the ethernet does not work if the linux console is disabled

[jean-françoistr]

Hello,

when I delete the console in UBoot (console=NULL) and restart my target, the Ethernet ports does not work.
It is important to turn off/on the power supply for the restart.

my research allowed me to understand that it is the registry CCM_CCGR0 that is not well configured.

When the eternet is ok: CCM_CCGR0 =  0xC0C0330F

When the eternet does not work: CCM_CCGR0 = 0xC0C0030F

dmesg:  " fec 2188000.ethernet eth0: Unable to connect to phy "

But, I don't know why and how to correct this difference.

µP: IMX6ULL

Kernel Linux: 4.14.11

Thank you for your help.

[igorpadykov]

Hi  jean-françoistrap

this is expected behaviour as CCM_CCGRn gates clocks for modules,

so gated module can not work. More CCM_CCGRn description can be found in

18.6.23 CCM Clock Gating Register 0 (CCM_CCGR0) i.MX6ULL Reference Manual

http://www.nxp.com/docs/en/reference-manual/IMX6ULLRM.pdf 

Best regards
igor
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