Re: [PATCH net-next v2 05/10] drivers: base: Add device_find_class()

From: Florian Fainelli
Date: Sat Jan 14 2017 - 14:01:24 EST




On 01/13/2017 02:55 AM, David Laight wrote:
> From: Florian Fainelli
>> Sent: 12 January 2017 22:51
>> On 01/12/2017 01:21 PM, David Miller wrote:
>>> From: Florian Fainelli <f.fainelli@xxxxxxxxx>
>>> Date: Wed, 11 Jan 2017 19:41:16 -0800
>>>
>>>> Add a helper function to lookup a device reference given a class name.
>>>> This is a preliminary patch to remove adhoc code from net/dsa/dsa.c and
>>>> make it more generic.
> ...
>>>> +static int dev_is_class(struct device *dev, void *class)
>>>
>>> I know you are just moving code, but this class argumnet is a string
>>> and thus should be "char *" or even "const char *".
>>
>> Well, this is really so that we don't need to cast the arguments passed
>> to device_find_child(), which takes a void *data as well. If we made
>> that a const char *class, we'd get warnings that look like these:
>>
>> drivers/base/core.c: In function 'device_find_class':
>> drivers/base/core.c:2083:2: warning: passing argument 2 of
>> 'device_find_child' discards 'const' qualifier from pointer target type
>> [enabled by default]
>> return device_find_child(parent, class, dev_is_class);
>> ^
>> drivers/base/core.c:2050:16: note: expected 'void *' but argument is of
>> type 'const char *'
>> struct device *device_find_child(struct device *parent, void *data,
>> ^
> ...
>
> Maybe device_find_child() needs changing to take 'const void *' ?

As a separate patch set, sure, I will add that to my TODO. Thanks!
--
Florian