[PATCH 1/2] tty: serial: remove hub6 multiport support

[Andy Shevchenko]

On Fri, Oct 16, 2026 at 02:59:47PM +0200, Arnd Bergmann wrote:

> hub6 support was added in linux-0.99 and the hardware was already old at
> the time, being discontinued in 1990. The code for it has always been a
> mess since it adds another dimension to the I/O addressing in the driver
> that has leaked into many individual files.
> 
> Hugo and Uwe have attempted several times this year alone to isolate
> the hub6 handling into the 8250_hub6.c file, but I feel that none of
> this has been a real improvement over the original standalone loadable
> module support.
> 
> Any machine that would have used this ISA card in practice is likely
> 30 to 40 years old, and with i486 support now removed, it is clearly
> safe to just kill this all off. The only bit that has to remain
> is the ioctl interface, to ensure the serial_struct field is always
> zero.

After reading patch 2/2 I noticed also a SERIAL_IO_HUB6 leftover. Most likely
it should stay as is until the user space gets rid of the use.

-- 
With Best Regards,
Andy Shevchenko