[PATCH] x86_64: fix IOAPIC on Nvidia boards

Originally suggested by Zwane Mwaikumbo

Ignore all ACPI timer overrides on all Nvidia boards.  The fallback doesn't
work and no Nvidia boards needs a timer override.  But some buggy BIOS have
it anyways.

Also enable IO-APIC mode by default for Nvidia then.

Thanks to Andy Currid for confirming this.
Signed-off-by: Andi Kleen <ak@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

arch/x86_64/kernel/io_apic.c

@@ -257,12 +257,14 @@ void __init check_ioapic(void)
 #endif
 					return;
 				case PCI_VENDOR_ID_NVIDIA:
-#ifndef CONFIG_SMP
+#ifdef CONFIG_ACPI
+					/* All timer overrides on Nvidia
+				           seem to be wrong. Skip them. */
+					acpi_skip_timer_override = 1;
 					printk(KERN_INFO 
-     "PCI bridge %02x:%02x from %x found. Setting \"noapic\". Overwrite with \"apic\"\n",
-					       num,slot,vendor); 
-					skip_ioapic_setup = 1;
+	     "Nvidia board detected. Ignoring ACPI timer override.\n");
 #endif
+					/* RED-PEN skip them on mptables too? */
 					return;
 				} 
 

include/asm-x86_64/acpi.h

@@ -166,6 +166,8 @@ extern int acpi_pci_disabled;
 
 extern u8 x86_acpiid_to_apicid[];
 
+extern int acpi_skip_timer_override;
+
 #endif /*__KERNEL__*/
 
 #endif /*_ASM_ACPI_H*/