Re: [PATCH v2 4/7] thermal: exynos: simplify regulator (de)initialization

[Marek Szyprowski]

On 29.09.2023 13:45, Daniel Lezcano wrote:
> On 29/09/2023 13:03, Marek Szyprowski wrote:
>> On 29.09.2023 12:46, Daniel Lezcano wrote:
>>> On 26/09/2023 13:02, Mateusz Majewski wrote:
>>>> Hi,
>>>>
>>>>> This is not equivalent. If regulator is provided and enable fails, 
>>>>> the
>>>>> old code is nicely returning error. Now, it will print misleading
>>>>> message - failed to get regulator - and continue.
>>>>>
>>>>> While this simplifies the code, it ignores important running
>>>>> condition -
>>>>> having regulator enabled.
>>>>
>>>> Would doing this be correct?
>>>>
>>>> ret = devm_regulator_get_enable_optional(&pdev->dev, "vtmu");
>>>> switch (ret) {
>>>> case 0:
>>>> case -ENODEV:
>>>
>>> Not sure to understand why -NODEV is not an error
>>
>>
>> Because this what devm_regulator_get_enable_optional() returns if no
>> regulator is defined. I also got confused by this a few times.
>
> The code before this change calls devm_regulator_get_optional() which 
> returns -ENODEV too, right ? But there is no special case for this error.
>
> So this change uses devm_regulator_get_enable_optional() and handle 
> the ENODEV as a non-error, so there is a change in the behavior.


It looks that the original code ignores any non-EPROBE_DEFER errors from 
devm_regulator_get_optional(). That's a bug, indeed.


Best regards
-- 
Marek Szyprowski, PhD
Samsung R&D Institute Poland