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=-3.9 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_PASS,URIBL_BLOCKED autolearn=ham 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 71BF5C43382 for ; Wed, 26 Sep 2018 08:00:48 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 28CB32082C for ; Wed, 26 Sep 2018 08:00:48 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=linaro.org header.i=@linaro.org header.b="isOMcTQ5" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 28CB32082C Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=linaro.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727418AbeIZOM0 (ORCPT ); Wed, 26 Sep 2018 10:12:26 -0400 Received: from mail-it1-f194.google.com ([209.85.166.194]:50825 "EHLO mail-it1-f194.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726951AbeIZOMZ (ORCPT ); Wed, 26 Sep 2018 10:12:25 -0400 Received: by mail-it1-f194.google.com with SMTP id j81-v6so1775908ite.0 for ; Wed, 26 Sep 2018 01:00:45 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linaro.org; s=google; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=BqACATKMnsXu5MClIMk0CeKzY8X21wBn/ky+o7hh2wI=; b=isOMcTQ5X1Hux37Oqpw7cMNsZBQrVqVuQHovmpDeWZBKTBEOo45XRUI/N4FalbohDR /+6oM+35/9Z2NYs7WaBqMPF65ryp2f8MQec/Ng5CtTDpC+l0xFSqlspQ5vYXAEMg+umd Bc6UGJV1do19K/h/CsV9SixeSgr6w1Ma7xHTo= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=BqACATKMnsXu5MClIMk0CeKzY8X21wBn/ky+o7hh2wI=; b=CE0Grmzih1syZ00xqBitYvDz6vOYsW4UsGtZn1mYVL1oD0tbHWhmi0eZ0Mmn+52jbL vug5TzrCUbnyDTI8idgUsyroZ4aP848hF8dPtJqrZ1YA5PkgglnpXciVqECPG5ob1DMs jA89+WQXt1yuXFIrNhHo3ZiRFH5zPZcl+WxkOtBGdrBZfp+F0H6mbFGwHpLXZJ9erVNO oWC23eQlkpF1O78WeG4hZIWsM/JfW+zGrYqaky/Xv1VAgGGSl3jspDdhMf0PP4bmJdDq 8h9kZkqRHbPWGYun5NxzCoSbAYLjc6/uqaUf88vwXYTTzchGAXJwFcCvOB0E3sg0UK7b d3Hw== X-Gm-Message-State: ABuFfohZcKb4iMc58ZYHIrclg7lO7dkQOofX7MUlQykehnBpPBSEw/UR nrN3iyW69OrfZi8SvGai5kit0pCPdGICatEWfwETYQ== X-Google-Smtp-Source: ACcGV61/dSlwHMTpGHkIKsJ10jY4MyLb4+rxKW9SadV4OYcGjKwPLQOc7SzFLqws3uxTUNsJRqgv+f/GPjCWC/aVYP8= X-Received: by 2002:a02:6c45:: with SMTP id w66-v6mr4535661jab.87.1537948845418; Wed, 26 Sep 2018 01:00:45 -0700 (PDT) MIME-Version: 1.0 References: <358665e3f4f9ec105dc2f8a2dc6dd98dbe761fae.1537930252.git.baolin.wang@linaro.org> In-Reply-To: <358665e3f4f9ec105dc2f8a2dc6dd98dbe761fae.1537930252.git.baolin.wang@linaro.org> From: Linus Walleij Date: Wed, 26 Sep 2018 10:00:33 +0200 Message-ID: Subject: Re: [PATCH v2 1/4] power: supply: core: Introduce one property to present the battery internal resistance To: Baolin Wang Cc: Sebastian Reichel , Rob Herring , Mark Rutland , Linux PM list , "open list:OPEN FIRMWARE AND FLATTENED DEVICE TREE BINDINGS" , "linux-kernel@vger.kernel.org" , yuanjiang.yu@unisoc.com, Mark Brown , Craig Tatlor Content-Type: text/plain; charset="UTF-8" Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Sep 26, 2018 at 4:59 AM Baolin Wang wrote: > Introduce one property to present the battery internal resistance for battery > information. > > Signed-off-by: Baolin Wang > --- > Changes from v1: > - New patch in v2. I'm a bit confused by the physics in this patch. The internal resistance of a battery is not a constant in its life cycle, this varies over the age of the battery, and the reason I thing is chemical residuals accumulating on the anode and cathode inside the battery and the energy storage medium aging. (Plus/minus my ignorance about how batteries actually work.) AFAIK the fact that the internal resistance varies is of high importance for people developing algorithms of battery capacity and longevity. Such that some (hardware) capacity monitors go to great lengths to measure with high precision the current internal resistance of the battery for their algorithms. Sorry for making things more complex, but should it be named "factory-internal-resistance-micro-ohms" or "typical-internal-resistance-micro-ohms"? Yours, Linus Walleij