From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S965621AbXC1SEV (ORCPT ); Wed, 28 Mar 2007 14:04:21 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S965626AbXC1SEV (ORCPT ); Wed, 28 Mar 2007 14:04:21 -0400 Received: from nf-out-0910.google.com ([64.233.182.187]:36716 "EHLO nf-out-0910.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S965620AbXC1SET (ORCPT ); Wed, 28 Mar 2007 14:04:19 -0400 Date: Wed, 28 Mar 2007 20:04:57 +0200 From: "Michael S. Tsirkin" To: Maxim Cc: Thomas Gleixner , Jeff Chua , Adrian Bunk , Linus Torvalds , Andrew Morton , Linux Kernel Mailing List , "Eric W. Biederman" , "Rafael J. Wysocki" , pavel@suse.cz, linux-pm@lists.osdl.org, gregkh@suse.de, linux-pci@atrey.karlin.mff.cuni.cz, Jens Axboe , Len Brown , linux-acpi@vger.kernel.org, jgarzik@pobox.com, linux-ide@vger.kernel.org, Ingo Molnar Subject: Re: [3/6] 2.6.21-rc4: known regressions Message-ID: <20070328180457.GA4253@mellanox.co.il> Reply-To: "Michael S. Tsirkin" References: <1175065468.4017.1.camel@chaos> <200703281543.47049.maximlevitsky@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <200703281543.47049.maximlevitsky@gmail.com> User-Agent: Mutt/1.5.11 Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org > Subject : first disk access after resume takes several minutes > ('date' does not advance after resume from RAM, CONFIG_NO_HZ=n) > References : http://lkml.org/lkml/2007/3/8/117 > http://lkml.org/lkml/2007/3/25/20 > Submitter : Michael S. Tsirkin ... > Subject : after resume: X hangs after drawing a couple of windows > References : http://lkml.org/lkml/2007/3/8/117 > Submitter : Michael S. Tsirkin > Status : unknown ... > > > > From: Jeff Chua > > > > > It's related. I tested without CONFIG_HPET_TIMER, and now my X60 can > > > > > suspend and resume from RAM (s2ram). Even better, it works > > > > > with/without CONFIG_NO_HZ. > > Quoting Maxim : > > Hi, > I almost sure Iknow why this happens, > The problem is that both hpet clock source > and hpet clockevents doesn't have a suspend/resume function > On resume we should enable the main counter _and_ enable > legacy replacement mode, On my system main counter in > enabled, by I think by bios, but legacy replacement mode is > not, so if a system doesn't use lapic as a tick source, but > use hpet+broadcast, it will hang for sure on resume, and i > tested it > > The patch below is a temporally fix, until > clock-events and clocksources will get proper suspend/resume > hooks: > > Regards, > Maxim Levitsky Bingo! The patch below fixes the two problems (listed above) with resume from RAM that I have observed on my T60 with 2.6.21-rc5: with this patch applied, and with CONFIG_NO_HZ unset, date advances correctly, X functions properly and there is no delay on first disk access. Thanks very much. --- > Add suspend/resume for HPET > Signed-off-by: Maxim Levitsky Maxim, do you plan to send this upstream? Acked-by: Michael S. Tsirkin --- diff --git a/arch/i386/kernel/hpet.c b/arch/i386/kernel/hpet.c index 0fd9fba..a1ec79e 100644 --- a/arch/i386/kernel/hpet.c +++ b/arch/i386/kernel/hpet.c @@ -152,6 +152,16 @@ static void hpet_set_mode(enum clock_event_mode mode, unsigned long cfg, cmp, now; uint64_t delta; + + if ( mode != CLOCK_EVT_MODE_UNUSED && mode != CLOCK_EVT_MODE_SHUTDOWN) + { + unsigned long cfg = hpet_readl(HPET_CFG); + cfg |= HPET_CFG_ENABLE | HPET_CFG_LEGACY; + hpet_writel(cfg, HPET_CFG); + + } + + switch(mode) { case CLOCK_EVT_MODE_PERIODIC: delta = ((uint64_t)(NSEC_PER_SEC/HZ)) * hpet_clockevent.mult; -- MST