From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757709Ab3ENSAe (ORCPT ); Tue, 14 May 2013 14:00:34 -0400 Received: from smtp02.citrix.com ([66.165.176.63]:8369 "EHLO SMTP02.CITRIX.COM" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753517Ab3ENSAd (ORCPT ); Tue, 14 May 2013 14:00:33 -0400 X-IronPort-AV: E=Sophos;i="4.87,671,1363132800"; d="scan'208";a="23995089" Message-ID: <51927BBF.5010404@citrix.com> Date: Tue, 14 May 2013 19:00:31 +0100 From: David Vrabel User-Agent: Mozilla/5.0 (X11; U; Linux x86_64; en-US; rv:1.9.1.16) Gecko/20120428 Iceowl/1.0b1 Icedove/3.0.11 MIME-Version: 1.0 To: John Stultz CC: "xen-devel@lists.xen.org" , Konrad Rzeszutek Wilk , Thomas Gleixner , "linux-kernel@vger.kernel.org" Subject: Re: [PATCH 3/3] x86/xen: sync the CMOS RTC as well as the Xen wallclock References: <1368467768-2316-1-git-send-email-david.vrabel@citrix.com> <1368467768-2316-4-git-send-email-david.vrabel@citrix.com> <51927339.5070402@linaro.org> In-Reply-To: <51927339.5070402@linaro.org> Content-Type: text/plain; charset="ISO-8859-1" Content-Transfer-Encoding: 7bit X-Originating-IP: [10.80.2.76] Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 14/05/13 18:24, John Stultz wrote: > On 05/13/2013 10:56 AM, David Vrabel wrote: >> From: David Vrabel >> >> If NTP is used in dom0 and it is synchronized to its clock source, >> then the kernel will periodically synchronize the Xen wallclock with >> the system time. Updates to the Xen wallclock do not persist across >> reboots, so also synchronize the CMOS RTC (as on bare metal). >> >> Signed-off-by: David Vrabel >> --- >> arch/x86/xen/time.c | 11 ++++++++++- >> 1 files changed, 10 insertions(+), 1 deletions(-) >> >> diff --git a/arch/x86/xen/time.c b/arch/x86/xen/time.c >> index a1947ac..4656165 100644 >> --- a/arch/x86/xen/time.c >> +++ b/arch/x86/xen/time.c >> @@ -14,6 +14,7 @@ >> #include >> #include >> #include >> +#include >> >> #include >> #include >> @@ -199,17 +200,25 @@ static void xen_get_wallclock(struct timespec *now) >> static int xen_set_wallclock(const struct timespec *now) >> { >> struct xen_platform_op op; >> + int ret; >> >> /* do nothing for domU */ >> if (!xen_initial_domain()) >> return -1; >> >> + /* Set the Xen wallclock. */ >> op.cmd = XENPF_settime; >> op.u.settime.secs = now->tv_sec; >> op.u.settime.nsecs = now->tv_nsec; >> op.u.settime.system_time = xen_clocksource_read(); >> >> - return HYPERVISOR_dom0_op(&op); >> + ret = HYPERVISOR_dom0_op(&op); >> + if (ret) >> + return ret; >> + >> + /* Set the hardware RTC. */ >> + return mach_set_rtc_mmss(now); > > Sorry, just noticed one more thing while applying this. Do all Xen > systems run on hardware that has the conventional CMOS clock? > > What happens if the bare-metal needs to use efi_set_rtc() or > vrtc_set_mmss() ? Ug. I hadn't considered that. I'll have think some more on this. David