From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754588AbaCLOhV (ORCPT ); Wed, 12 Mar 2014 10:37:21 -0400 Received: from mail-ob0-f171.google.com ([209.85.214.171]:39477 "EHLO mail-ob0-f171.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752673AbaCLOhR convert rfc822-to-8bit (ORCPT ); Wed, 12 Mar 2014 10:37:17 -0400 MIME-Version: 1.0 In-Reply-To: <20140307201039.GB27645@amd.pavel.ucw.cz> References: <1392875640-29230-1-git-send-email-jenny.tc@intel.com> <1392875640-29230-3-git-send-email-jenny.tc@intel.com> <20140228100114.GA13189@amd.pavel.ucw.cz> <20140307201039.GB27645@amd.pavel.ucw.cz> Date: Wed, 12 Mar 2014 15:37:17 +0100 Message-ID: Subject: Re: [PATCH 2/4] power_supply: Introduce generic psy charging driver From: Linus Walleij To: Pavel Machek Cc: Jenny TC , "linux-kernel@vger.kernel.org" , Dmitry Eremin-Solenikov , Anton Vorontsov , Anton Vorontsov , Kim Milo , Lee Jones , Jingoo Han , Chanwoo Choi , Sachin Kamat , Lars-Peter Clausen , =?ISO-8859-1?Q?Pali_Roh=E1r?= , Rhyland Klein , "Rafael J. Wysocki" , David Woodhouse , Tony Lindgren , Russell King , Sebastian Reichel , Aaro Koskinen , Pallala Ramakrishna , =?windows-1251?B?yOLg6evuIMTo7Ojy8O7i?= , Linux-OMAP Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 8BIT Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, Mar 7, 2014 at 9:10 PM, Pavel Machek wrote: > On Fri 2014-03-07 11:04:59, Linus Walleij wrote: >> On Fri, Feb 28, 2014 at 6:01 PM, Pavel Machek wrote: >> > On Thu 2014-02-27 21:08:01, Linus Walleij wrote: >> >> On Thu, Feb 20, 2014 at 6:53 AM, Jenny TC wrote: >> >> >> >> > +++ b/include/linux/power/power_supply_charger.h >> >> >> >> > +#define MAX_CUR_VOLT_SAMPLES 3 >> >> > +#define DEF_CUR_VOLT_SAMPLE_JIFF (30*HZ) >> >> >> >> Why are things defined in Jiffies like this insead of seconds, milliseconds >> >> etc? This will vary with the current operating frequency of the system, >> >> why should physical measurements do that? >> > >> > It is actually ok. The define is relative to jiffies, and that's what >> > interface expects. >> >> So consider the option that the interface is wrong. >> >> Stating something like a sample period in system-specific jiffies >> instead of period time T is just weird. What control systems >> guy would understand this? > > 30*HZ means 30 seconds in the kernel... what is hard to understand > about it? Well I might be picky, but since it is a charging algorithm dealing with ampères, volts, constant-current/constant-voltage, watchdogs and timeouts, all stated in SI units, it would be nice if all such constants were specified in simple units instead of kernel-specific terms. One reason is that this kind of code actually needs review from non-programmers, people like chemists and physicists. I know it may be far fetched so no strong preference for sure. Yours, Linus Walleij From mboxrd@z Thu Jan 1 00:00:00 1970 From: Linus Walleij Subject: Re: [PATCH 2/4] power_supply: Introduce generic psy charging driver Date: Wed, 12 Mar 2014 15:37:17 +0100 Message-ID: References: <1392875640-29230-1-git-send-email-jenny.tc@intel.com> <1392875640-29230-3-git-send-email-jenny.tc@intel.com> <20140228100114.GA13189@amd.pavel.ucw.cz> <20140307201039.GB27645@amd.pavel.ucw.cz> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: QUOTED-PRINTABLE Return-path: Received: from mail-oa0-f46.google.com ([209.85.219.46]:49428 "EHLO mail-oa0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753900AbaCLOhR convert rfc822-to-8bit (ORCPT ); Wed, 12 Mar 2014 10:37:17 -0400 Received: by mail-oa0-f46.google.com with SMTP id i7so10213330oag.19 for ; Wed, 12 Mar 2014 07:37:17 -0700 (PDT) In-Reply-To: <20140307201039.GB27645@amd.pavel.ucw.cz> Sender: linux-omap-owner@vger.kernel.org List-Id: linux-omap@vger.kernel.org To: Pavel Machek Cc: Jenny TC , "linux-kernel@vger.kernel.org" , Dmitry Eremin-Solenikov , Anton Vorontsov , Anton Vorontsov , Kim Milo , Lee Jones , Jingoo Han , Chanwoo Choi , Sachin Kamat , Lars-Peter Clausen , =?ISO-8859-1?Q?Pali_Roh=E1r?= , Rhyland Klein , "Rafael J. Wysocki" , David Woodhouse , Tony Lindgren , Russell King , Sebastian Reichel , Aaro Koskinen , Pallala Ramakrishna , =?windows-1251?B?yOLg6evuIMTo7Ojy8O7i?= Lin On Fri, Mar 7, 2014 at 9:10 PM, Pavel Machek wrote: > On Fri 2014-03-07 11:04:59, Linus Walleij wrote: >> On Fri, Feb 28, 2014 at 6:01 PM, Pavel Machek wrote: >> > On Thu 2014-02-27 21:08:01, Linus Walleij wrote: >> >> On Thu, Feb 20, 2014 at 6:53 AM, Jenny TC wr= ote: >> >> >> >> > +++ b/include/linux/power/power_supply_charger.h >> >> >> >> > +#define MAX_CUR_VOLT_SAMPLES 3 >> >> > +#define DEF_CUR_VOLT_SAMPLE_JIFF (30*HZ) >> >> >> >> Why are things defined in Jiffies like this insead of seconds, mi= lliseconds >> >> etc? This will vary with the current operating frequency of the s= ystem, >> >> why should physical measurements do that? >> > >> > It is actually ok. The define is relative to jiffies, and that's w= hat >> > interface expects. >> >> So consider the option that the interface is wrong. >> >> Stating something like a sample period in system-specific jiffies >> instead of period time T is just weird. What control systems >> guy would understand this? > > 30*HZ means 30 seconds in the kernel... what is hard to understand > about it? Well I might be picky, but since it is a charging algorithm dealing wit= h amp=E8res, volts, constant-current/constant-voltage, watchdogs and timeouts, all stated in SI units, it would be nice if all such constant= s were specified in simple units instead of kernel-specific terms. One reason is that this kind of code actually needs review from non-programmers, people like chemists and physicists. I know it may be far fetched so no strong preference for sure. Yours, Linus Walleij -- To unsubscribe from this list: send the line "unsubscribe linux-omap" i= n the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html