From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753863AbYDFHYN (ORCPT ); Sun, 6 Apr 2008 03:24:13 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751036AbYDFHYD (ORCPT ); Sun, 6 Apr 2008 03:24:03 -0400 Received: from ozlabs.org ([203.10.76.45]:42686 "EHLO ozlabs.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750736AbYDFHYB (ORCPT ); Sun, 6 Apr 2008 03:24:01 -0400 From: Rusty Russell To: Linus Torvalds Subject: [PATCH] Fix booting pentium+ with dodgy TSC Date: Sun, 6 Apr 2008 17:23:38 +1000 User-Agent: KMail/1.9.9 Cc: Andi Kleen , "H. Anvin" , linux-kernel@vger.kernel.org, Ingo Molnar , lguest MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit Content-Disposition: inline Message-Id: <200804061723.38766.rusty@rustcorp.com.au> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Linus please apply. Almost by definition this patch can't make things worse. We handle a broken tsc these days, so no need to panic. We clear the TSC bit when tsc_init decides it's unreliable (eg. under lguest w/ bad host TSC), leading to bogus panic. Signed-off-by: Rusty Russell diff -r 5e0a39f4d07b arch/x86/kernel/cpu/bugs.c --- a/arch/x86/kernel/cpu/bugs.c Sun Apr 06 13:40:39 2008 +1000 +++ b/arch/x86/kernel/cpu/bugs.c Sun Apr 06 17:14:12 2008 +1000 @@ -143,14 +143,6 @@ static void __init check_config(void) #endif /* - * If we configured ourselves for a TSC, we'd better have one! - */ -#ifdef CONFIG_X86_TSC - if (!cpu_has_tsc) - panic("Kernel compiled for Pentium+, requires TSC feature!"); -#endif - -/* * If we were told we had a good local APIC, check for buggy Pentia, * i.e. all B steppings and the C2 stepping of P54C when using their * integrated APIC (see 11AP erratum in "Pentium Processor