Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S268132AbUIPSV7 (ORCPT ); Thu, 16 Sep 2004 14:21:59 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S268113AbUIPSTQ (ORCPT ); Thu, 16 Sep 2004 14:19:16 -0400 Received: from twilight.ucw.cz ([81.30.235.3]:16276 "EHLO ucw.cz") by vger.kernel.org with ESMTP id S268161AbUIPSRb (ORCPT ); Thu, 16 Sep 2004 14:17:31 -0400 Date: Thu, 16 Sep 2004 20:17:08 +0200 From: Vojtech Pavlik To: Bjorn Helgaas Cc: Christoph Lameter , linux-kernel@vger.kernel.org, Jesse Barnes , Bob Picco , venkatesh.pallipadi@intel.com Subject: Re: device driver for the SGI system clock, mmtimer Message-ID: <20040916181708.GB5052@ucw.cz> References: <200409161003.39258.bjorn.helgaas@hp.com> <200409161054.51467.bjorn.helgaas@hp.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <200409161054.51467.bjorn.helgaas@hp.com> User-Agent: Mutt/1.4.1i Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1997 Lines: 46 On Thu, Sep 16, 2004 at 10:54:51AM -0600, Bjorn Helgaas wrote: > On Thursday 16 September 2004 10:32 am, Christoph Lameter wrote: > > On Thu, 16 Sep 2004, Bjorn Helgaas wrote: > > > Christoph Lameter wrote: > > > > The timer hardware was designed around the multimedia timer specification by Intel > > > > but to my knowledge only SGI has implemented that standard. The driver was written > > > > by Jesse Barnes. > > > > > > As far as I can see, drivers/char/hpet.c talks to the same hardware. > > > HP sx1000 machines (and probably others) also implement the HPET. > > > > The Intel Multimedia Standard is a earlier and different timer spec. > > I have a spec that's labelled "IA-PC Multimedia Timers", preliminary > draft of June 2000, revision 0.97, which looks like the one mentioned > in your patch. > > I also have something labelled "IA-PC HPET (High Precision Event > Timers) Specification", draft of February 2002, revision 0.98, > which is what drivers/char/hpet.c supports. > > I admit I haven't compared them in great detail, but they certainly > *look* like they're close enough that the same driver could support > both, and the 0.98 revision history only mentions fairly cosmetic > changes (like the name :)). Indeed, I coded the x86-64 HPET support using the 0.97 spec, and then only did a few minor fixups when I got the 0.98 spec. > Is there something specific that drivers/char/hpet.c expects that > your hardware doesn't implement? > - > 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/ -- Vojtech Pavlik SuSE Labs, SuSE CR - 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/