Re: [PATCH 1/1] tty: serial: handle HAS_IOPORT dependencies

[Ilpo Järvinen]

On Mon, 8 Apr 2024, Niklas Schnelle wrote:

> On Mon, 2024-04-08 at 12:54 +0300, Ilpo Järvinen wrote:
> > On Fri, 5 Apr 2024, Niklas Schnelle wrote:
> > 
> > > In a future patch HAS_IOPORT=n will disable inb()/outb() and friends at
> > > compile time. We thus need to add HAS_IOPORT as dependency for those
> > > drivers using them unconditionally. For 8250 based drivers some support
> > > MMIO only use so fence only the parts requiring I/O ports.
> > > 
> > > Co-developed-by: Arnd Bergmann <arnd@xxxxxxxxxx>
> > > Signed-off-by: Arnd Bergmann <arnd@xxxxxxxxxx>
> > > Signed-off-by: Niklas Schnelle <schnelle@xxxxxxxxxxxxx>
> > > ---
> > > Note: This patch does not depend any not-yet-mainline HAS_IOPORT changes
> > > and may be merged via subsystem specific trees at your earliest
> > > convenience.
> > > 
> > > Note 2: This was previously acked here:
> > > https://lore.kernel.org/all/2023053050-prodigal-shine-4d1c@gregkh/
> > > Given this was almost a year ago and didn't apply then I didn't
> > > carry the Ack over though.
> > > 
> > > 
> ---8<---
> > > diff --git a/drivers/tty/serial/8250/Kconfig b/drivers/tty/serial/8250/Kconfig
> > > index 47ff50763c04..54bf98869abf 100644
> > > --- a/drivers/tty/serial/8250/Kconfig
> > > +++ b/drivers/tty/serial/8250/Kconfig
> > > @@ -6,7 +6,6 @@
> > >  
> > >  config SERIAL_8250
> > >  	tristate "8250/16550 and compatible serial support"
> > > -	depends on !S390
> > 
> > Why? Your changelogs gives zero insight on this change.
> 
> I used this for compile testing since I build on s390 natively and this
> would have hidden the missing HAS_IOPORT dependencies I'm pretty sure
> it was added because of the I/O port problem too. I'll either add to
> the commit description that it is no longer needed or drop this. Any
> preference?

Okay, we might never know the reason for sure if that's old enough.
I think the best approach would be to put it into own patch so this 
guessimation is limited to a single liner patch instead of it being 
hidden among the other clearer cases.

-- 
 i.