linux-kernel - Re: [PATCH] bus: ti-sysc: Remove if-block in sysc_check

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Date:   Tue, 13 Aug 2019 09:25:56 +0300
From:   Roger Quadros <rogerq@...com>
To:     Nishka Dasgupta <nishkadg.linux@...il.com>, <tony@...mide.com>,
        <linux-kernel@...r.kernel.org>, "Kristo, Tero" <t-kristo@...com>
Subject: Re: [PATCH] bus: ti-sysc: Remove if-block in sysc_check_children()



On 13/08/2019 07:35, Nishka Dasgupta wrote:
> On 08/08/19 7:25 PM, Roger Quadros wrote:
>> Nishka,
>>
>> On 08/08/2019 10:40, Nishka Dasgupta wrote:
>>> In function sysc_check_children, there is an if-statement checking
>>> whether the value returned by function sysc_check_one_child is non-zero.
>>> However, sysc_check_one_child always returns 0, and hence this check is
>>> not needed. Hence remove this if-block.
>>>
>>> Signed-off-by: Nishka Dasgupta <nishkadg.linux@...il.com>
>>> ---
>>>   drivers/bus/ti-sysc.c | 2 --
>>>   1 file changed, 2 deletions(-)
>>>
>>> diff --git a/drivers/bus/ti-sysc.c b/drivers/bus/ti-sysc.c
>>> index e6deabd8305d..bc8082ae7cb5 100644
>>> --- a/drivers/bus/ti-sysc.c
>>> +++ b/drivers/bus/ti-sysc.c
>>> @@ -637,8 +637,6 @@ static int sysc_check_children(struct sysc *ddata)
>>>         for_each_child_of_node(ddata->dev->of_node, child) {
>>>           error = sysc_check_one_child(ddata, child);
>>> -        if (error)
>>> -            return error;
>>
>> We cannot assume that sysc_check_one_child() will never return error in the future.
>> If it can never return an error then why does it have an int return type?
> 
> I'm not sure why it has an int return type, unfortunately. This is the function in its entirety:
> 
> static int sysc_check_one_child(struct sysc *ddata,
>                 struct device_node *np)
> {
>     const char *name;
> 
>     name = of_get_property(np, "ti,hwmods", NULL);
>     if (name)
>         dev_warn(ddata->dev, "really a child ti,hwmods property?");
> 
>     sysc_check_quirk_stdout(ddata, np);
>     sysc_parse_dts_quirks(ddata, np, true);
> 
>     return 0;
> }
> 
> I'm not sure how to understand this function. Do dev_warn() or sysc_check_quirk_stdout() or sysc_parse_dts_quirks() cause a non-zero return from sysc_check_one_child()? Should I drop my patch?

None of those functions return anything.
Maybe you can fix sysc_check_one_child() to return void?
I think you can retain your patch but get rid of error variable.

> 
> Thanking you,
> Nishka
>>
>>>       }
>>>         return 0;
>>>
>>

-- 
cheers,
-roger
Texas Instruments Finland Oy, Porkkalankatu 22, 00180 Helsinki.
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