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=-2.2 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_SANE_1 autolearn=no 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 1F420C433E1 for ; Tue, 16 Jun 2020 10:52:38 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 0616D20776 for ; Tue, 16 Jun 2020 10:52:38 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728632AbgFPKwg (ORCPT ); Tue, 16 Jun 2020 06:52:36 -0400 Received: from jabberwock.ucw.cz ([46.255.230.98]:53586 "EHLO jabberwock.ucw.cz" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728168AbgFPKwf (ORCPT ); Tue, 16 Jun 2020 06:52:35 -0400 Received: by jabberwock.ucw.cz (Postfix, from userid 1017) id 7B9DD1C0BD2; Tue, 16 Jun 2020 12:52:33 +0200 (CEST) Date: Tue, 16 Jun 2020 12:52:24 +0200 From: Pavel Machek To: "Andrew F. Davis" Cc: Krzysztof Kozlowski , Pali Roh??r , Sebastian Reichel , Krzysztof Kozlowski , linux-kernel@vger.kernel.org, linux-pm@vger.kernel.org Subject: Re: [PATCH 1/2] power: supply: bq27xxx_battery: Notify about all battery changes Message-ID: <20200616105224.GF1718@bug> References: <20200525141200.17199-1-krzk@kernel.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.23 (2014-03-12) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue 2020-05-26 21:24:39, Andrew F. Davis wrote: > On 5/25/20 10:11 AM, Krzysztof Kozlowski wrote: > > All battery related data could be important for user-space. For example > > time-to-full could be shown to user on the screen or health could be > > monitored for any issues. Instead of comparing few selected old/new > > values, just check if anything changed in the cache. > > > > > At least some value will change every time we poll the battery, are we > okay with having power_supply_changed() called every time? I believe that's very bad idea. AFAICT that would wake up userspace every 5 seconds, eating power in unexpected way, and without easy ability of opting out. IOW a regression. Pavel -- (english) http://www.livejournal.com/~pavelmachek (cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html