Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751168AbdGMHcK (ORCPT ); Thu, 13 Jul 2017 03:32:10 -0400 Received: from bombadil.infradead.org ([65.50.211.133]:37233 "EHLO bombadil.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750846AbdGMHcI (ORCPT ); Thu, 13 Jul 2017 03:32:08 -0400 Date: Thu, 13 Jul 2017 09:32:00 +0200 From: Peter Zijlstra To: Derek Basehore Cc: linux-kernel@vger.kernel.org, Thomas Gleixner , Ingo Molnar , Rajneesh Bhardwaj , x86@kernel.org, platform-driver-x86@vger.kernel.org, "Rafael J . Wysocki" , Len Brown , linux-pm@vger.kernel.org Subject: Re: [PATCH v5 2/5] tick: Add freeze timer events Message-ID: <20170713073200.uh3oxqowei6vxvwy@hirez.programming.kicks-ass.net> References: <20170708000303.21863-1-dbasehore@chromium.org> <20170708000303.21863-2-dbasehore@chromium.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20170708000303.21863-2-dbasehore@chromium.org> User-Agent: NeoMutt/20170609 (1.8.3) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 753 Lines: 17 On Fri, Jul 07, 2017 at 05:03:00PM -0700, Derek Basehore wrote: > Adds a new feature to tick to schedule wakeups on a CPU during freeze. > This won't fully wake up the system (devices are not resumed), but > allow simple platform functionality to be run during freeze with > little power impact. > > This implementation allows an idle driver to setup a timer event with > the clock event device when entering freeze by calling > tick_set_freeze_event. Only one caller should exist for the function. > > tick_freeze_event_expired is used to check if the timer went off when > the CPU wakes. > > The event is cleared by tick_clear_freeze_event. Why? What's wrong with using the RTC stuff? RTC should be able to wake suspended systems, see RTCWAKE(8).