From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1764064AbYFKQhv (ORCPT ); Wed, 11 Jun 2008 12:37:51 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751045AbYFKQhn (ORCPT ); Wed, 11 Jun 2008 12:37:43 -0400 Received: from fg-out-1718.google.com ([72.14.220.156]:7272 "EHLO fg-out-1718.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750733AbYFKQhm (ORCPT ); Wed, 11 Jun 2008 12:37:42 -0400 DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=message-id:date:from:user-agent:mime-version:to:cc:subject :references:in-reply-to:content-type:content-transfer-encoding; b=PjtkWfG7hvY0H8b3ema1Q0nsdjqvavIu+gqV854TzVSW/4XSk+txu7O6f7cV3kCGKY 6ocRoGPbiQjTZxgY9eQLYK+Cz5gnvSzn79FSXnWk5tzW0cZhXgyI/Q05s9AP3RjlkyLH GsX9cvOPwnd8FYeqdvKxy1vVmmMkWZ4paV+Ho= Message-ID: <484FFF4E.9020007@gmail.com> Date: Wed, 11 Jun 2008 19:37:34 +0300 From: Maxim Levitsky User-Agent: Thunderbird 2.0.0.14 (X11/20080505) MIME-Version: 1.0 To: David Brownell CC: Andrew Morton , lkml , Thomas Gleixner Subject: Re: [patch 2.6.26-rc5] make HPET_RTC_IRQ track HPET_EMULATE_RTC References: <200806052241.44713.david-b@pacbell.net> <200806061644.23449.maximlevitsky@gmail.com> <200806101431.21402.david-b@pacbell.net> In-Reply-To: <200806101431.21402.david-b@pacbell.net> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org David Brownell wrote: > On Friday 06 June 2008, Maxim Levitsky wrote: > >> Remember long ago I had a discussion with you about HPET that >> steals RTC irq in 'legacy replacement' mode, and rtc driver thus >> implements rtc on 'top' of hpet. >> >> New rtc-cmos driver doesn't do this emulation, thus it isn't compatible >> with hpet driver. > > That was fixed in 9d8af78b07976d4d84e0df491abd4e9db848d0ad (February) > by Bernhard Walle ... if you look at the bug report > associated with this patch, you'll see that rtc-cmos was working OK > with HPET, it's just the legacy RTC driver which got confused after > the recent updates to clock handling. > > >> But there is a solution, I didn't agree with firstly, but then I did, and >> I do agree now, and that to put hpet in normal mode. >> >> What happened with patches that put hpet in normal independent mode? > > The story from either Ingo or Thomas (I forget who) was that this is > another case where we have to cope with BIOS braindamage. Not enough > BIOS vendors expose the relevant IRQ routing that Linux could default > to using HPET in what I'd call "sane" mode. > > Now, that still kind of implies there could be an option to use sane > HPET IRQ configuration (doesn't hijack RTC and other IRQs, and there > could be a per-CPU HPET) on at least the systems where that IRQ routing > is available. Over time I'd hope that systems like that could become > the common case. But ... someone else would have to do that work. :) > > - Dave Thanks a lot, next time I compile the kernel, I will enable hpet Best regards, Maxim Levitsky PS: This is a question to ubuntu devs, I need to ask them, when they will switch to new rtc driver.... Old driver has some bugs, including no support for suspend/resume, some troubles with alarm (it sets the alarm when writing to /proc/acpi/alarm, but it can be cleared by even just reading the time. New driver correctly sets the alarm at actual suspend time) Even hpet emulation has some bugs, I even wrote some patches to fix this and add suspend/resume, but I guess that newer driver is way better, so no need to fix old one.