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@hugovil.com/
> > 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).

Best regards
Uwe