Re: [RFC 25/32] watchdog: Kconfig: add HAS_IOPORT dependencies

Niklas Schnelle
2021-12-28T10:00:32Z

On Mon, 2021-12-27 at 10:03 -0800, Guenter Roeck wrote:
> On 12/27/21 8:43 AM, 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.
> >
>
> How is the need for HAS_IOPORT determined, when exactly is it needed,
> and when not ?

I mostly used "make allyesconfig" on s390 with the accessors ifdeffed
out (i.e. patch 32) to find where the I/O port accesses were compiled
in. This means that it doesn't find drivers which pull in a HAS_IOPORT
dependency transitively e.g. by depending on x86 or ACPI. It should get
those that use e.g. "|| COMPILE_TEST" though. This might not be ideal
but on the other hand it should catch all those drivers that currently
built with known broken code.

>
> $ git grep -E "inb|inw" drivers/watchdog/ | cut -f1 -d: | sort -u
> drivers/watchdog/acquirewdt.c
> drivers/watchdog/advantechwdt.c
>
---8<---