Re: [PATCH v4 1/2] char: xillybus: Move class-related functions to new xillybus_class.c

[Eli Billauer]

On 21/03/21 14:24, Greg KH wrote:
> > +config XILLYBUS_CLASS
> > >  +	tristate
> > >  +
> > >    config XILLYBUS
> > >    	tristate "Xillybus generic FPGA interface"
> > >    	depends on PCI || OF
> > >    	select CRC32
> > >  +	select XILLYBUS_CLASS
> >      
> depends on, do not select.
>
>    
XILLYBUS and XILLYBUS_PCIE are currently enabled as M in several Linux 
distributions. Making them depend on, rather than select XILLYBUS_CLASS 
is likely to disable the driver in those distributions.

With "select", "make oldconfig" sets XILLYBUS_CLASS to the correct value 
smoothly and silently.

Besides, isn't this the intended use case for "select"? A config symbol 
that doesn't depend on anything else, and solves a technical need to 
compile Y if X is enabled?

Or is there a way to use "depends on" without this problem?

Regards,
   Eli