Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758784AbZFONK1 (ORCPT ); Mon, 15 Jun 2009 09:10:27 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1750796AbZFONKQ (ORCPT ); Mon, 15 Jun 2009 09:10:16 -0400 Received: from mx-out2.daemonmail.net ([216.104.160.39]:33552 "EHLO mx-out2.daemonmail.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751689AbZFONKP (ORCPT ); Mon, 15 Jun 2009 09:10:15 -0400 From: "Michael S. Zick" Reply-To: lkml@morethan.org To: Linux Kernel Mailing List Subject: TSC features, was: Re: [PATCH 1/2] CPUFREQ: Enable acpi-cpufreq driver for VIA/Centaur CPUs Date: Mon, 15 Jun 2009 08:10:13 -0500 User-Agent: KMail/1.9.9 Cc: Harald Welte , Dave Jones , Linus Torvalds References: <20090608102754.GP4106@prithivi.gnumonks.org> In-Reply-To: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Content-Disposition: inline Message-Id: <200906150810.15799.lkml@morethan.org> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2529 Lines: 71 On Mon June 8 2009, Linus Torvalds wrote: > > On Mon, 8 Jun 2009, Harald Welte wrote: > > > > The VIA/Centaur C7, C7-M and Nano CPU's all support ACPI based cpu p-states > > using a MSR interface. The Linux driver just never made use of it, since in > > addition to the check for the EST flag it also checked if the vendor is Intel. > > > > Signed-off-by: Harald Welte > > --- > > arch/x86/kernel/cpu/cpufreq/acpi-cpufreq.c | 3 ++- > > 1 files changed, 2 insertions(+), 1 deletions(-) > > > > diff --git a/arch/x86/kernel/cpu/cpufreq/acpi-cpufreq.c b/arch/x86/kernel/cpu/cpufreq/acpi-cpufreq.c > > index 208ecf6..ee03585 100644 > > --- a/arch/x86/kernel/cpu/cpufreq/acpi-cpufreq.c > > +++ b/arch/x86/kernel/cpu/cpufreq/acpi-cpufreq.c > > @@ -90,7 +90,8 @@ static int check_est_cpu(unsigned int cpuid) > > { > > struct cpuinfo_x86 *cpu = &cpu_data(cpuid); > > > > - if (cpu->x86_vendor != X86_VENDOR_INTEL || > > + if ((cpu->x86_vendor != X86_VENDOR_INTEL && > > + cpu->x86_vendor != X86_VENDOR_CENTAUR) || > > !cpu_has(cpu, X86_FEATURE_EST)) > > Hmm. This all really should be just > > static int check_est_cpu(unsigned int cpuid) > { > struct cpuinfo_x86 *cpu = &cpu_data(cpuid); > return cpu_has(cpu, X86_FEATURE_EST); > } > > I suspect, with no vendor tests. That's the whole _point_ of CPU features, > after all. > Following that same logic, shouldn't this chunk be based on CPU features also? (Spotted while tracking down why the non-stop TSC wasn't being used on VIA): #if defined (CONFIG_GENERIC_TIME) && defined (CONFIG_X86) static void tsc_check_state(int state) { switch (boot_cpu_data.x86_vendor) { case X86_VENDOR_AMD: case X86_VENDOR_INTEL: /* * AMD Fam10h TSC will tick in all * C/P/S0/S1 states when this bit is set. */ if (boot_cpu_has(X86_FEATURE_NONSTOP_TSC)) return; /*FALL THROUGH*/ default: /* TSC could halt in idle, so notify users */ if (state > ACPI_STATE_C1) mark_tsc_unstable("TSC halts in idle"); } } #else static void tsc_check_state(int state) { return; } #endif Mike -- 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/