Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753570AbcC1CcS (ORCPT ); Sun, 27 Mar 2016 22:32:18 -0400 Received: from mailgw02.mediatek.com ([210.61.82.184]:2962 "EHLO mailgw02.mediatek.com" rhost-flags-OK-FAIL-OK-FAIL) by vger.kernel.org with ESMTP id S1753177AbcC1CcR (ORCPT ); Sun, 27 Mar 2016 22:32:17 -0400 Message-ID: <1459132330.16645.14.camel@mtksdaap41> Subject: Re: [PATCH] sbs-battery: fix power status when battery is dry From: YH Huang To: Daniel Kurtz CC: Sebastian Reichel , Dmitry Eremin-Solenikov , David Woodhouse , "Matthias Brugger" , , "linux-kernel@vger.kernel.org" , "linux-arm-kernel@lists.infradead.org" , "moderated list:ARM/Mediatek SoC support" Date: Mon, 28 Mar 2016 10:32:10 +0800 In-Reply-To: References: <1458726794-48298-1-git-send-email-yh.huang@mediatek.com> <1458801832.16645.7.camel@mtksdaap41> Content-Type: text/plain; charset="UTF-8" X-Mailer: Evolution 3.2.3-0ubuntu6 Content-Transfer-Encoding: 8bit MIME-Version: 1.0 X-MTK: N Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 3048 Lines: 64 On Fri, 2016-03-25 at 11:06 +0800, Daniel Kurtz wrote: > On Thu, Mar 24, 2016 at 2:43 PM, YH Huang wrote: > > > > Hi Daniel, > > > > On Thu, 2016-03-24 at 12:01 +0800, Daniel Kurtz wrote: > > > Hi YH, > > > > > > On Wed, Mar 23, 2016 at 5:53 PM, YH Huang wrote: > > > > When the battery is dry and BATTERY_FULL_DISCHARGED is set, > > > > we should check BATTERY_DISCHARGING to decide the power status. > > > > If BATTERY_DISCHARGING is set, the power status is not charging. > > > > Or the power status should be charging. > > > > > > > > Signed-off-by: YH Huang > > > > --- > > > > drivers/power/sbs-battery.c | 22 ++++++++++++---------- > > > > 1 file changed, 12 insertions(+), 10 deletions(-) > > > > > > > > diff --git a/drivers/power/sbs-battery.c b/drivers/power/sbs-battery.c > > > > index d6226d6..d86db0e 100644 > > > > --- a/drivers/power/sbs-battery.c > > > > +++ b/drivers/power/sbs-battery.c > > > > @@ -382,11 +382,12 @@ static int sbs_get_battery_property(struct i2c_client *client, > > > > > > > > if (ret & BATTERY_FULL_CHARGED) > > > > val->intval = POWER_SUPPLY_STATUS_FULL; > > > > - else if (ret & BATTERY_FULL_DISCHARGED) > > > > - val->intval = POWER_SUPPLY_STATUS_NOT_CHARGING; > > > > - else if (ret & BATTERY_DISCHARGING) > > > > - val->intval = POWER_SUPPLY_STATUS_DISCHARGING; > > > > - else > > > > + else if (ret & BATTERY_DISCHARGING) { > > > > + if (ret & BATTERY_FULL_DISCHARGED) > > > > + val->intval = POWER_SUPPLY_STATUS_NOT_CHARGING; > > > > + else > > > > + val->intval = POWER_SUPPLY_STATUS_DISCHARGING; > > > > + } else > > > > > > > > > I think (BATTERY_DISCHARGING && BATTERY_FULL_DISCHARGED) is still > > > POWER_SUPPLY_STATUS_DISCHARGING. > > > So, let's just report what the battery says and do: > > > > > > else if (ret & BATTERY_DISCHARGING) > > > val->intval = POWER_SUPPLY_STATUS_DISCHARGING; > > > > > So we just ignore the special situation (BATTERY_DISCHARGING && > > BATTERY_FULL_DISCHARGED). > > Isn't POWER_SUPPLY_STATUS_NOT_CHARGING a useful information? > > The battery is discharging. The fact that it is also reporting that > it is already "discharged" just seems premature. I would expect to > only see NOT_CHARGING if completely discharged *and* not discharging. I check the "Smart Battery Data Specification Revision 1.1". And there are some words about FULLY_DISCHARGED. "Discharge should be stopped soon." "This status bit may be set prior to the ‘TERMINATE_DISCHARGE_ALARM’ as an early or first level warning of end of battery charge." It looks like the FULLY_DISCHARGED status is used to announce the warning of battery charge and it is still discharging if there is no one takes care of it.