RE: [PATCH v2 03/10] usb: cdns3: Moves reusable code to separate module

[Pawel Laszczak]

>
>On Tue, Nov 10, 2020 at 11:21:22AM +0000, Peter Chen wrote:
>> On 20-11-10 09:20:54, Pawel Laszczak wrote:
>> > Hi,
>> >
>> > >>
>> > >>  int cdns3_hw_role_switch(struct cdns3 *cdns);
>> > >> -int cdns3_init(struct cdns3 *cdns);
>> > >> -int cdns3_remove(struct cdns3 *cdns);
>> > >> +extern int cdns3_init(struct cdns3 *cdns);
>> > >> +extern int cdns3_remove(struct cdns3 *cdns);
>> > >
>> > >Why add "extern" here and below?
>> > >
>> >
>> > These functions are the API between cdnsp and cdns3 modules.
>> > It's looks like a common approach in kernel.
>> > Many or even most of API function in kernel has "extern".
>> >
>>
>> Even you have not written "extern" keyword, the "extern" is
>> added implicitly by compiler. Usually, we use "extern" for variable
>> or the function is defined at assembly. You could see some
>> "extern" keyword use cases at include/linux/device.h.
>
>We are moving away from using this keyword for functions now, if at all
>possible please.  Only use it for variables, I think checkpatch now
>catches it as well.
>

Ok, I will remove all extern from driver. 
Removing it also will remove checkpatch.pl warmings.

Thanks
Pawel