveau_bo_ref(NULL, &screen->fence);
 
 	nouveau_screen_fini(&screen->base);
 
@@ -468,6 +469,12 @@ nvfx_screen_create(struct pipe_winsys *ws, struct nouveau_device *dev)
 	pscreen->is_format_supported = nvfx_screen_is_format_supported;
 	pscreen->context_create = nvfx_create;
 
+	ret = nouveau_bo_new(dev, NOUVEAU_BO_VRAM, 0, 4096, &screen->fence);
+	if (ret) {
+		nvfx_screen_destroy(pscreen);
+		return NULL;
+	}
+
 	switch (dev->chipset & 0xf0) {
 	case 0x30:
 		if (NV30_3D_CHIPSET_3X_MASK & (1 << (dev->chipset & 0x0f)))

src/gallium/drivers/nvfx/nvfx_screen.h

@@ -11,6 +11,7 @@ struct nvfx_screen {
 	struct nouveau_screen base;
 
 	struct nouveau_winsys *nvws;
+	struct nouveau_bo *fence;
 
 	struct nvfx_context *cur_ctx;