5 Replies Latest reply on Feb 23, 2016 6:47 AM by Carlos_A

    Problems with I210 and external PHYs

    PVWB Brown Belt

      Dear All,


      We have a board with two I210 parts on it.

      The I210 communicates with a PHY on a daughter card.

      We have two different types of daughter card.  One has

      a Marvell 88E1111 device and the other has a Marvell 88E1512

      part on it.


      I turned on the debugging messages in the Intel driver software.


      With the 88E1512 board, I see a lot of routines being called,

      but the PHY doesn't get set up correctly.  On power up the

      RJ45 side of the PHY gets linkup to a switch, but not after

      the driver code runs.  So, my question is has this particular

      combination of I210 and PHY been tested recently?  It

      obviously requires a lot of work to test every release of

      software with every possible hardware permutation.


      With the 88E1111 we have problems with getting occasional MDIO errors
      when the I210 is doing MDIO reads.  On reading the code, the
      "MDI Error" message is triggered by the MDI_ERR bit being
      set in the I210's MDIC register (0x20).


      On page 377 of the I210 manual, there is the statement:


      This bit is set to 1b by hardware when it fails to complete an MDI read.
      Software should make sure this bit is clear (0b) before issuing an MDI read
      or write command.


      My question is what triggers the setting of this bit?  The MDIO
      protocol has no handshaking with the MDIO slave.  If there is
      no slave at all, the MDIO master will just drive the read pattern,
      followed by the PHY address and register address.  After that the
      pull-up will pull the MDIO data line high, and all ones will be read.
      How do you get an error?


      Thanks, Paul.

        • Re: Problems with I210 and external PHYs
          Carlos_A Brown Belt

          Hello PVWB,


          Thank you for contacting the Intel Embedded Community.


          We suggest you to follow the suggestions provided to you in the Forum I210 DC Specification #2.


          Best Regards,


          • Re: Problems with I210 and external PHYs
            PVWB Brown Belt

            I think I have figured this out.  It declares an error if it

            ever reads all ones, as happens when the MDIO target is

            missing.  I assume you get this error if you read a register

            that really is all ones!


            However, now I have the MDIO transfers working to

            the 88E1111, I find I get a similar behaviour to that

            I had with the 88E1512 parts.  After the code runs,

            the RJ45 link between PHY and the external switch

            goes down.  At power up, the link comes up.  Is it

            possible that there is a problem with the code that

            sets up these PHYs.  I realize that not many people

            use the I210 with an external RJ45 PHY.


            Thanks, Paul.

              • Re: Problems with I210 and external PHYs
                Carlos_A Brown Belt

                Hello PVWB,


                Thanks for your reply.


                In order to better understand this situation, we would like to address the following questions:


                Could you please tell us the Operating System (OS), driver version, NVM image use to talk to these external PHY?


                Could you please inform us know how long are the traces to the PHY?


                Could you please let us know the type of connection is being used?


                Could you please confirm if this design has been looked by Intel?


                These questions have been addressed to have more information of the design and usage model, in order to have a better idea of the problem and give you the proper information.


                It is important to let you know that the 88E1111 is supported with our drivers, we have idea that the 88E1512 is unsupported. In case that you want to work with an unsupported device, you should build your own driver.


                Thanks again for your collaboration.


                Best Regards,


                  • Re: Problems with I210 and external PHYs
                    PVWB Brown Belt

                    Dear Carlos,


                    The two I210 devices starting working on Friday.


                    Here is a summary of what we had to do:


                    We changed the Initialization control word 3 (0x24) from 0x4220
                    to 0x4224.  This turns on the external MDIO mode.  My guess
                    is the original used I2C with an SFP.  We also had to update
                    the checksum.


                    The correct PHY address has to be specified in Flash word 0x13
                    (Initialization control word 4).  This is probably relevant to
                    the other person having trouble with SGMII operation with an
                    SFP. (P 187 of the I210 manual)


                    There is a bug somewhere in the code that powers down the
                    PHY.  This is the 0x800 bit in PHY word 0, for at least the
                    88E1111.  We did the rude hack of adding the following to the
                    e1000_write_phy_reg_mdic routine:


                    if (offset == 0 && (data & 0x800)) data ^= 0x800; // Rude hack


                    This solves the power down problem, if not very elegantly!


                    There is another, probably mostly harmless bug around line 275
                    and 334 of e1000_phy.c.  This puts the PHY address in the register E1000_MDIC,
                    (0x20) (p 376), reserved area.  For the I210, the PHY address
                    is stored in I210 register E1000_MDICNFG, (0xE04) (p 377).
                    The other effect of this is, if code elsewhere changes the value of
                    phy->addr, these changes will not get copied into E1000_MDICNFG,
                    so the address loaded from the Flash will continue to be used
                    for the MDIO transfers.


                    Our starting image was