From aab0cde61fc8b6295569cb9d879924afc15a2bd8 Mon Sep 17 00:00:00 2001
From: Micah Dowty <micah@vmware.com>
Date: Mon, 13 Jul 2009 23:12:04 +0000
Subject: [PATCH] To get better test coverage of the host-side DMA code,
 alternate between using Fences and legacy Sync.

---
 examples/gmr-test/main.c | 12 ++++++++++--
 1 file changed, 10 insertions(+), 2 deletions(-)

diff --git a/examples/gmr-test/main.c b/examples/gmr-test/main.c
index 6e0567c..6c50b28 100644
--- a/examples/gmr-test/main.c
+++ b/examples/gmr-test/main.c
@@ -188,8 +188,16 @@ GMR_GenericCopy(SVGAGuestPtr *dest,
 
    SVGA3D_DestroySurface(tempSurfaceId);
 
-   /* Wait for both DMA operations to finish. */
-   SVGA_SyncToFence(SVGA_InsertFence());
+   /*
+    * Wait for both DMA operations to finish. For better test
+    * coverage, we'll alternate between using fences and legacy syncs.
+    */
+   if (testIters & 1) {
+      SVGA_SyncToFence(SVGA_InsertFence());
+   } else {
+      SVGA_WriteReg(SVGA_REG_SYNC, 1);
+      while (SVGA_ReadReg(SVGA_REG_BUSY));
+   }
 }