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

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Date:   Tue, 13 Aug 2019 12:42:55 +0530
From:   Nishka Dasgupta <nishkadg.linux@...il.com>
To:     Roger Quadros <rogerq@...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 13/08/19 11:55 AM, Roger Quadros wrote:
> 
> 
> 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.

Okay, I'll fixup and send v2. What about sysc_check_children()? If error 
variable is removed then sysc_check_children also only returns 0.
Thanking you,
Nishka


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