RE: [EXT] Re: [V2 net-next] net: mvpp2: Add reserved port private flag configuration

quoted

CM3 won't use this interface till ethtool priv flag was set, it can be done by

communication over CM3 SRAM memory.

quoted

quoted

How does CM3 know the status of the link?

CM3 has access to MAC registers and can read port status bit.

quoted

How does CM3 set its
flow control depending on what auto-neg determines, etc?

Same as PPv2 Packet Processor RX and TX flow don't really care about auto-

neg, flow control, etc.

quoted

CM3 can ignore it, all this stuff handled in MAC layer. CM3 just polling RX

descriptor ring and using TX ring for transmit.

quoted

quoted

quoted

3. In some cases we need to dynamically switch the port "user"
between CM3 and kernel. So I would like to preserve this
functionality.

And how do you synchronize between Linux and CM3 so you know how

is

quoted

quoted

using it and who cannot use it?

      Andrew

I can add CM3 SRAM update into ethtool priv flag callback, so CM3 won't

use port till it was reserved to CM3.

I really think you need to step back here and look at the bigger picture. If
linux should not use the interface, it should not exist. If it does not exist, you
cannot use ethtool on it.

What you might want to consider is adding remoteproc support between
Linux on the main processor and whatever you have on the CM3. You can
use RPMsg to send requests back and forth between Linux and the CM3. It
can request that the shared parts of the packet processor are set up for it.
Linux can tell it when the link comes up? It can request how the PHY auto-
neg should be configured.

	Andrew

I would check this option. 

Thanks,
Stefan.