Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757888Ab2EaMrL (ORCPT ); Thu, 31 May 2012 08:47:11 -0400 Received: from mail-pb0-f46.google.com ([209.85.160.46]:55443 "EHLO mail-pb0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756895Ab2EaMrJ convert rfc822-to-8bit (ORCPT ); Thu, 31 May 2012 08:47:09 -0400 MIME-Version: 1.0 In-Reply-To: <4FC71617.7070801@samsung.com> References: <1337919230-8296-1-git-send-email-jonghwa3.lee@samsung.com> <4FC43018.9040702@samsung.com> <4FC5F866.6030708@samsung.com> <4FC71617.7070801@samsung.com> Date: Thu, 31 May 2012 18:17:08 +0530 Message-ID: Subject: Re: [PATCH v4] regulator: MAX77686: Add Maxim 77686 regulator driver From: Yadwinder Singh Brar To: jonghwa3.lee@samsung.com Cc: linux-kernel@vger.kernel.org, Liam Girdwood , Mark Brown , Chiwoong Byun , Myungjoo Ham , Kyungmin Park Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8BIT Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 4932 Lines: 133 PLEASE On Thu, May 31, 2012 at 12:26 PM, wrote: > On 2012년 05월 30일 21:08, Yadwinder Singh Brar wrote: > >> Hi Jonghwa, >> >> On Wed, May 30, 2012 at 4:07 PM,   wrote: >>> Hi Yadwinder, >>> >>> I'm sorry for late reply. I understand the problem you pointed out, but >>> i don't agree with you all. >> >> Sorry,I think you didn't get my points. Lets forget my code and talk >> about this code now. >> >>>>>>> + >>>>>>> +       for (i = 0; i < MAX77686_REGULATORS; i++) { >>>>>>> +               if (pdata) >>>>>>> +                       init_data[pdata->regulators[i].id] = >>>>>>> +                                                pdata->regulators[i].initdata; >> >> In case we have a list of 5 regulators only in pdata, than what will >> happen here when i > 5 ??? >> > > > You're right, it has bug. How do you think that change the condition to > (pdata && i < pdata->num_regulators)? > >>>>>> >>>>>> I  think we can directly use  pdata->regulators[i].initdata instead of >>>>>> init_data[i]. >>>>>> In case if pdata is not their we can use same instance of >>>>>> init_data(default)  for all regulators. >>>>>> >>>>> >>>>> >>>>> This if for some situation that pdata's initdata doensn't line up. When >> >>>>>>> +               config.init_data = init_data[i]; >>>>>>> +               rdev[i] = regulator_register(®ulators[i], &config); >> >> In case pdata->regulators[0] is not the first regulator(i.e id > 0), then >> will it get proper initdata for regulators[0] before registering ???? >> > > > Yes, because above code replaces pdata->regalator's initdata to proper > position of initdata array referencing regulator's id. > >>>> >>>> Ok, but I think this not right place for sorting (sorting is not taking >>>> place.) You have to sort it before entering in loop for registering >>>> regulators. >>>> >>>>> user sets only initdata considered it being used, there may be >>>>> regulators not having initdata, also its order is not clear. So for >>>> >>>> Ok, I think this is a bug in present driver also, because >>>> without checking pdata->num_regulators, you are running in >>>> loop  for (i = 0; i < MAX77686_REGULATORS; i++) >>>> where MAX77686_REGULATORS should be equal to >>>> pdata->num_regulators for this driver to work fine. >>>> >>> >>> >>> I think we have same variable num_regulators but use differently. In my >>> code, it represents number of regulators to be used actually, but in >>> your code it equals to total number of regulators. Since it has >> >> not exactly. >> >>> different meaning, it doesn't have to same with MAX77686_REGULATORS. >>> MAX77686_REGULATORS is macro which indicates total number of regulators >>> in max77686, and it equals to ARRAY_SIZE(regulators). Even if they are >>> not same, it's not a bug because we want to register all regulators >>> whether it will be used or not. >>> >>> >>>> If we consider a case pdata->num_regulators is >>>> equal to MAX77686_REGULATORS and initdata is >>>> not their(i.e. NULL) than I think it will initialise >>>> init_data[pdata->regulators[i].id to NULL, which again will be a bug. >>>> >>>>> those state, i think just using temporary array which satisfies >>>>> regulator's id order is fine while it can't use pdata's initdata directly. >>>>> >>>> >>>> If I am not wrong, I think we can also sort pdata's initdata also using >>>> kernel's sort api and use one instance of (default)initdata for >>>> all unused or uninitialized regulators in platform file. >>>> >>> >>> >>> If init_data references to NULL, it will be ignored while >>> register_regulators() does initialize. Thus it doesn't make any problem. >>> >>> I'm afraid of using Kernel's sort API because of its overhead. Do you >> >> I don't think it's overhead will matter more than that of allocating a >> new array and than >> sorting it here. >> >>> think it will be better to use them? If you mind that init_data has been >>> dynamic allocated, it can be modified to a static pointer array. >>> >> >> No, their is no problem with dynamic. >> Anyways, I had just suggested you to use pdata->regulators[i].initdata. >> > > > So, to sum up to this, you think it is better to sort pdata->regulators > by its id before entering loop and just use pdata->regulators directly, > right? Okay, I'll do modify it. > > >>  Regards, >>  Yadwinder. >> -- >> To unsubscribe from this list: send the line "unsubscribe linux-kernel" in >> the body of a message to majordomo@vger.kernel.org >> More majordomo info at  http://vger.kernel.org/majordomo-info.html >> Please read the FAQ at  http://www.tux.org/lkml/ >> > > -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/