> This extends the mdio-i2c driver so that when SFP PHY address 17 is used
> (which in mdio-i2c terms corresponds to I2C address 0x51), then this
> different protocol is used for MDIO access.
Hi Marek
I don't see that being very scalable. What happens when the next SFP
comes along which has a different protocol at address 0x51. Since you
can identify the SFP via the EEPROM information, i would prefer you
explicitly tell it to use the rollball protocol when instantiating the
MDIO bus.
> * I2C bus addresses 0x50 and 0x51 are normally an EEPROM, which is
> * specified to be present in SFP modules. These correspond with PHY
> - * addresses 16 and 17. Disallow access to these "phy" addresses.
> + * addresses 16 and 17. Disallow access to 0x50 "phy" address.
> + * Use RollBall protocol when accessing via the 0x51 address.
> */
> static bool i2c_mii_valid_phy_id(int phy_id)
> {
> - return phy_id != 0x10 && phy_id != 0x11;
> + return phy_id != 0x10;
> +}
I'm not sure that is safe. It means that we will scan address 0x11 to
see if there is a PHY there. And if the SFP does have diagnostics
registers, that might be enough that phylib thinks there is a PHY
there.
I think you only need to allow access to 0x11 if rollball protocol has
been enabled.
Andrew
