Re: [PATCH net-next 3/3] net: hns3: add support for link diagnosis info in debugfs

[Andrew Lunn <andrew@lunn.ch>]

> > > Hi Jakub, I have a question to consult you.
> > > Some fault information in our patch are not existed in current ethtool extended
> > > link states, for examples:
> > > "Serdes reference clock lost"
> > > "Serdes analog loss of signal"
> > > "SFP tx is disabled"
> > > "PHY power down"
> > 
> > Why would the PHY be powered down if user requested port to be up?
> > 
> In the case of other user may use MDIO tool to write PHY register directly to make
> PHY power down, if link state can display this information, I think it is helpful.

If the user directly writes to PHY registers, they should expect bad
things to happen. They can do a lot more than power the PHY down. They
could configure it into loopback mode, turn off autoneg and force a
mode which is compatible with the peer, etc.

I don't think you need to tell the user they have pointed a foot gun
at their feet and pulled the trigger.

   Andrew