Re: [PATCH net-next v5 1/5] rust: core abstractions for network PHY drivers

[Andrew Lunn <andrew@lunn.ch>]

> +    /// Reads a given C22 PHY register.
> +    pub fn read(&mut self, regnum: u16) -> Result<u16> {
> +        let phydev = self.0.get();
> +        // SAFETY: `phydev` is pointing to a valid object by the type invariant of `Self`.
> +        // So an FFI call with a valid pointer.
> +        let ret = unsafe {
> +            bindings::mdiobus_read((*phydev).mdio.bus, (*phydev).mdio.addr, regnum.into())

If i've understood the discussion about &mut, it is not needed here,
and for write. Performing a read/write does not change anything in
phydev. There was mention of statistics, but they are in the mii_bus
structure, which is pointed to by this structure, but is not part of
this structure.

> +        };
> +        if ret < 0 {
> +            Err(Error::from_errno(ret))
> +        } else {
> +            Ok(ret as u16)
> +        }
> +    }
> +
> +    /// Writes a given C22 PHY register.
> +    pub fn write(&mut self, regnum: u16, val: u16) -> Result {
> +        let phydev = self.0.get();
> +        // SAFETY: `phydev` is pointing to a valid object by the type invariant of `Self`.
> +        // So an FFI call with a valid pointer.
> +        to_result(unsafe {
> +            bindings::mdiobus_write((*phydev).mdio.bus, (*phydev).mdio.addr, regnum.into(), val)
> +        })
> +    }
> +
> +    /// Reads a paged register.
> +    pub fn read_paged(&mut self, page: u16, regnum: u16) -> Result<u16> {

From my reading of the code, read_paged also does not modify phydev.

     Andrew