AM6442: Use only one PHY for Enet(ICSS)

Hi Andrean,

Thanks for your query.

Andrean С. said:

Can ICSS ENET use only one PHY(another one is disabled)?

Menas, you want to control 4-Ethernet-ports of (2 of ICSSG0) and (2 of ICSSG1) using single PHY ?

Regards

Ashwani  

I assumed they meant they only need a single Ethernet port, instead of 2 Ethernet ports (i.e., use 1 PRU_ICSSG slice to control one PHY, and don't run any firmware on the other PRU_ICSSG slice).

When PRU Ethernet was first introduced in Linux on AM335x, dual EMAC mode was the only mode that was supported (i.e., 2 Ethernet ports was supported, 1 Ethernet port was NOT supported). In order to run a PRU subsystem in single EMAC mode, we had to do workarounds in order to technically enable both ports in software, but only actually use 1 port in hardware. However, for many years now (and for all AM64x software releases), the Linux PRU Ethernet driver supports a PRU subsystem running in dual EMAC mode, or single EMAC mode.

I'm not sure what it looks like for R5F controlling PRU_ICSSG.

Regards,

Nick

Hello Ashwani,

There is an example in \examples\networking\lwip\enet_lwip_icssg. It uses 2 PHY and two ethernet ports. We have our custom board and need to run the same example, but only one PHY and one ethernet port are available. How should we proceed to enable just one port? Do we need to use the "custom board" checkbox?
 

I'm asking also to see if it can work with just one port. 

Best regards,

Andrean

Hello Ashwani,

Thank you! It worked!

Just a last question: is enabling both ICSSG in DUAL MAC recommended, even if another one is not wired? We've enabled just one, and it seems to work fine.

Best regards,

Andrean

Thanks for having patience as I was out for last couple of days.

Andrean С. said:

is enabling both ICSSG in DUAL MAC recommended

It should not create a problem. Still, I will cross check with dev team and get back to you.

Regards

Ashwani

Andrean С. said:

is enabling both ICSSG in DUAL MAC recommended, even if another one is not wired?

Can you try on your side and let me know if you face any problem?

Regards
Ashwani

Hello Ashwani,

Sorry for the delay. It seems to work fine. We'll continue testing, and if there is a problem, we'll open another question. 

Thank you for the help!

Best regards,

Andrean