From: Ingo Molnar Date: Mon, 26 Nov 2007 19:42:20 +0000 (+0100) Subject: x86: fix APIC related bootup crash on Athlon XP CPUs X-Git-Tag: v4.13~33384^2 X-Git-Url: https://git.proxmox.com/?a=commitdiff_plain;h=f44d9efd3510776216938fef84adc99cc0e12412;p=mirror_ubuntu-bionic-kernel.git x86: fix APIC related bootup crash on Athlon XP CPUs warmbloodedcreature@gmail.com reported that an APIC-enabled Asus a7v8x-x with an Athlon XP reboots early in the bootup: http://bugzilla.kernel.org/show_bug.cgi?id=8723 after a long marathon of spontaneous-reboot debugging, it turns out to be caused by sync_Arb_ids(). AMD CPUs never really needed this sequence anyway, so just return early if we meet an AMD CPU. Signed-off-by: Ingo Molnar Signed-off-by: Thomas Gleixner --- diff --git a/arch/x86/kernel/apic_32.c b/arch/x86/kernel/apic_32.c index 08b07c176962..96986b46bc85 100644 --- a/arch/x86/kernel/apic_32.c +++ b/arch/x86/kernel/apic_32.c @@ -789,7 +789,7 @@ void __init sync_Arb_IDs(void) * Unsupported on P4 - see Intel Dev. Manual Vol. 3, Ch. 8.6.1 And not * needed on AMD. */ - if (modern_apic()) + if (modern_apic() || boot_cpu_data.x86_vendor == X86_VENDOR_AMD) return; /* * Wait for idle.