From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756144AbZEKPDm (ORCPT ); Mon, 11 May 2009 11:03:42 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1754510AbZEKPDL (ORCPT ); Mon, 11 May 2009 11:03:11 -0400 Received: from cpsmtpm-eml102.kpnxchange.com ([195.121.3.6]:62917 "EHLO CPSMTPM-EML102.kpnxchange.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753070AbZEKPDJ (ORCPT ); Mon, 11 May 2009 11:03:09 -0400 From: Frans Pop To: Thomas Gleixner Subject: Re: [PATCH] ACPI: do not mark TSC unstable for invalid C-states Date: Mon, 11 May 2009 17:03:07 +0200 User-Agent: KMail/1.9.9 Cc: linux-kernel@vger.kernel.org, Steven Rostedt , len.brown@intel.com, mingo@elte.hu, johnstul@us.ibm.com References: <200905110226.50115.elendil@planet.nl> In-Reply-To: MIME-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit Content-Disposition: inline Message-Id: <200905111703.08645.elendil@planet.nl> X-OriginalArrivalTime: 11 May 2009 15:03:09.0185 (UTC) FILETIME=[98A02F10:01C9D249] Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Monday 11 May 2009, Thomas Gleixner wrote: > commit a71e4917dc0ebbcb5a0ecb7ca3486643c1c9a6e2 (ACPI: idle: > mark_tsc_unstable() at init-time, not run-time) marks TSC unstable > even on non affected systems. > > The reason is that the state enumeration does not check the cx->valid > flag before calling tsc_halts_in_c(), so it marks TSC unstable for any > enumerated albeit invalid C state which is known to turn off TSC. > > Check cx->valid before checking whether the TSC might become unstable. > > Signed-off-by: Thomas Gleixner Tested-by: Frans Pop Thanks Thomas.