From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755830AbcIFJrn (ORCPT ); Tue, 6 Sep 2016 05:47:43 -0400 Received: from mail-oi0-f66.google.com ([209.85.218.66]:35089 "EHLO mail-oi0-f66.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753534AbcIFJrl (ORCPT ); Tue, 6 Sep 2016 05:47:41 -0400 MIME-Version: 1.0 In-Reply-To: <20160905222656.ziowskma2gizsjtj@piout.net> References: <20160831225900.20122-1-gabriele.mzt@gmail.com> <20160905222656.ziowskma2gizsjtj@piout.net> From: Gabriele Mazzotta Date: Tue, 6 Sep 2016 11:47:39 +0200 Message-ID: Subject: Re: [PATCH v2 1/2] rtc-cmos: Ensure no expired alarm is left enabled after resume To: Alexandre Belloni Cc: Alessandro Zummo , rtc-linux@googlegroups.com, "linux-kernel@vger.kernel.org" , matthew.garrett@nebula.com Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 2016-09-06 0:26 GMT+02:00 Alexandre Belloni : > Hi > > On 01/09/2016 at 00:58:59 +0200, Gabriele Mazzotta wrote : >> static int cmos_resume(struct device *dev) >> { >> struct cmos_rtc *cmos = dev_get_drvdata(dev); >> unsigned char tmp; >> + bool is_wkalrm_expired; >> >> if (cmos->enabled_wake) { >> if (cmos->wake_off) >> @@ -913,6 +935,8 @@ static int cmos_resume(struct device *dev) >> cmos->enabled_wake = 0; >> } >> >> + is_wkalrm_expired = cmos_is_wkalrm_expired(dev); >> + >> spin_lock_irq(&rtc_lock); >> tmp = cmos->suspend_ctrl; >> cmos->suspend_ctrl = 0; >> @@ -939,6 +963,17 @@ static int cmos_resume(struct device *dev) >> tmp &= ~RTC_AIE; >> hpet_mask_rtc_irq_bit(RTC_AIE); >> } while (mask & RTC_AIE); >> + >> + /* >> + * If RTC_AIE is set and we have an alarm set to go off in the >> + * past, then the BIOS woke the system when the alarm went off >> + * and we now have to clear it. >> + */ >> + if ((tmp & RTC_AIE) && is_wkalrm_expired) { > > Is there any issue dropping is_wkalrm_expired and calling > cmos_is_wkalrm_expired() here? That would avoid calling > cmos_is_wkalrm_expired on each wakeup. Yes, get_rtc_time() (cmos_read_time()) tries to aquire rtc_lock. > -- > Alexandre Belloni, Free Electrons > Embedded Linux and Kernel engineering > http://free-electrons.com