From mboxrd@z Thu Jan 1 00:00:00 1970 From: David Brownell Subject: Re: [linux-pm] [PATCH 3/6] [-mm]: ACPI: duplicate ACPI sleep "alarm" attribute in sysfs Date: Mon, 8 Jan 2007 12:39:08 -0800 Message-ID: <200701081239.08687.david-b@pacbell.net> References: <1168083318.5619.37.camel@localhost.localdomain> <200701071831.18186.david-b@pacbell.net> <20070108101026.GA14485@srcf.ucam.org> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <20070108101026.GA14485@srcf.ucam.org> Content-Disposition: inline Sender: linux-acpi-owner@vger.kernel.org To: Matthew Garrett Cc: lenb@kernel.org, "linux-acpi@vger" , linux-pm@lists.osdl.org, Zhang Rui List-Id: linux-pm@vger.kernel.org > > 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. In that current API there's no way to tell anything at all about the target system state inside a driver's suspend() method. So if there were some characteristic of S4 (or S3 etc) that mattered to the driver (it should test for the attribute, not S4/etc since S4 is ACPI-specific) the driver couldn't do anything about it ... so as I said, not useful. - Dave