Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932067AbaJWR2s (ORCPT ); Thu, 23 Oct 2014 13:28:48 -0400 Received: from mga03.intel.com ([134.134.136.65]:22833 "EHLO mga03.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753393AbaJWR2r (ORCPT ); Thu, 23 Oct 2014 13:28:47 -0400 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.04,776,1406617200"; d="scan'208";a="624127276" From: jeremy.compostella@intel.com (Compostella, Jeremy) To: "H. Peter Anvin" Cc: linux-kernel@vger.kernel.org, "Kumar P\, Mahesh" , "Afantenos\, Marie Cecile" , "Jeremy Compostell" Subject: [PATCH] x86: add the X86_FEATURE_NONSTOP_TSC_S3 cpu capability to new cpu Organization: Intel Corporation SAS - RCS Nanterre B 302 456 199 - 2 rue de Paris, 92196 Meudon Cedex, France Date: Thu, 23 Oct 2014 19:27:26 +0200 Message-ID: <87ppdik875.fsf@jcompost-MOBL1.tl.intel.com> MIME-Version: 1.0 Content-Type: text/plain Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org New Intel Atom processors (Baytrail and Cherryview), have a TSC that won't stop in S3 state, say the TSC value won't be reset to 0 after resume. This feature makes TSC a more reliable clocksource and could benefit the timekeeping code during system suspend/resume cycle. Signed-off-by: Jeremy Compostella --- arch/x86/kernel/cpu/intel.c | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-) diff --git a/arch/x86/kernel/cpu/intel.c b/arch/x86/kernel/cpu/intel.c index 1ef4562..8af195e 100644 --- a/arch/x86/kernel/cpu/intel.c +++ b/arch/x86/kernel/cpu/intel.c @@ -92,11 +92,16 @@ static void early_init_intel(struct cpuinfo_x86 *c) set_sched_clock_stable(); } - /* Penwell and Cloverview have the TSC which doesn't sleep on S3 */ + /* + * Penwell, Cloverview, Valleyview and Cherryview have the TSC + * which doesn't sleep on S3. + */ if (c->x86 == 6) { switch (c->x86_model) { case 0x27: /* Penwell */ case 0x35: /* Cloverview */ + case 0x37: /* Valleyview */ + case 0x4C: /* Cherryview */ set_cpu_cap(c, X86_FEATURE_NONSTOP_TSC_S3); break; default: -- 1.9.1 -- 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/