RE: [EXT] Re: [PATCH net-next v2 4/4] net: mvpp2: 2500baseX support

[Stefan Chulski <stefanc@marvell.com>]

> -----Original Message-----
> From: Antoine Tenart [mailto:antoine.tenart@free-electrons.com]
> Sent: Wednesday, January 03, 2018 5:32 PM
> To: Andrew Lunn <andrew@lunn.ch>
> Cc: Antoine Tenart <antoine.tenart@free-electrons.com>;
> davem@davemloft.net; kishon@ti.com; gregory.clement@free-electrons.com;
> linux@armlinux.org.uk; mw@semihalf.com; Stefan Chulski
> <stefanc@marvell.com>; Yan Markman <ymarkman@marvell.com>;
> thomas.petazzoni@free-electrons.com; miquel.raynal@free-electrons.com;
> Nadav Haklai <nadavh@marvell.com>; netdev@vger.kernel.org; linux-
> kernel@vger.kernel.org
> Subject: [EXT] Re: [PATCH net-next v2 4/4] net: mvpp2: 2500baseX support
> 
> External Email
> 
> ----------------------------------------------------------------------
> Hi Andrew,
> 
> On Wed, Jan 03, 2018 at 04:20:36PM +0100, Andrew Lunn wrote:
> > > @@ -4612,6 +4616,9 @@ static int mvpp22_comphy_init(struct
> mvpp2_port *port)
> > >  	case PHY_INTERFACE_MODE_1000BASEX:
> > >  		mode = PHY_MODE_SGMII;
> > >  		break;
> > > +	case PHY_INTERFACE_MODE_2500BASEX:
> > > +		mode = PHY_MODE_2500SGMII;
> > > +		break;
> >
> > I think this is the source of confusion with linux/phy.h and
> > linux/phy/phy.h.
> >
> > What would PHY_INTERFACE_MODE_2500SGMII use?
> >
> > Where is this all getting confused? Should the caller to
> > mvpp22_comphy_init() actually be passing
> PHY_INTERFACE_MODE_2500SGMII?
> > What is the MAC actually doing at this point? 2500BASEX or 2500SGMII?
> 
> PHY_INTERFACE_MODE_2500BASEX is the PHY mode whereas
> PHY_MODE_2500SGMII is the mode used by the common PHY driver (i.e. the
> one configuring the serdes lanes).
> 
> There's no PHY_INTERFACE_MODE_2500SGMII mode.
> 
> > At minimum there needs to be a comment that this is not a typ0,
> > otherwise you are going to get patches submitted to 'fix' this.
> 
> Sure, I can add a comment to state this function is a translation between the
> net PHY mode and the generic PHY mode (it's a n-to-1 translation).
> 

Maybe we should rename enum phy_mode to comphy_mode and PHY_MODE_2500SGMII to COMPHY_MODE_2500SGMII.
Since this enum set MAC to PHY serdes communication mode, not PHY to PHY communication mode.

Stefan.