Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758103AbXEMRdP (ORCPT ); Sun, 13 May 2007 13:33:15 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1754239AbXEMRdD (ORCPT ); Sun, 13 May 2007 13:33:03 -0400 Received: from www.osadl.org ([213.239.205.134]:33341 "EHLO mail.tglx.de" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1751006AbXEMRdA (ORCPT ); Sun, 13 May 2007 13:33:00 -0400 Subject: Re: [patch] make pit clocksource continuous From: Thomas Gleixner Reply-To: tglx@linutronix.de To: Stas Sergeev Cc: Linux kernel In-Reply-To: <46474975.1080204@aknet.ru> References: <46464B5C.2080302@aknet.ru> <1179040612.22481.237.camel@localhost.localdomain> <4646D493.9000309@aknet.ru> <1179068094.22481.248.camel@localhost.localdomain> <46474175.7030205@aknet.ru> <1179075026.22481.273.camel@localhost.localdomain> <46474975.1080204@aknet.ru> Content-Type: text/plain Date: Sun, 13 May 2007 19:36:12 +0200 Message-Id: <1179077772.22481.279.camel@localhost.localdomain> Mime-Version: 1.0 X-Mailer: Evolution 2.6.1 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1402 Lines: 42 On Sun, 2007-05-13 at 21:23 +0400, Stas Sergeev wrote: > Hello. > > Thomas Gleixner wrote: > >> Does this mean that on even an older > >> boards (without acpi at all) the hrtimers > >> won't work? > > Not if PIT is the only clocksource available. > So you mean it can work without both the > pm_timer and hpet? Sorry for bothering you > too much, but I am trying to use the hrtimers > in my driver module, so I'd like to know all > the corner-cases. It does _NOT_ work without pm_timer or hpet for the reasons explained before. When PIT is the only clocksource in the system, i.e. no HPET and no PM_TIMER is available, then highres and dynticks are disabled. > How can I test that situation when the hrtimers > work only with PIT? Apparently disabling the > pm_timer and hpet in config doesn't help testing > it at all, since it simply refuses to work then. It is supposed to refuse to switch to highres / dyntick when you disabled pm_timer and hpet. > Should I use hrtimer_get_res() to see if the > hrtimers are available, or is there any better way? hrtimer_get_res() works, but I have no idea why you need hrtimers in your driver at all. tglx - 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/