Re: [PATCH net] net: dsa: mv88e6xxx: power serdes on/off for 10G interfaces on 6390X

[Andrew Lunn]

On Thu, Feb 28, 2019 at 10:14:33PM +0100, Maxime Chevallier wrote:
> Upon setting the cmode on 6390 and 6390X, the associated serdes
> interfaces must be powered off/on.
> 
> Both 6390X and 6390 share code to do so, but it currently uses the 6390
> specific helper mv88e6390_serdes_power() to disable and enable the
> serdes interface.
> 
> This call will fail silently on 6390X when trying so set a 10G interface
> such as XAUI or RXAUI, since mv88e6390_serdes_power() internally grabs
> the lane number based on modes supported by the 6390, and returns 0 when
> getting -ENODEV as a lane number.
> 
> Using mv88e6390x_serdes_power() should be safe here, since we explicitly
> rule-out all ports but the 9 and 10, and because modes supported by 6390
> ports 9 and 10 are a subset of those supported on 6390X.
> 
> This was tested on 6390X using RXAUI mode.
> 
> Fixes: 364e9d7776a3 ("net: dsa: mv88e6xxx: Power on/off SERDES on cmode change")
> Signed-off-by: Maxime Chevallier <maxime.chevallier@xxxxxxxxxxx>

Reviewed-by: Andrew Lunn <andrew@xxxxxxx>

    Andrew