From 85059964307c3f10e4a328d82af2bb791a5a4927 Mon Sep 17 00:00:00 2001
From: =?utf8?q?Marek=20Ol=C5=A1=C3=A1k?= <maraeo@gmail.com>
Date: Sat, 23 Jan 2010 17:19:44 +0100
Subject: [PATCH] radeong: do not emit a zero-sized command stream

Fixing a hardlock introduced in fcbd285e421903ee0a65f19f5d633b25b5923c24 and
reproducible with piglit/bugs/fdo23489.
---
 src/gallium/winsys/drm/radeon/core/radeon_r300.c | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/src/gallium/winsys/drm/radeon/core/radeon_r300.c b/src/gallium/winsys/drm/radeon/core/radeon_r300.c
index 0875ee41cbf..0253bc2527e 100644
--- a/src/gallium/winsys/drm/radeon/core/radeon_r300.c
+++ b/src/gallium/winsys/drm/radeon/core/radeon_r300.c
@@ -108,6 +108,11 @@ static void radeon_flush_cs(struct radeon_winsys* winsys)
 {
     int retval;
 
+    /* Don't flush a zero-sized CS. */
+    if (!winsys->priv->cs->cdw) {
+        return;
+    }
+
     /* Emit the CS. */
     retval = radeon_cs_emit(winsys->priv->cs);
     if (retval) {
-- 
2.30.2