Re: [PATCH v4 05/41] counter: add HAS_IOPORT dependencies

[Niklas Schnelle <schnelle@linux.ibm.com>]

On Fri, 2023-05-19 at 15:17 +0200, Niklas Schnelle wrote:
> On Thu, 2023-05-18 at 21:26 -0400, William Breathitt Gray wrote:
> > On Tue, May 16, 2023 at 01:00:01PM +0200, Niklas Schnelle wrote:
> > > In a future patch HAS_IOPORT=n will result in inb()/outb() and friends
> > > not being declared. We thus need to add HAS_IOPORT as dependency for
> > > those drivers using them.
> > > 
> > > Co-developed-by: Arnd Bergmann <arnd@kernel.org>
> > > Signed-off-by: Arnd Bergmann <arnd@kernel.org>
> > > Signed-off-by: Niklas Schnelle <schnelle@linux.ibm.com>
> > 
> > Hi Niklas,
> > 
> > The change itself is fine, but please update the description to reflect
> > that this is adding a depends on HAS_IOPORT_MAP rather than HAS_IOPORT,
> > along with the reason why it's needed (i.e. devm_ioport_map() is used).
> > 
> > Thanks,
> > 
> > William Breathitt Gray
> > 
> > 
> 
> Right, this clearly needs adjustment. I went with the following commit
> message for v5:
> 
> "counter: add HAS_IOPORT_MAP dependency
> 
> The 104_QUAD_8 counter driver uses devm_ioport_map() without depending
> on HAS_IOPORT_MAP. This causes compilation to fail on platforms such as
> s390 which do not support I/O port mapping. Add the missing
> HAS_IOPORT_MAP dependency to fix this."
> 

Just noticed this isn't entirely correct. As devm_ioport_map() has an
empty stub for HAS_IOPORT_MAP=n this doesn't lead to a compile error it
just doesn't work. Will reword to "This causes the driver to not be
useable on platforms ..."