Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1760147AbZAWBn3 (ORCPT ); Thu, 22 Jan 2009 20:43:29 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1755203AbZAWBnU (ORCPT ); Thu, 22 Jan 2009 20:43:20 -0500 Received: from e2.ny.us.ibm.com ([32.97.182.142]:52333 "EHLO e2.ny.us.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755142AbZAWBnT (ORCPT ); Thu, 22 Jan 2009 20:43:19 -0500 Subject: Re: System clock runs too fast after 2.6.27 -> 2.6.28.1 upgrade From: john stultz To: Miklos Vajna , Florian Fainelli Cc: linux-kernel@vger.kernel.org, Thomas Gleixner , Ingo Molnar , "H. Peter Anvin" , "Rafael J. Wysocki" , Gabriel C , =?ISO-8859-1?Q?CS=C9CSY_L=E1szl=F3?= In-Reply-To: <20090122235727.GB21473@genesis.frugalware.org> References: <20090121171423.GI21473@genesis.frugalware.org> <1f1b08da0901211200l88fa89s78a51c4e90878d85@mail.gmail.com> <20090121210726.GK21473@genesis.frugalware.org> <1232573646.6997.21.camel@localhost.localdomain> <20090122195132.GZ21473@genesis.frugalware.org> <20090122235727.GB21473@genesis.frugalware.org> Content-Type: text/plain Date: Thu, 22 Jan 2009 17:43:14 -0800 Message-Id: <1232674994.6678.45.camel@localhost.localdomain> Mime-Version: 1.0 X-Mailer: Evolution 2.22.3.1 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2690 Lines: 86 On Fri, 2009-01-23 at 00:57 +0100, Miklos Vajna wrote: > On Thu, Jan 22, 2009 at 12:03:14PM -0800, john stultz > > CONFIG_X86_VISWS: If I recall, this is support for SGI workstations that > > had different apics then most systems, and might be related. > > > I just did a new build with CONFIG_X86_VISWS and CONFIG_X86_RDC321X > disabled, but I kept CONFIG_PARAVIRT_GUEST enabled and that works fine > as well. So CONFIG_PARAVIRT_GUEST seems to be unrelated. Ah. CONFIG_X86_RDC321X is indeed the issue. >From arch/x86/include/asm/timex.h: #ifdef CONFIG_X86_ELAN # define PIT_TICK_RATE 1189200 /* AMD Elan has different frequency! */ #elif defined(CONFIG_X86_RDC321X) # define PIT_TICK_RATE 1041667 /* Underlying HZ for R8610 */ #else # define PIT_TICK_RATE 1193182 /* Underlying HZ */ #endif This gives the kernel an incorrect slower frequency for the PIT hardware on your system and is why the TSC calibration is off and why the ACPI PM gets thrown out. I'd think this would ideally be more of a subarch in the config selection like the AMD Elan is, so folks know it really is not just a extra-support feature and in fact limits what hardware you can use the resulting kernel on. Florian, any thoughts on this? Would a patch like the following (untested) be ok by you? thanks -john Signed-off-by: John Stultz diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig index 862adb9..6d8ac94 100644 --- a/arch/x86/Kconfig +++ b/arch/x86/Kconfig @@ -300,6 +300,16 @@ config X86_ELAN If unsure, choose "PC-compatible" instead. +config X86_RDC321X + bool "RDC R-321x SoC" + depends on X86_32 + select M486 + select X86_REBOOTFIXUPS + help + This option is needed for RDC R-321x system-on-chip, also known + as R-8610-(G). + If you don't have one of these chips, you should say N here. + config X86_VOYAGER bool "Voyager (NCR)" depends on X86_32 && (SMP || BROKEN) && !PCI @@ -380,16 +390,6 @@ config X86_VISWS A kernel compiled for the Visual Workstation will run on general PCs as well. See for details. -config X86_RDC321X - bool "RDC R-321x SoC" - depends on X86_32 - select M486 - select X86_REBOOTFIXUPS - help - This option is needed for RDC R-321x system-on-chip, also known - as R-8610-(G). - If you don't have one of these chips, you should say N here. - config SCHED_OMIT_FRAME_POINTER def_bool y prompt "Single-depth WCHAN output" -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/