Re: [PATCH net] net: dsa: mv88e6xxx: Set correct interface mode for CPU/DSA ports

[Greg Ungerer]

Hi Andrew,

Thanks for the quick response.


On 24/5/19 11:44 pm, Andrew Lunn wrote:

On Fri, May 24, 2019 at 11:25:03AM +1000, Greg Ungerer wrote:

Hi Andrew,

I have a problem with a Marvell 6390 switch that I have bisected
back to commit 7cbbee050c95, "[PATCH] net: dsa: mv88e6xxx: Set correct
interface mode for CPU/DSA ports".

I have a Marvell 380 SoC based platform with a Marvell 6390 10 port
switch, everything works with kernel 5.0 and older. As of 5.1 the
switch ports no longer work - no packets are ever received and
none get sent out.

The ports are probed and all discovered ok, they just don't work.

   mv88e6085 f1072004.mdio-mii:10: switch 0x3900 detected: Marvell 88E6390, 
revision 1
   libphy: mv88e6xxx SMI: probed
   mv88e6085 f1072004.mdio-mii:10 lan1 (uninitialized): PHY [mv88e6xxx-1:01] 
driver [Marvell 88E6390]
   mv88e6085 f1072004.mdio-mii:10 lan2 (uninitialized): PHY [mv88e6xxx-1:02] 
driver [Marvell 88E6390]
   mv88e6085 f1072004.mdio-mii:10 lan3 (uninitialized): PHY [mv88e6xxx-1:03] 
driver [Marvell 88E6390]
   mv88e6085 f1072004.mdio-mii:10 lan4 (uninitialized): PHY [mv88e6xxx-1:04] 
driver [Marvell 88E6390]
   mv88e6085 f1072004.mdio-mii:10 lan5 (uninitialized): PHY [mv88e6xxx-1:05] 
driver [Marvell 88E6390]
   mv88e6085 f1072004.mdio-mii:10 lan6 (uninitialized): PHY [mv88e6xxx-1:06] 
driver [Marvell 88E6390]
   mv88e6085 f1072004.mdio-mii:10 lan7 (uninitialized): PHY [mv88e6xxx-1:07] 
driver [Marvell 88E6390]
   mv88e6085 f1072004.mdio-mii:10 lan8 (uninitialized): PHY [mv88e6xxx-1:08] 
driver [Marvell 88E6390]
   DSA: tree 0 setup

Things like ethtool on the ports seem to work ok, reports link correctly.
Configuring ports as part of a bridge or individually gets the same result.

Hi Greg

DSA by default should configure the CPU port and DSA ports to there
maximum speed. For port 10, that is 10Gbps. Your 380 cannot do that
speed. So you need to tell the switch driver to slow down. Add a fixed
link node to port ten, with speed 1000. You might also need to set the
phy-mode to rgmii.

My hardware has the CPU port on 9, and it is SGMII. The existing working
devicetree setup I used is:

                       port@9 {
                                reg = <9>;
                                label = "cpu";
                                ethernet = <&eth0>;
                                fixed-link {
                                        speed = <1000>;
                                        full-duplex;
                                };
                        };

Can the 380 do 2500BaseX? There is work in progress to support this
speed, so maybe next cycle you can change to that.

That would be nice.

Regards
Greg