Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752485AbaKJLWs (ORCPT ); Mon, 10 Nov 2014 06:22:48 -0500 Received: from mga01.intel.com ([192.55.52.88]:45531 "EHLO mga01.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750933AbaKJLWq (ORCPT ); Mon, 10 Nov 2014 06:22:46 -0500 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.07,352,1413270000"; d="scan'208";a="629474462" Message-ID: <1415618533.14686.239.camel@mfleming-mobl1.ger.corp.intel.com> Subject: Re: [PATCH] rtc: Disable EFI rtc for x86 From: Matt Fleming To: Borislav Petkov CC: Pali =?ISO-8859-1?Q?Roh=E1r?= , Mark Salter , Alessandro Zummo , , , , Dave Young , "H. Peter Anvin" , Matthew Garrett Date: Mon, 10 Nov 2014 11:22:13 +0000 In-Reply-To: <20141109182231.GA29337@pd.tnic> References: <1412339576-17972-1-git-send-email-matt@console-pimps.org> <1412348517.5410.13.camel@deneb.redhat.com> <201411091837.47354@pali> <20141109182231.GA29337@pd.tnic> Organization: Intel Corporation (UK) Ltd. - Registered No. 1134945 - Pipers Way, Swindon SN3 1RJ Content-Type: text/plain; charset="UTF-8" X-Mailer: Evolution 3.10.4 (3.10.4-4.fc20) MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Originating-IP: [163.33.239.180] Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Sun, 2014-11-09 at 19:22 +0100, Borislav Petkov wrote: > On Sun, Nov 09, 2014 at 06:37:46PM +0100, Pali Rohár wrote: > > this patch totally disabled efi rfc driver on x86 machines at > > compile time. But on some x86 machines it working without crash > > and reading from file /sys/class/rtc/rtc*/since_epoch returns > > correct information. So why to disable compiling driver on > > machines where driver working? > > Sounds like we need an efi=rtc_enable knob for people who what to use > it... I'm not so sure. By and large, the EFI runtime Time services just don't work very well on x86. Just because they work sometimes, doesn't actually mean it's a good idea to use them. The one scenario where the time services are useful is early on during boot when we want to get the timezone information. I have vague recollections of someone working on that. -- 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/