Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755639AbcC2Bwp (ORCPT ); Mon, 28 Mar 2016 21:52:45 -0400 Received: from mailgw02.mediatek.com ([210.61.82.184]:25058 "EHLO mailgw02.mediatek.com" rhost-flags-OK-FAIL-OK-FAIL) by vger.kernel.org with ESMTP id S1754307AbcC2Bwj (ORCPT ); Mon, 28 Mar 2016 21:52:39 -0400 Message-ID: <1459216353.16645.20.camel@mtksdaap41> Subject: Re: [PATCH] sbs-battery: fix power status when battery is dry From: YH Huang To: Rhyland Klein CC: Daniel Kurtz , , "Dmitry Eremin-Solenikov" , Sebastian Reichel , "linux-kernel@vger.kernel.org" , "moderated list:ARM/Mediatek SoC support" , Matthias Brugger , David Woodhouse , "linux-arm-kernel@lists.infradead.org" Date: Tue, 29 Mar 2016 09:52:33 +0800 In-Reply-To: <56F95451.5040607@nvidia.com> References: <1458726794-48298-1-git-send-email-yh.huang@mediatek.com> <1458801832.16645.7.camel@mtksdaap41> <1459132330.16645.14.camel@mtksdaap41> <56F95451.5040607@nvidia.com> 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: 4305 Lines: 94 On Mon, 2016-03-28 at 11:57 -0400, Rhyland Klein wrote: > On 3/28/2016 6:05 AM, Daniel Kurtz wrote: > > +Rhyland Klein who original wrote this code... > > > > On Mon, Mar 28, 2016 at 10:32 AM, YH Huang wrote: > >> > >> 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. > > > The only difference I see in the patch above is that in the case where > DISCHARGING isn't set, it won't check FULL_DISCHARGE. Nothing seems to > be changed in the case where FULL_DISCHARGE & DISCHARGING are set. If battery is dry(FULLY_DISCHARGED) and is charging(No BATTERY_DISCHARGING) by AC at the same time, I think it is better to mark as POWER_SUPPLY_STATUS_CHARGING. Is this right? > > I think in the case that both flags are set, it makes sense to > prioritize the FULL_DISCHARGE, since as quote above actually starts with > "FULLY_DISCHARGED bit is set when the Smart Battery determines that it > has supplied all the charge it can." I think at the point where both > statuses are reported, the fact that it is still DISCHARGING doesn't > matter. The code as is handles this in that manner, so I don't see a > need to change it. > > -rhyland > >