Re: [PATCH] m68k: atari: Make Atari ROM port I/O write macros return void

[Michael Schmitz]

Hi Guenter,

I wish I knew of a way to fix this mess for good... suggestions would be 
welcome.

Looks like you spotted the last remaining macros without a void cast 
here, thanks.

FWIW:
Reviewed-by: Michael Schmitz <schmitzmic@xxxxxxxxx>


Am 21.05.2022 um 02:52 schrieb Guenter Roeck:
> On 5/20/22 07:32, Geert Uytterhoeven wrote:
> > The macros implementing Atari ROM port I/O writes do not cast away their
> > output, unlike similar implementations for other I/O buses.
> > When they are combined using conditional expressions in the
> > definitions of
> > outb() and friends, this triggers sparse warnings like:
> >
> >      drivers/net/appletalk/cops.c:382:17: error: incompatible types in
> > conditional expression (different base types):
> >      drivers/net/appletalk/cops.c:382:17:    unsigned char
> >      drivers/net/appletalk/cops.c:382:17:    void
> >
> > Fix this by adding casts to "void".
> >
> > Reported-by: kernel test robot <lkp@xxxxxxxxx>
> > Reported-by: Guenter Roeck <linux@xxxxxxxxxxxx>
> > Signed-off-by: Geert Uytterhoeven <geert@xxxxxxxxxxxxxx>
>
> Reviewed-by: Guenter Roeck <linux@xxxxxxxxxxxx>
>
> > ---
> > Survived m68k/allmodconfig.
> > To be queued in the m68k tree for v5.19.
> >
> > Removing the casts instead causes issues with functions propagating void
> > return values (return expression in void function), which BTW sparse
> > complains about, too.
>
> We live and learn. I didn't even know that this was valid syntax.
> I thought it might be easier to just fix that code, but coccinelle
> reports that there are hundreds of places in the kernel where this
> is done. Outch.
>
> Guenter