Re: [PATCH v2 3/4] arm64: dts: ti: k3-am654-idk: Add ICSSG Ethernet ports

From: MD Danish Anwar
Date: Fri Sep 22 2023 - 00:33:25 EST


On 21/09/23 21:44, Andrew Lunn wrote:
>> + /* Dual Ethernet application node on PRU-ICSSG0 */
>> + /* Dual Ethernet application node on PRU-ICSSG1 */
>
> Not relevant to this patch, but to the ongoing discussions around
> adding switchdev support.
>
> Are these two PRU-ICSSG instances completely separate? It is
> physically impossible to combine these four ethernet ports in one
> acceleration domain? It will always be two separate switches, and if
> frames need to go from one switch to the other it happens in software?
>

Yes Andrew, these PRU-ICSSG instances are completely separate.
AM654x-IDK has 3 PRU-ICSSG instances (ICSSG0, ICSSG1, ICSSG2). Each
instance has two slices i.e. two physical ports. Totaling the ports
count to 6. The two slices of a single ICSSG instance can be combined in
the same acceleration domain. However ICSSG ports of different instances
can not be combined together.

The switching in firmware can only happen between two ports in the same
instance. To do switching between ports of different ICSSG instance,
switching will be required to be done in software.

> Andrew

--
Thanks and Regards,
Danish