From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751819AbaC1IVq (ORCPT ); Fri, 28 Mar 2014 04:21:46 -0400 Received: from mga02.intel.com ([134.134.136.20]:8957 "EHLO mga02.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751115AbaC1IVo (ORCPT ); Fri, 28 Mar 2014 04:21:44 -0400 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="4.97,749,1389772800"; d="scan'208";a="481985536" Date: Fri, 28 Mar 2014 16:20:54 +0800 From: Feng Tang To: Ingo Molnar Cc: Clemens Ladisch , tglx@linutronix.de, mingo@elte.hu, hpa@zytor.com, linux-kernel@vger.kernel.org, John Stultz , Andy Lutomirski Subject: Re: [PATCH v2] x86: hpet: Don't default CONFIG_HPET_TIMER to be y for X86_64 Message-ID: <20140328082054.GB12762@feng-snb> References: <1395975316-4795-1-git-send-email-feng.tang@intel.com> <20140328071716.GC30107@gmail.com> <20140328073718.GA12762@feng-snb> <53352DE5.2090600@ladisch.de> <20140328081117.GA32308@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20140328081117.GA32308@gmail.com> User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, Mar 28, 2014 at 09:11:17AM +0100, Ingo Molnar wrote: > > * Clemens Ladisch wrote: > > > Feng Tang wrote: > > > On Fri, Mar 28, 2014 at 08:17:16AM +0100, Ingo Molnar wrote: > > >> * Feng Tang wrote: > > >> - or the kernel should have a quirk to reliably disable it. Why > > >> should we crash or misbehave if a driver is built into the > > >> kernel? > > > > > > I thought about this before, HPET doesn't have PCI ID like stuff, > > > > HPET does have the PCI vendor ID in the first register. > > > > > only thing I can think of to identify them may be the CPU family/ID. > > > > The HPET is implemented by some actual chip, and that chip also has lots > > of PCI devices. (In the case of a SoC, the CPU ID would work, too). > > Correct. See arch/x86/kernel/hpet.c, which has a large number of HPET > quirks keyed off chipset PCI IDs: > > DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_ESB2_0, > ich_force_enable_hpet); > DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_ICH6_0, > ich_force_enable_hpet); > DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_ICH6_1, > ich_force_enable_hpet); > [...] Got it, thanks Ingo and Clemens for the pointer. Will try to figure it out. - Feng