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

From: Jiri Slaby

Date: Mon Oct 19 2026 - 04:16:04 EST


On 16. 10. 26, 14:59, Arnd Bergmann wrote:
From: Arnd Bergmann <arnd@xxxxxxxx>

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.

Link: https://mirrors.nycbug.org/pub/The_Unix_Archive/Unix_Usenet/comp.unix.sysv386/1990-December/007174.html
Fixes: a300273c458c ("serial: 8250: hub6: Add cleanup code")
Fixes: c526404a4a92 ("serial: 8250: Fix corner case for port matching")
Fixes: 7ab80d1e7243 ("serial: 8250: fix compile error with hub6_match_port() when compiled as a module")
Fixes: da7b5fd4e17f ("serial: 8250_hub6: add missing include for hub6_match_port()")
Fixes: 3d406299d882 ("serial: 8250_hub6: add hub6_match_port()")
Signed-off-by: Arnd Bergmann <arnd@xxxxxxxx>
---
drivers/tty/serial/8250/8250.h | 15 -------
drivers/tty/serial/8250/8250_core.c | 2 -
drivers/tty/serial/8250/8250_hub6.c | 60 -------------------------
drivers/tty/serial/8250/8250_platform.c | 11 +----
drivers/tty/serial/8250/8250_port.c | 23 ----------
drivers/tty/serial/8250/Kconfig | 15 ++-----
drivers/tty/serial/8250/Makefile | 1 -
drivers/tty/serial/atmel_serial.c | 2 -
drivers/tty/serial/fsl_lpuart.c | 2 -
drivers/tty/serial/imx.c | 2 -
drivers/tty/serial/mpc52xx_uart.c | 3 +-
drivers/tty/serial/sa1100.c | 2 -
drivers/tty/serial/serial_core.c | 18 +++-----
drivers/tty/serial/sunsu.c | 9 ----
drivers/tty/serial/xilinx_uartps.c | 2 -
include/linux/serial_8250.h | 2 -
include/linux/serial_core.h | 2 -
17 files changed, 12 insertions(+), 159 deletions(-)
delete mode 100644 drivers/tty/serial/8250/8250_hub6.c

Great, you would have saved me a headache if you had sent these long time ago ;).

So I will Ack both, once you repost with the reported issues fixed.

thanks,
--
js
suse labs