Re: [PATCH v12 4/5] rust: pci: add config space read/write support

["Alexandre Courbot" <acourbot@nvidia.com>]

On Thu Jan 22, 2026 at 5:22 AM JST, Zhi Wang wrote:
<snip>
> +    /// Return an initialized normal (256-byte) config space object.
> +    pub fn config_space<'a>(&'a self) -> Result<ConfigSpace<'a, Normal>> {
> +        Ok(ConfigSpace {
> +            pdev: self,
> +            _marker: PhantomData,
> +        })
> +    }
> +
> +    /// Return an initialized extended (4096-byte) config space object.
> +    pub fn config_space_extended<'a>(&'a self) -> Result<ConfigSpace<'a, Extended>> {
> +        Ok(ConfigSpace {
> +            pdev: self,
> +            _marker: PhantomData,
> +        })
> +    }

Why are we returning a `Result` given that none of these methods can
ever fail? I mentioned that in earlier revisions too [1], but it looks
like we should invoke `cfg_size` to validate the size first, lest we
return a `ConfigSpace` that is larger than what is actually supported.

[1] https://lore.kernel.org/all/DEHUBNKNSNXH.14A4OGQKY5KZR@nvidia.com/#t