+ /* 751 Errata (22564_B-1.PDF)
+ erratum 20: strobe glitch with Nvidia NV10 GeForce cards.
+ system controller may experience noise due to strong drive strengths
+ */
+ if (agp_bridge->dev->device == PCI_DEVICE_ID_AMD_FE_GATE_7006) {
+ u8 cap_ptr=0;
+ struct pci_dev *gfxcard=NULL;
+ while (!cap_ptr) {
+ gfxcard = pci_get_class(PCI_CLASS_DISPLAY_VGA<<8, gfxcard);
+ if (!gfxcard) {
+ printk (KERN_INFO PFX "Couldn't find an AGP VGA controller.\n");
+ return -ENODEV;
+ }
+ cap_ptr = pci_find_capability(gfxcard, PCI_CAP_ID_AGP);
+ if (!cap_ptr) {
+ pci_dev_put(gfxcard);
+ continue;
+ }
+ }
+
+ /* With so many variants of NVidia cards, it's simpler just
+ to blacklist them all, and then whitelist them as needed
+ (if necessary at all). */
+ if (gfxcard->vendor == PCI_VENDOR_ID_NVIDIA) {
+ agp_bridge->flags |= AGP_ERRATA_1X;
+ printk (KERN_INFO PFX "AMD 751 chipset with NVidia GeForce detected. Forcing to 1X due to errata.\n");
+ }
+ pci_dev_put(gfxcard);
+ }
+
+ /* 761 Errata (23613_F.pdf)
+ * Revisions B0/B1 were a disaster.
+ * erratum 44: SYSCLK/AGPCLK skew causes 2X failures -- Force mode to 1X
+ * erratum 45: Timing problem prevents fast writes -- Disable fast write.
+ * erratum 46: Setup violation on AGP SBA pins - Disable side band addressing.
+ * With this lot disabled, we should prevent lockups. */
+ if (agp_bridge->dev->device == PCI_DEVICE_ID_AMD_FE_GATE_700E) {
+ u8 revision=0;
+ pci_read_config_byte(pdev, PCI_REVISION_ID, &revision);
+ if (revision == 0x10 || revision == 0x11) {
+ agp_bridge->flags = AGP_ERRATA_FASTWRITES;
+ agp_bridge->flags |= AGP_ERRATA_SBA;
+ agp_bridge->flags |= AGP_ERRATA_1X;
+ printk (KERN_INFO PFX "AMD 761 chipset with errata detected - disabling AGP fast writes & SBA and forcing to 1X.\n");
+ }
+ }
+