From mboxrd@z Thu Jan 1 00:00:00 1970 From: Matthew Garrett Subject: Re: [linux-pm] [PATCH 3/6] [-mm]: ACPI: duplicate ACPI sleep "alarm" attribute in sysfs Date: Mon, 8 Jan 2007 10:10:26 +0000 Message-ID: <20070108101026.GA14485@srcf.ucam.org> References: <1168083318.5619.37.camel@localhost.localdomain> <200701061442.22340.david-b@pacbell.net> <20070107055757.GB24853@srcf.ucam.org> <200701071831.18186.david-b@pacbell.net> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Received: from cavan.codon.org.uk ([217.147.92.49]:34623 "EHLO vavatch.codon.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1161205AbXAHKKk (ORCPT ); Mon, 8 Jan 2007 05:10:40 -0500 Content-Disposition: inline In-Reply-To: <200701071831.18186.david-b@pacbell.net> Sender: linux-acpi-owner@vger.kernel.org List-Id: linux-acpi@vger.kernel.org To: David Brownell Cc: lenb@kernel.org, "linux-acpi@vger" , linux-pm@lists.osdl.org, Zhang Rui On Sun, Jan 07, 2007 at 06:31:17PM -0800, David Brownell wrote: > On Saturday 06 January 2007 9:57 pm, Matthew Garrett wrote: > > Especially since /proc/acpi/alarm is just banging on the RTC registers > > - the only ACPI thing about it is that the FADT can expose whether or > > not the extended registers exist, and then making sure that the GPE is > > enabled. > > The FADT also exposes whether the RTC can wake from S4. You may have > noticed that my rtc-cmos patch #3 exported the relevant FADT info > to the RTC device using platform_data, but the S4 wake capability flag > isn't useful for anything on today's Linux. Isn't useful in what way? It'd be helpful for userspace to know that now that we're actually using S4 for swsusp, but I understand that it might not fit into the current API terribly well. > Not speaking as an ACPI expert, I do see the ACPI spec says (right > under fig 4-11 in my version) that RTC events don't require GPEs. Hmm. My interpretation of that section had been that RTC_EN and RTC_STS were optional, and that a GPE would be required if they weren't implemented. On re-reading it, I think you're right. -- Matthew Garrett | mjg59@srcf.ucam.org