Re: [PATCH net-next v3 07/10] net: dsa: mv88e6xxx: implement port_link_state for mv88e6250

From: Andrew Lunn
Date: Mon Jun 03 2019 - 11:10:15 EST

On Mon, Jun 03, 2019 at 02:42:20PM +0000, Rasmus Villemoes wrote:
> The mv88e6250 has a rather different way of reporting the link, speed
> and duplex status. A simple difference is that the link bit is bit 12
> rather than bit 11 of the port status register.
> It gets more complicated for speed and duplex, which do not have
> separate fields. Instead, there's a four-bit PortMode field, and
> decoding that depends on whether it's a phy or mii port. For the phy
> ports, only four of the 16 values have defined meaning; the rest are
> called "reserved", so returning {SPEED,DUPLEX}_UNKNOWN seems
> reasonable.
> For the mii ports, most possible values are documented (0x3 and 0x5
> are reserved), but I'm unable to make sense of them all. Since the
> bits simply reflect the Px_MODE[3:0] configuration pins, just support
> the subset that I'm certain about. Support for other setups can be
> added later.

The code looks sensible and covers the most likely scenarios.

Reviewed-by: Andrew Lunn <andrew@xxxxxxx>