Re: [PATCH] parport_pc: Also enable driver for PCI systems

[Geert Uytterhoeven]

Hi Maciej,

CC Niklas

On Sun, Feb 13, 2022 at 1:45 PM Maciej W. Rozycki <macro@xxxxxxxxxxx> wrote:
> Nowadays PC-style parallel ports come in the form of PCI and PCIe option
> cards and there are some combined parallel/serial option cards as well
> that we handle in the parport subsystem.  There is nothing in particular
> that would prevent them from being used in any system equipped with PCI
> or PCIe connectivity, except that we do not permit the PARPORT_PC config
> option to be selected for platforms for which ARCH_MIGHT_HAVE_PC_PARPORT
> has not been set for.
>
> The only PCI platforms that actually can't make use of PC-style parallel
> port hardware are those newer PCIe systems that have no support for I/O
> cycles in the host bridge, required by such parallel ports.  An example
> of such a host bridge is the POWER9 PHB4 device, but it is an exception
> rather than the norm.  Also it is not clear whether the serial port side

Note that this hardware dependency is being addressed in
"[RFC 00/32] Kconfig: Introduce HAS_IOPORT and LEGACY_PCI options"
https://lore.kernel.org/all/20211227164317.4146918-1-schnelle@xxxxxxxxxxxxx/

> --- linux-macro.orig/drivers/parport/Kconfig
> +++ linux-macro/drivers/parport/Kconfig
> @@ -42,7 +42,7 @@ if PARPORT
>
>  config PARPORT_PC
>         tristate "PC-style hardware"
> -       depends on ARCH_MIGHT_HAVE_PC_PARPORT
> +       depends on ARCH_MIGHT_HAVE_PC_PARPORT || PCI
>         help
>           You should say Y here if you have a PC-style parallel port. All
>           IBM PC compatible computers and some Alphas have PC-style
> @@ -77,7 +77,7 @@ config PARPORT_PC_FIFO
>
>  config PARPORT_PC_SUPERIO
>         bool "SuperIO chipset support"
> -       depends on PARPORT_PC && !PARISC
> +       depends on ARCH_MIGHT_HAVE_PC_PARPORT && PARPORT_PC && !PARISC
>         help
>           Saying Y here enables some probes for Super-IO chipsets in order to
>           find out things like base addresses, IRQ lines and DMA channels.  It
>

Gr{oetje,eeting}s,

                        Geert

--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@xxxxxxxxxxxxxx

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