From 042735df2aa5846fcabfd74c5f73877132728b25 Mon Sep 17 00:00:00 2001
From: Eric Anholt <eric@anholt.net>
Date: Tue, 9 Oct 2007 12:12:34 -0700
Subject: [PATCH] FreeBSD: don't set the MTRR if it's the default mode
 (uncacheable).

---
 src/freebsd_pci.c | 7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/src/freebsd_pci.c b/src/freebsd_pci.c
index 84a0a78..be934a8 100644
--- a/src/freebsd_pci.c
+++ b/src/freebsd_pci.c
@@ -108,8 +108,11 @@ pci_device_freebsd_map_range(struct pci_device *dev,
     mro.mo_desc = &mrd;
     mro.mo_arg[0] = MEMRANGE_SET_UPDATE;
 
-    if (ioctl(fd, MEMRANGE_SET, &mro)) {
-	fprintf(stderr, "failed to set mtrr: %s\n", strerror(errno));
+    /* No need to set an MTRR if it's the default mode. */
+    if (mrd.mr_flags != MDF_UNCACHEABLE) {
+	if (ioctl(fd, MEMRANGE_SET, &mro)) {
+	    fprintf(stderr, "failed to set mtrr: %s\n", strerror(errno));
+	}
     }
 
     close(fd);
-- 
2.11.0