From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-2.5 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_PASS,USER_AGENT_MUTT autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id B54FEC10F06 for ; Wed, 3 Apr 2019 15:57:00 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 812EC206DF for ; Wed, 3 Apr 2019 15:57:00 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726671AbfDCP47 (ORCPT ); Wed, 3 Apr 2019 11:56:59 -0400 Received: from relay7-d.mail.gandi.net ([217.70.183.200]:35375 "EHLO relay7-d.mail.gandi.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725959AbfDCP46 (ORCPT ); Wed, 3 Apr 2019 11:56:58 -0400 X-Originating-IP: 109.213.83.19 Received: from localhost (alyon-652-1-60-19.w109-213.abo.wanadoo.fr [109.213.83.19]) (Authenticated sender: alexandre.belloni@bootlin.com) by relay7-d.mail.gandi.net (Postfix) with ESMTPSA id B3AEB20012; Wed, 3 Apr 2019 15:56:55 +0000 (UTC) Date: Wed, 3 Apr 2019 17:56:54 +0200 From: Alexandre Belloni To: Flavio Suligoi Cc: Alessandro Zummo , Rob Herring , Mark Rutland , "linux-rtc@vger.kernel.org" , "devicetree@vger.kernel.org" , "linux-kernel@vger.kernel.org" Subject: Re: [PATCH 2/2] rtc: pcf2127: add battery-low INTn generation Message-ID: <20190403155654.GR22216@piout.net> References: <1554303165-24813-1-git-send-email-f.suligoi@asem.it> <1554303165-24813-2-git-send-email-f.suligoi@asem.it> <20190403150824.GO22216@piout.net> <452a4cf1410a41c8b6f767ac6258482e@asem.it> <20190403153143.GQ22216@piout.net> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.11.3 (2019-02-01) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 03/04/2019 15:49:03+0000, Flavio Suligoi wrote: > > Then, you should probably not enable BLIE because this will cause issues > > with the alarm functionnality.. It is certainly enough to use > > RTC_VL_READ periodically. > > We use the nINT signaling solution because of this pin, in addition > to be used by the CPU, can be also connected to an external connector, > available for the final user. > Anyway, even if the BLIE is set, the sw low voltage alarm works, > with the message (displayed about every 12 minutes): > I agree the DT property makes sense when the nINT pin is not connected to the CPU. But if it is, then you have an issue that nINT will be pulled low until the user changes the battery, meaning that you will not get any alarm interrupt anymore, possibly leading to a system that is not waking up anymore. > rtc-pcf2127-i2c 2-0051: low voltage detected, check/replace RTC battery. > You get that message every 11minutes because you are using ntp and systohc (which I would discourage you to use as it is inaccurate). > What kind of issues did you find with BLIE enabled? > > Flavio > -- Alexandre Belloni, Bootlin Embedded Linux and Kernel engineering https://bootlin.com