From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754725AbbAVVIW (ORCPT ); Thu, 22 Jan 2015 16:08:22 -0500 Received: from www.linutronix.de ([62.245.132.108]:33511 "EHLO Galois.linutronix.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754686AbbAVVIS (ORCPT ); Thu, 22 Jan 2015 16:08:18 -0500 Date: Thu, 22 Jan 2015 22:07:57 +0100 (CET) From: Thomas Gleixner To: Xunlei Pang cc: linux-kernel@vger.kernel.org, rtc-linux@googlegroups.com, Alessandro Zummo , John Stultz , Arnd Bergmann Subject: Re: [PATCH v2 3/3] time: clocksource: Add a comment to CLOCK_SOURCE_SUSPEND_NONSTOP In-Reply-To: <1421928077-4698-3-git-send-email-pang.xunlei@linaro.org> Message-ID: References: <1421928077-4698-1-git-send-email-pang.xunlei@linaro.org> <1421928077-4698-3-git-send-email-pang.xunlei@linaro.org> User-Agent: Alpine 2.11 (DEB 23 2013-08-11) MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII X-Linutronix-Spam-Score: -1.0 X-Linutronix-Spam-Level: - X-Linutronix-Spam-Status: No , -1.0 points, 5.0 required, ALL_TRUSTED=-1,SHORTCIRCUIT=-0.0001 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, 22 Jan 2015, Xunlei Pang wrote: > When doing timekeeping_resume(), if the nonstop clocksource > wraps back, "cycle_delta" will miss the wrap time. > > It's hard to determine the right CLOCKSOURCE_MASK(xxx) or > something to add code for inspecting such behavior, and we > don't have many existent nonstop clocksources, so just add > a comment to indicate that if have this flag set, people > are aware that this nonstop clocksource won't wrap back > during system suspend/resume. -ENOPARSE What has the CLOCKSOURCE_MASK() to do with this and why is the fact relevant, that we only have a few suspend_nonstop clock sources? > + > +/* > + * When setting this flag, you're also supposed to mean that it doesn't > + * wrap back during system suspend/resume. See timekeeping_resume(). -ENOPARSE I guess what you want to say here is: /* * clocksource continues to run during suspend and is guaranteed not to * wrap around during long suspend periods. */ > + */ > #define CLOCK_SOURCE_SUSPEND_NONSTOP 0x80 Thanks, tglx