AnsweredAssumed Answered

Ethernet frequency not stable when boot up

Question asked by Taehyuk Kwon on Apr 7, 2020
Latest reply on Apr 7, 2020 by igorpadykov


I am working with IMX6D Android nougat build,  7.1.2 1.1.1-rc2-2.2. 

I have an issue on the Ethernet. 

During the startup of a board, the 50MHz reference PHY clock, which is generated by the Host processor and sent to the Ethernet PHY chip, turns on at the correct 50MHz for about 3 seconds, then becomes 125MHz (!?) for about 1 second, then turns off momentarily, then resumes at 50MHz.
I guess that the u-boot configures the Ethernet and wait for 3 seconds. It coincides the behavior of  the above clock freq changes. It seems like right after jumping to the kernel, the clock settings stays unknown state. 
We don't see the issue on the Jellybean Android build.
Have you guys seen this kind of issue ? any solution to this ?
Thanks and Regards,
Taehyuk Kwon