[PATCH] Enable write combining for server works LE rev > 6
Enable write combining for server works LE rev > 6 per
http://www.ussg.iu.edu/hypermail/linux/kernel/0104.3/1007.html
Signed-Off-By: Lee Revell <rlrevell@joe-job.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
diff --git a/arch/i386/kernel/cpu/mtrr/main.c b/arch/i386/kernel/cpu/mtrr/main.c
index 54999e4..e1c2042 100644
--- a/arch/i386/kernel/cpu/mtrr/main.c
+++ b/arch/i386/kernel/cpu/mtrr/main.c
@@ -72,17 +72,21 @@
static int have_wrcomb(void)
{
struct pci_dev *dev;
+ u8 rev;
if ((dev = pci_get_class(PCI_CLASS_BRIDGE_HOST << 8, NULL)) != NULL) {
- /* ServerWorks LE chipsets have problems with write-combining
+ /* ServerWorks LE chipsets < rev 6 have problems with write-combining
Don't allow it and leave room for other chipsets to be tagged */
if (dev->vendor == PCI_VENDOR_ID_SERVERWORKS &&
dev->device == PCI_DEVICE_ID_SERVERWORKS_LE) {
- printk(KERN_INFO "mtrr: Serverworks LE detected. Write-combining disabled.\n");
- pci_dev_put(dev);
- return 0;
+ pci_read_config_byte(dev, PCI_CLASS_REVISION, &rev);
+ if (rev <= 5) {
+ printk(KERN_INFO "mtrr: Serverworks LE rev < 6 detected. Write-combining disabled.\n");
+ pci_dev_put(dev);
+ return 0;
+ }
}
- /* Intel 450NX errata # 23. Non ascending cachline evictions to
+ /* Intel 450NX errata # 23. Non ascending cacheline evictions to
write combining memory may resulting in data corruption */
if (dev->vendor == PCI_VENDOR_ID_INTEL &&
dev->device == PCI_DEVICE_ID_INTEL_82451NX) {