patch-2.4.18 linux/arch/i386/kernel/pci-pc.c

• Lines: 54
• Date: Tue Feb 5 18:24:33 2002
• Orig file: linux.orig/arch/i386/kernel/pci-pc.c
• Orig date: Mon Feb 18 20:18:39 2002

diff -Naur -X /home/marcelo/lib/dontdiff linux.orig/arch/i386/kernel/pci-pc.c linux/arch/i386/kernel/pci-pc.c
@@ -1109,22 +1109,29 @@
 }
 
 /*
- * Nobody seems to know what this does. Damn.
+ * Addresses issues with problems in the memory write queue timer in
+ * certain VIA Northbridges.  This bugfix is per VIA's specifications.
  *
- * But it does seem to fix some unspecified problem
- * with 'movntq' copies on Athlons.
- *
- * VIA 8363 chipset:
- *  - bit 7 at offset 0x55: Debug (RW)
+ * VIA 8363,8622,8361 Northbridges:
+ *  - bits  5, 6, 7 at offset 0x55 need to be turned off
+ * VIA 8367 (KT266x) Northbridges:
+ *  - bits  5, 6, 7 at offset 0x95 need to be turned off
  */
-static void __init pci_fixup_via_athlon_bug(struct pci_dev *d)
+static void __init pci_fixup_via_northbridge_bug(struct pci_dev *d)
 {
 	u8 v;
-	pci_read_config_byte(d, 0x55, &v);
-	if (v & 0x80) {
-		printk("Trying to stomp on Athlon bug...\n");
-		v &= 0x7f; /* clear bit 55.7 */
-		pci_write_config_byte(d, 0x55, v);
+	int where = 0x55;
+
+	if (d->device == PCI_DEVICE_ID_VIA_8367_0) {
+		where = 0x95; /* the memory write queue timer register is 
+				 different for the kt266x's: 0x95 not 0x55 */
+	}
+
+	pci_read_config_byte(d, where, &v);
+	if (v & 0xe0) {
+		printk("Disabling VIA memory write queue: [%02x] %02x->%02x\n", where, v, v & 0x1f);
+		v &= 0x1f; /* clear bits 5, 6, 7 */
+		pci_write_config_byte(d, where, v);
 	}
 }
 
@@ -1137,7 +1144,10 @@
 	{ PCI_FIXUP_HEADER,	PCI_VENDOR_ID_SI,	PCI_DEVICE_ID_SI_5597,		pci_fixup_latency },
 	{ PCI_FIXUP_HEADER,	PCI_VENDOR_ID_SI,	PCI_DEVICE_ID_SI_5598,		pci_fixup_latency },
  	{ PCI_FIXUP_HEADER,	PCI_VENDOR_ID_INTEL,	PCI_DEVICE_ID_INTEL_82371AB_3,	pci_fixup_piix4_acpi },
-	{ PCI_FIXUP_HEADER,	PCI_VENDOR_ID_VIA,	PCI_DEVICE_ID_VIA_8363_0,	pci_fixup_via_athlon_bug },
+	{ PCI_FIXUP_HEADER,	PCI_VENDOR_ID_VIA,	PCI_DEVICE_ID_VIA_8363_0,	pci_fixup_via_northbridge_bug },
+	{ PCI_FIXUP_HEADER,	PCI_VENDOR_ID_VIA,	PCI_DEVICE_ID_VIA_8622,	        pci_fixup_via_northbridge_bug },
+	{ PCI_FIXUP_HEADER,	PCI_VENDOR_ID_VIA,	PCI_DEVICE_ID_VIA_8361,	        pci_fixup_via_northbridge_bug },
+	{ PCI_FIXUP_HEADER,	PCI_VENDOR_ID_VIA,	PCI_DEVICE_ID_VIA_8367_0,	pci_fixup_via_northbridge_bug },
 	{ 0 }
 };