iMX8MM ethernet MAC from eFuse

[Jacob_bai]

Hi there,

We have two customized iMX8MM boards, they are using same design, uboot, kernel and device tree as well. We tried to setup eth0 MAC address by burning eFuse. However, one of them can read and setup the MAC correctly and another one won't do that. After checking the boot log from uboot, we found the ethernet@30be0000 registered as eth0 in the uboot on the working board, but it registered as eth-1 on the another one. How could that happen? Any idea for this?

not working log:

Net:

Error: ethernet@30be0000 address not set.

Error: ethernet@30be0000 address not set.
eth-1: ethernet@30be0000

working log:

Net:
Warning: ethernet@30be0000 using MAC address from ROM
eth0: ethernet@30be0000

Please check the full log from the attachments.

[igorpadykov]

Hi Jacob

from log "could not request pin 26 (MX8MM_IOMUXC_ENET_MDC) from group fec1grp"  there may be

possible conflicts with mdio, one can look at uboot imx8mm-evk.dts example

https://source.codeaurora.org/external/imx/uboot-imx/tree/arch/arm/dts/imx8mm-evk.dts?h=imx_v2020.04...

If there are more than one ethernet, each can have mac address as described on

https://stackoverflow.com/questions/32747239/can-u-boot-support-more-than-one-ethernet-port

Best regards
igor

[Jacob_bai]

Hi igor,

Thanks for your quick reply!

Guessing the pin26 is not the problem, since the working board showing that message as well. I think its showing that message because we setup the fec1 to fixed link (but other things are same as imx8mm-evk.dts), and our ethernet switch KSZ9893 is working in the i2c mode not the mdio. I didn't change the fec1grp pins, since I am really new to device tree and the switch is working fine with those settings.

Also about the 2nd ethernet support in the uboot, I am using the same uboot for imx8mm-evk, and there is no ethact in the uboot env. 

Regards,

Jacob

[igorpadykov]

may be also useful to look at

http://www.denx.de/wiki/bin/view/DULG/EthernetDoesNotWork

Best regards
igor

[Jacob_bai · Accepted solution]

Hi Igor,

Thanks for your help!

Finally solved the problem by programming a different mac address to it.

Not sure why it can be burned twice and why the first mac address was not acceptable.