Hi all,

The HP300 serial driver has a long-standing configuration issue: when
SERIAL_8250 and HP300 are enabled, but none of HPDCA and HPAPCI is
built-in:

    drivers/tty/serial/8250/8250_hp300.c:24:2: warning: #warning CONFIG_SERIAL_8250 defined but neither CONFIG_HPDCA nor CONFIG_HPAPCI defined, are you sure? [-Wcpp]
       24 | #warning CONFIG_SERIAL_8250 defined but neither CONFIG_HPDCA nor CONFIG_HPAPCI defined, are you sure?
	  |  ^~~~~~~

This series fixes this by reworking the Kconfig logic to make invalid
configurations impossible, after moving the HP300 serial suboptions to
where they really belong.  It is meant as a replacement for "[PATCH]
m68k: make HPDCA and HPAPCI bools" [1], and was compile-tested only.

Anyone who can test this one real hardware?
Probably we should add the following to hp300_defconfig:

    +CONFIG_SERIAL_8250=y
    +# CONFIG_SERIAL_8250_DEPRECATED_OPTIONS is not set
    +# CONFIG_SERIAL_8250_16550A_VARIANTS is not set
    +CONFIG_SERIAL_8250_CONSOLE=y
    +CONFIG_SERIAL_8250_HPDCA=y
    +CONFIG_SERIAL_8250_HPAPCI=y

Thanks for your comments!

[1] https://lore.kernel.org/all/20250822104208.751191-1-jirislaby@kernel.org

Geert Uytterhoeven (2):
  tty: serial: 8250: Move HP300/400 serial Kconfig options
  tty: serial: 8250: Rework HP300 serial Kconfig logic

 arch/m68k/Kconfig.devices            | 14 -------------
 drivers/tty/serial/8250/8250_hp300.c | 30 ++++++++++++----------------
 drivers/tty/serial/8250/Kconfig      | 16 ++++++++++++++-
 3 files changed, 28 insertions(+), 32 deletions(-)

-- 
2.43.0

Gr{oetje,eeting}s,

						Geert

--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org

In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
							    -- Linus Torvalds

On Mon, 8 Sept 2025 at 11:45, Geert Uytterhoeven <geert@linux-m68k.org> wrote:
> The HP300 serial driver has a long-standing configuration issue: when
> SERIAL_8250 and HP300 are enabled, but none of HPDCA and HPAPCI is
> built-in:
>
>     drivers/tty/serial/8250/8250_hp300.c:24:2: warning: #warning CONFIG_SERIAL_8250 defined but neither CONFIG_HPDCA nor CONFIG_HPAPCI defined, are you sure? [-Wcpp]
>        24 | #warning CONFIG_SERIAL_8250 defined but neither CONFIG_HPDCA nor CONFIG_HPAPCI defined, are you sure?
>           |  ^~~~~~~
>
> This series fixes this by reworking the Kconfig logic to make invalid
> configurations impossible, after moving the HP300 serial suboptions to
> where they really belong.  It is meant as a replacement for "[PATCH]
> m68k: make HPDCA and HPAPCI bools" [1], and was compile-tested only.
>
> Anyone who can test this one real hardware?
> Probably we should add the following to hp300_defconfig:

Scrap it, this doesn't work for the modular case, due to the #ifdefs
in the driver, which should be converted to #if IS_REACHABLE()...

Sorry for the noise...

Gr{oetje,eeting}s,

                        Geert

-- 
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org

In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
                                -- Linus Torvalds