Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1423108AbWJ0HDW (ORCPT ); Fri, 27 Oct 2006 03:03:22 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1423758AbWJ0HDW (ORCPT ); Fri, 27 Oct 2006 03:03:22 -0400 Received: from styx.suse.cz ([82.119.242.94]:26324 "EHLO mail.suse.cz") by vger.kernel.org with ESMTP id S1423108AbWJ0HDV (ORCPT ); Fri, 27 Oct 2006 03:03:21 -0400 Date: Fri, 27 Oct 2006 09:03:19 +0200 From: Vojtech Pavlik To: Mika =?iso-8859-1?Q?Penttil=E4?= Cc: Andi Kleen , Om Narasimhan , "Pallipadi, Venkatesh" , linux-kernel@vger.kernel.org, randy.dunlap@oracle.com, clemens@ladisch.de, bob.picco@hp.com Subject: Re: HPET : Legacy Routing Replacement Enable - 3rd try. Message-ID: <20061027070319.GA24559@suse.cz> References: <6b4e42d10610251420x4365b840sa3232010e7bd7f73@mail.gmail.com> <20061027024238.GC58088@muc.de> <20061027055708.GA20270@suse.cz> <4541A758.9010504@kolumbus.fi> Mime-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <4541A758.9010504@kolumbus.fi> X-Bounce-Cookie: It's a lemon tree, dear Watson! User-Agent: Mutt/1.5.6i Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1578 Lines: 36 On Fri, Oct 27, 2006 at 09:29:44AM +0300, Mika Penttil? wrote: > >JFYI: The new per-cpu timekeeping code doesn't need the HPET legacy bit, > >thus not replacing IRQ0 (PIT) and IRQ13 (RTC). It still can do that, but > >will work just as well without it. > There seems to be lot of confusion here. Current code isn't using hpet > as tick source if legacy is not supported. This patch adds > hpet_lrr_force but it's not clear how it interacts with hpet_use_timer - > in some places it is hpet_use_timer and some (hpet_use_timer && > hpet_lrr_force). Sorry about my share of confusion introduced: Jiri Bohac (jbohac@suse.cz) is currently working on a new timekeeping code for x86-64 that takes a significantly different approach that allows for precise and fast gettimeofday even on CPUs with unsynchronized TSCs. This rewrite depends even less on hpet_use_timer than the current code. The current code can cope with hpet_use_timer == 0, but that mode of operation is far from optimal. > The timer is routed to ioapic pin 2 which is irq0 with source override. > With this patch with hpet_lrr_force=1 timer irq is set to 2 for x86_64 > and 0 for i386, that can't be right? It doesn't seem right to me, unless someone at Sun really misread the specification when designing the mainboard. -- Vojtech Pavlik Director SuSE Labs - 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/