linux-kernel - Re: [PATCH v4] regulator: MAX77686: Add Maxim 77686 regulator driver

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Date:	Thu, 31 May 2012 18:16:13 +0530
From:	Yadwinder Singh Brar <yadi.brar01@...il.com>
To:	jonghwa3.lee@...sung.com
Cc:	linux-kernel@...r.kernel.org, Liam Girdwood <lrg@...com>,
	Mark Brown <broonie@...nsource.wolfsonmicro.com>,
	Chiwoong Byun <woong.byun@...sung.com>,
	Myungjoo Ham <myungjoo.ham@...sung.com>,
	Kyungmin Park <kyungmin.park@...sung.com>
Subject: Re: [PATCH v4] regulator: MAX77686: Add Maxim 77686 regulator driver

On Thu, May 31, 2012 at 12:26 PM,  <jonghwa3.lee@...sung.com> wrote:
> On 2012년 05월 30일 21:08, Yadwinder Singh Brar wrote:
>
>> Hi Jonghwa,
>>
>> On Wed, May 30, 2012 at 4:07 PM,  <jonghwa3.lee@...sung.com> 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 this stuff is not at right place, It should be moved out of this loop
to solve this both problems.
Please try to do all this stuff rel

>>>>>>
>>>>>> 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(&regulators[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.
>

No, sorry i think you again missed the point.
Anyways, moving above stuff out of this loop
will also sove this problem.

>>>>
>>>> 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.
>>>
>>>


>
> 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.
>

Yes, this will allow us to add device tree support without any
modifications to this code in future and keeping our code simple
and compact.

In my opinion
>>  Regards,
>>  Yadwinder.
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/