T1024 on MPX1024: Ethernet not working when cable is plugged in at boot

[u8dde08]

Hello everyone,

I have an issue getting the RGMII1 interface on T1024 working properly.

Whenever I boot from u-boot to linux with the ethernet cable unplugged and then proceed to plug in the cable once linux is waiting for a network connection, everything works fine (allthough the MAC address differs from the one u-boot is using). I can ping the connected host computer and do everything I need to.

BUT: If I boot with the cable plugged in, it configures eth0 with an IP, but the communication does not work. Neither party receives ping replies, wireshark displays nothing.

Thanks for your help!

Details:
- I'm using a MPX1024 module from microsys on a SBC1024 baseboard.
- I've built linux with LSDK 20.12 and Yocto 3.1 (fsl-image-networking)
- The u-boot bootloader is the original, delivered version and reliably creates a ethernet connection on FM1@RTSEC4 with the MAC address ...:a326.
- Linux dts is configured to use ethernet@e6000, ethernet-phy@3 reg = <0x3>, which is the correct PHY address.
- PHY 0, 1, 2 are only connected on MDIO, not on SGMII
- PHY 3 is connected on RGMII1

[yipingwang]

I didn't reproduce this problem with the attached uImage on my T1024RDB demo board.

You could use the attached uImage to do more verification on your custom board, I built uImage with default configuration in Yocto SDK 3.1 release.

I suspect there is hardware problem with Ethernet PHY(or PHY driver), do you have other custom board to do more verification?

[u8dde08]

Hi yipingwang,

thanks for your help. Unfortunately, I cannot use your image since I'm using a MPX T1024 from microsys, not a T1024RDB. They have different ethernet hardware.

What I forgot to mention before: the original firmware from microsys has working ethernet with no problems. So it's not a hardware problem.

Unfortunately their software is very old and is missing some features we need. Therefore I tried to patch Yocto 3.1 to support MPXT1024 and build a kernel.

Apparently I'm missing some important change though, since the network only works properly when booting the kernel without a cable connected. Even disconnecting and reconnecting the cable once it works will make it stop working.

[yipingwang]

Please do the verification on your target board with my uImage + your dtb.