From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758705Ab3BFVM2 (ORCPT ); Wed, 6 Feb 2013 16:12:28 -0500 Received: from mail.linuxfoundation.org ([140.211.169.12]:53765 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1758462Ab3BFVM1 (ORCPT ); Wed, 6 Feb 2013 16:12:27 -0500 Date: Wed, 6 Feb 2013 13:12:25 -0800 From: Andrew Morton To: Jonghwa Lee Cc: linux-kernel@vger.kernel.org, a.zummo@towertech.it, rtc-linux@googlegroups.com Subject: Re: [PATCH] rtc: core: Prevent repeated calling of alarm_irq_enable(). Message-Id: <20130206131225.83a118fe.akpm@linux-foundation.org> In-Reply-To: <1360149765-19565-1-git-send-email-jonghwa3.lee@samsung.com> References: <1360149765-19565-1-git-send-email-jonghwa3.lee@samsung.com> X-Mailer: Sylpheed 3.0.2 (GTK+ 2.20.1; x86_64-pc-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, 06 Feb 2013 20:22:45 +0900 Jonghwa Lee wrote: > This patch removes repeated execution of disabling alarm in > rtc_alarm_irq_enable() of rtc core interface. It made useless > call even all alarm had been disabled from rtc_timer_remove(). > We'd better to skip disabling alarm when timer queue is empty. > I fear that patch does more than that. > --- a/drivers/rtc/interface.c > +++ b/drivers/rtc/interface.c > @@ -428,7 +428,7 @@ int rtc_alarm_irq_enable(struct rtc_device *rtc, unsigned int enabled) > rtc_timer_remove(rtc, &rtc->aie_timer); > } > > - if (err) > + if (err || !rtc->timerqueue.next) > /* nothing */; > else if (!rtc->ops) > err = -ENODEV; This will prevent the irq from being *enabled*, as well as disabled. To match your description, we'd need to also check that enabled==0?