RE: [PATCH 1/2] pinctrl: imx: Support building SCU pinctrl driver as module

[Anson Huang]

Hi, Arnd

> Subject: Re: [PATCH 1/2] pinctrl: imx: Support building SCU pinctrl driver as
> module
> 
> On Fri, Jul 17, 2020 at 11:24 AM Anson Huang <anson.huang@xxxxxxx>
> wrote:
> > > Subject: Re: [PATCH 1/2] pinctrl: imx: Support building SCU pinctrl
> > > driver as module
> > > +MODULE_AUTHOR("Dong Aisheng<aisheng.dong@xxxxxxx>");
> > > +MODULE_DESCRIPTION("NXP i.MX SCU common pinctrl driver");
> > > +MODULE_LICENSE("GPL v2");
> > >
> > >
> > > This can be in a separate patch.
> >
> > I don't understand, without adding module license, changing the SCU
> > pinctrl driver to "tristate", when building with =M, the build will
> > have warning as below, so I think it does NOT make sense to split it to 2
> patches.
> >
> >   CC [M]  drivers/pinctrl/freescale/pinctrl-scu.o
> >   MODPOST Module.symvers
> > WARNING: modpost: missing MODULE_LICENSE() in
> drivers/pinctrl/freescale/pinctrl-scu.o
> >   LD [M]  drivers/pinctrl/freescale/pinctrl-scu.ko
> 
> I agree it would be clearer to do it as separate patches, but you then have to
> be careful about the order to avoid the problem you mention.
> 
> A clear indication that it may be sensible to split up the patch is that your
> changelog has a list of five items in it, which are mostly doing different things.
> The ideal way to split up a patch series is to have each patch with a changelog
> that has to explain exactly one thing, and makes it obvious how each changed
> line corresponds to the description, but never explain the same thing in more
> than one patch (i.e. you combine patches that do the same thing in multiple
> files).
> 
> In this case, a good split may be:
> 
> patch 1:
>    - Use function callbacks for SCU related functions in pinctrl-imx.c
>       in order to support the scenario of PINCTRL_IMX is built in
>       while PINCTRL_IMX_SCU is built as module;
>     - All drivers using SCU pinctrl driver need to initialize the
>       SCU related function callback;
> 
> patch 2:
>     - Export SCU related functions and use "IS_ENABLED" instead of
>       "ifdef" to support SCU pinctrl driver user and itself to be
>       built as module;
>     - Change PINCTR_IMX_SCU to tristate;
>     - Add module author, description and license.
> 
> and then rewrite the description to not have a bulleted list.
> 
> That said, I don't think it is critical here, and I would not have complained
> about the version you sent.
> 
> If you end up changing the patch, I think you can actually drop the "#if
> IS_ENABLED()" check entirely, as the functions are now always assumed to be
> available, and we don't #ifdef declarations when there is no #else path
> otherwise.
> 

Thanks for the good suggestion, if there is other comment need a V2, or maintainer
thinks it is better to split it following your guide, I will send V2 following your guide.

Thanks,
Anson