Re: [PATCH] serial: 8250_hub6: Fix double definition for hub6_match_port()

[Hugo Villeneuve]

On Mon, 27 Jul 2026 11:22:10 -0400
Hugo Villeneuve <hugo@xxxxxxxxxxx> wrote:

> Hi Uwe,
> 
> On Fri, 24 Jul 2026 09:58:13 +0200
> Uwe Kleine-König <u.kleine-koenig@xxxxxxxxxxxx> wrote:
> 
> > On Thu, Jul 23, 2026 at 11:13:59PM -0400, Hugo Villeneuve wrote:
> > > > For me the open question remains if the driver works in the
> > > > configuration CONFIG_SERIAL_8250=y (and thus CONFIG_SERIAL_CORE=y) +
> > > > CONFIG_SERIAL_8250_HUB6=m. In this case at least commit
> > > > 3d406299d8829747fe2e8692f4c29fe3dc1d101f +
> > > > https://lore.kernel.org/linux-serial/20260715153707.4181828-1-hugo@xxxxxxxxxxx/
> > > > introduces a logical change in uart_match_port() that isn't explained in
> > > > the commit log.
> > > 
> > > Not sure what you mean by that logical change?
> > 
> > With said configuration and before
> > 3d406299d8829747fe2e8692f4c29fe3dc1d101f uart_match_port() returned
> > 
> > 	port1->iobase == port2->iobase && port1->hub6 == port2->hub6
> > 
> > and with 3d406299d8829747fe2e8692f4c29fe3dc1d101f (and your fix on top)
> > it returns false (because when drivers/tty/serial/serial_core.c is
> > compiled IS_REACHABLE(CONFIG_SERIAL_8250_HUB6) evaluates to false).
> 
> this change was certainly not intended, sorry about that. Looks like
> there are still subtle Kconfig-isms (and 8250-isms) that I still need to
> master...
> 
> So to be sure i understand this correctly:
> I will submit a patch to replace IS_REACHABLE with IS_ENABLED, which
> means that the configuration CONFIG_SERIAL_8250=y and
> CONFIG_SERIAL_8250_HUB6=m is not supported, as you stated that
> it currently cannot happen?

Or we leave it as is, since this combination is not really valid?

-- 
Hugo Villeneuve