From mboxrd@z Thu Jan 1 00:00:00 1970 From: Bryan Henderson Subject: Re: battery drains after shutdown Date: 15 Feb 2015 23:36:02 +0000 Message-ID: <72477.bryanh@giraffe-data.com> References: <1423899504.11560.128.camel@rzhang1-mobl4> Return-path: Received: from rhino.giraffe-data.com ([174.143.232.82]:54438 "EHLO rhino.giraffe-data.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753341AbbBPAKB (ORCPT ); Sun, 15 Feb 2015 19:10:01 -0500 In-reply-to: <1423899504.11560.128.camel@rzhang1-mobl4> (rui.zhang@intel.com) Sender: linux-pm-owner@vger.kernel.org List-Id: linux-pm@vger.kernel.org To: rui.zhang@intel.com Cc: user.anti-spam@maison.homelinux.net, linux-pm@vger.kernel.org I don't know much about power states in general, and I can't think of any reason that any manipulation of the hardware clock would affect the power state to which the computer shuts down. This is probably more of a question for an expert on shutdown. I've heard of setting the clock disabling the wakeup, but not setting the clock enabling wakeup. I think you can determine whether this is happening, though, by looking at /proc/driver/rtc contents before and after a hwclock --systohc. I do have one comment: doing hwclock --systohc at shutdown is almost always the wrong thing to do; it is a custom that made sense 20 years ago, but not today. -- Bryan Henderson San Jose, California