Subject: Re: [PATCH v2] powerpc/83xx: add support for mpc8306

From: Filip Brozović <[email-masked]>
Date: Fri, 03 Apr 2015 14:45:25 +0200

On 4/3/2015 2:01 PM, Paul Bolle wrote:
> On Fri, 2015-04-03 at 12:44 +0200, Filip Brozovic wrote:
>> --- a/arch/powerpc/platforms/83xx/Kconfig
>> +++ b/arch/powerpc/platforms/83xx/Kconfig
>
>> +# used for gpio
>> +config PPC_MPC830x
>> +	bool
>> +	select ARCH_WANT_OPTIONAL_GPIOLIB
>> +
>> +config PPC_MPC8306
>> +	bool
>
> To me these two new Kconfig symbols look pointless:
> - they have no prompt, so one cannot set them manually;
> - no other Kconfig symbol selects them;
> - they do not default to 'y'.
>
> I'm not aware of a way to set these symbols to 'y' outside of those
> three. Is there perhaps a way for kconfig to set these symbols to 'y'
> that I have missed?
>
> Or do you expect to do one of these three things in a separate patch?
>

The idea was that boards in the Kconfig file would select these symbols 
in order to enable support for the 8306. I mainly wanted to get this 
patch into mainline in order to make kernel maintenance for a couple of 
custom in-house developed boards easier. Since these boards are not 
widely available and our customers are unlikely to want to change and 
recompile the kernel, I have so far leaned towards not including support 
for them in mainline. As far as I can see, boards which are included in 
mainline right now are mostly evaluation boards which are easily 
available at most electronics distributors.

That being said, I don't know what the "official" stance on this is; is 
adding custom boards encouraged regardless of their availability (e.g. 
if I develop a custom board with the intention of only ever actually 
making a single prototype for personal use, should I go and submit 
patches so that support makes it into the mainline kernel?), or should 
there be a minimum level of public interest before incorporating custom 
boards into mainline? If it's the latter, I suppose a solution would be 
to include support for the Freescale MPC8306SOM in mainline. Of course, 
this has its own problems, since someone would have to write and 
maintain it (and I don't have an MPC8306SOM nor the time needed to do 
maintenance).

- Filip