Re: [PATCH v2 1/4] xen/ns16550: solve compilation error on ARM with CONFIG_HAS_PCI enabled.

[Jan Beulich <jbeulich@xxxxxxxx>]

On 03.11.2020 16:59, Rahul Singh wrote:
> ARM platforms do not have PCI support available. When CONFIG_HAS_PCI
> is enabled for ARM a compilation error is observed for ns16550 driver.

I still don't really agree to the approach taken together with
the wording. If Arm was to select HAS_PCI, my expectation would
be that this file compiled fine. You don't mention what
compilation error it is that results, so it's hard to judge if
I'm completely wrong. If, however, this is just a shortcoming
of the Arm implementation right now, then I'd like to ask that
the description here be worded to this effect. This will then
make it easier to understand that the change here can really
be reverted without much further consideration.

> --- a/xen/drivers/char/Kconfig
> +++ b/xen/drivers/char/Kconfig
> @@ -4,6 +4,13 @@ config HAS_NS16550
>       help
>         This selects the 16550-series UART support. For most systems, say Y.
>  
> +config HAS_NS16550_PCI
> +     def_bool y
> +     depends on X86 && HAS_NS16550 && HAS_PCI
> +     help
> +       This selects the 16550-series UART PCI support.For most systems,
> +       say Y.

There's not much point for a prompt-less option to have help
text. There's definitely no point telling what to select when
really there's nothing to select, due to the lack of a prompt.

Jan