Re: [PATCH v2] parport_pc: Also enable driver for PCI systems

[Sudip Mukherjee]

On Mon, Feb 14, 2022 at 8:16 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.  Notably,
> this includes the s390 arch, which has port I/O accessors that cause
> compilation warnings (promoted to errors with `-Werror'), and there are
> other cases such as the POWER9 PHB4 device, though this one has variable
> port I/O accessors that depend on the particular system.  Also it is not
> clear whether the serial port side of devices enabled by PARPORT_SERIAL
> uses port I/O or MMIO.  Finally Super I/O solutions are always either
> ISA or platform devices.
>
> Make the PARPORT_PC option selectable also for PCI systems then, except
> for the s390 arch, however limit the availability of PARPORT_PC_SUPERIO
> to platforms that enable ARCH_MIGHT_HAVE_PC_PARPORT.  Update platforms
> accordingly for the required <asm/parport.h> header.
>
> Signed-off-by: Maciej W. Rozycki <macro@xxxxxxxxxxx>

Acked-by: Sudip Mukherjee <sudipm.mukherjee@xxxxxxxxx>

Usually parport patches goes via Greg's tree. Adding Greg.

-- 
Regards
Sudip