Re: [PATCH 2/3] leds: simatic-ipc-leds-gpio: split up into multiple drivers

[Henning Schild <henning.schild@siemens.com>]

Am Wed, 1 Mar 2023 15:53:04 +0100
schrieb Hans de Goede <hdegoede@redhat.com>:

> Hi,
> 
> On 2/21/23 15:51, Andy Shevchenko wrote:
> > On Tue, Feb 21, 2023 at 03:43:54PM +0100, Henning Schild wrote:  
> >> Am Tue, 21 Feb 2023 15:51:03 +0200
> >> schrieb Andy Shevchenko <andriy.shevchenko@linux.intel.com>:  
> >>> On Tue, Feb 21, 2023 at 01:24:13PM +0100, Henning Schild wrote:  
> >>>> In order to clearly describe the dependencies between the gpio
> >>>>  
> > 
> > ...
> >   
> >>>> +#ifndef __DRIVERS_LEDS_SIMPLE_SIMATIC_IPC_LEDS_GPIO
> >>>> +#define __DRIVERS_LEDS_SIMPLE_SIMATIC_IPC_LEDS_GPIO    
> >>>  
> >>>> +#endif /* __DRIVERS_LEDS_SIMPLE_SIMATIC_IPC_LEDS_GPIO */    
> >>>
> >>> This header doesn't look right.
> >>>
> >>> Have you run `make W=1 ...` against your patches?  
> >>
> >> No reports.
> >>  
> >>> Even if it doesn't show defined but unused errors
> >>> the idea is that this should be a C-file, called,
> >>> let's say, ...-core.c.  
> >>
> >> When i started i kind of had a -common.c in mind as well. But then
> >> the header idea came and i gave it a try, expecting questions in
> >> the review.
> >>
> >> It might be a bit unconventional but it seems to do the trick
> >> pretty well. Do you see a concrete problem or a violation of a
> >> rule?  
> > 
> > Exactly as described above. The header approach means that *all*
> > static definitions must be used by each user of that file.
> > Otherwise you will get "defined but not used" compiler warning.
> > 
> > And approach itself is considered (at least by me) as a hackish way
> > to achieve what usually should be done via C-file.
> > 
> > So, if maintainers are okay, I wouldn't have objections, but again
> > I do not think it's a correct approach.  
> 
> I agree with Andy here, please add a -common.o file with a shared
> probe() helper which gets the 2 different gpiod_lookup_table-s
> as parameter and then put the actual probe() function calling
> the helper inside the 2 different .c files.
> 
> And all the:
> 
> +static struct platform_driver simatic_ipc_led_gpio_driver = {
> +	.probe = simatic_ipc_leds_gpio_probe,
> +	.remove = simatic_ipc_leds_gpio_remove,
> +	.driver = {
> +		.name = KBUILD_MODNAME,
> +	},
> +};
> +
> +module_platform_driver(simatic_ipc_led_gpio_driver);
> +
> +MODULE_LICENSE("GPL v2");
> +MODULE_ALIAS("platform:" KBUILD_MODNAME);
> 
> bits should then also go into the 2 different .c file files.
> 
> Really putting something like module_platform_driver() or
> MODULE_LICENSE() / MODULE_ALIAS() inside a .h file is
> just wrong IMHO.

Thanks for getting back, after Andys review i happen to have just that
already prepared for v2 as "likely needed". Will send that v2 soon.

Henning

> Regards,
> 
> Hans
>