Re: PCI MSI breaks when booting with nosmp

[Jesse Barnes <jbarnes@virtuousgeek.org>]

On Monday, April 21, 2008 2:09 pm Andi Kleen wrote:
> > Both call disable_ioapic_setup(), so how can they not be the same?
>
> See Jesse's explanation. Basically there is special code in the smp
> boot up to handle 0 CPUs and it disables all APICs.
>
> This is very old and crufty and somewhat obsolete logic,
> but it is like that.

This might be closer to a real fix.  Can you confirm that this works for you 
Jean?

Thanks,
Jesse

diff --git a/arch/x86/kernel/smpboot.c b/arch/x86/kernel/smpboot.c
index e6abe8a..7cdf930 100644
--- a/arch/x86/kernel/smpboot.c
+++ b/arch/x86/kernel/smpboot.c
@@ -1138,14 +1138,10 @@ static int __init smp_sanity_check(unsigned max_cpus)
 				 "forcing use of dummy APIC emulation.\n");
 		smpboot_clear_io_apic();
 #ifdef CONFIG_X86_32
-		if (nmi_watchdog == NMI_LOCAL_APIC) {
-			printk(KERN_INFO "activating minimal APIC for"
-					 "NMI watchdog use.\n");
-			connect_bsp_APIC();
-			setup_local_APIC();
-			end_local_APIC_setup();
-		}
+		connect_bsp_APIC();
 #endif
+		setup_local_APIC();
+		end_local_APIC_setup();
 		return -1;
 	}