am3354: how to execute loopback test mode for PHY ?

Hi Eric,

As you can see from running "ifconfig -a", the Local Loopback is the "lo" interface with inet address 127.0.0.1. Ping it:

ping localhost

Best regards,
Miroslav

Hi Miroslav,

I found out that even if I remove the LAN cable from the RJ45 and I didn't turn on any loopback on the PHY transceiver, ping 127.0.0.1 still works.  Moreover, our system has both WiFi and ethernet interfaces.  But, 127.0.0.1 is a single loopback interface.  Hence, I think the 127.0.0.1 loopback interface should be in a higher level inside the Linux.  No packet will be sent out to either WiFi controller nor the PHY transceiver.  Is my understanding correct ?

Eric, I'm sorry I didn't understand you the first time. Try using the "ethtool" command to test your interface:

ethtool -t DEVNAME

Best regards,
Miroslav

Hi Miroslav,

Thanks to your advice !  That's really great.  But, unfortunately, the ethtool coming along with the Linux for my am3354 doesn't support ethtool -t.  It replied "Operation not supported".  Do you know where I can get the version ethtool (no matter executable binary or ipk) that allows me to run 'ethtool -t' ?

The actual response of ethtool -t eth0 is :

root@am335x-evm:~# ethtool -t eth0
Cannot test: Operation not supported

What could the possible reason be ?

Eric, I'm sorry, but it seems like the cpsw driver doesn't support ethtool testing:

root@am335x-evm:~# ethtool -i eth0
driver: TI CPSW Driver v1.0
version: 1.0
firmware-version:
bus-info: cpsw
supports-statistics: no
supports-test: no
supports-eeprom-access: no
supports-register-dump: no
supports-priv-flags: no

Best regards,
Miroslav

Miroslav,

Is there any way to override this setting in cpsw ?  Can I re-enable it by modifying the source codes / compiler switch and then re-compile the kernel ?  This is important to me, because our project gets stuck on the PHY.  We have to overcome it.

Thanks !

Eric, I'll try to escalate this to the factory team and see if they can suggest something.

Best regards,
Miroslav

Miroslav,

Is there any update on how to enable testing in cpsw ?

Looking forward to your reply.

Thanks !

Eric