Re: [PATCH net-next v2 4/4] net: dsa: soce: Add basic support for SoC-e switch IP cores

[Andrew Lunn]

Thanks for this list.

> ---
> Global register block at 0x0000 (three registers currently used)
> 	0x00 Core Version - Major and minor revision number (RO)
> 	0x04 Licensed Features (RO)
> 	0x08 Reserved
> 	0x0C GUI Configuration - Implemented Features 0 (RO)
> 	0x10 GUI Configuration - Implemented Features 1 (RO)

GUI? I assume this is not Graphical User Interface, but something
else?

> 	Licensed Features Register (RO) (Bits specify if the given
> 	feature is enabled by license):
> 	[31:27] - Maximum Number of Ports: These bits specify the maximum
> 	number of ports licensed
> 	[26:15] - Reserved
> 	- ACL: Access Control List (ACL) feature
> 	- LLDP: LLDP feature
> 	- IEEE 802.1X
> 	- IEEE 802.1AX-2008 - Link Aggregation
> 	- IEEE 802.3br/IEEE 802.1Qbu - Preemption
> 	- IEC 61158-4-2 - DLR
> 	- IEC 62439-2 - MRP
> 	- IGMP Snooping
> 	- Port mirroring
> 	- IEEE 802.1s - MSTP
> 	- IEEE 802.1w - RSTP
> 	- IEEE 1588 - Transparent Clock
> 	- Switch mode: managed or unmanaged

This is probably something which should be tested in the probe
method. No point loading the driver if it cannot be managed.

> 	- Secure Chip
> 	- Time Limitation

What do these two mean?

> 	MDIO - Control
> 	[26:16] - Bus selection: These bits specify the port number over
> 	which MDIO operation is performed.

10 bits, which allows more MDIO busses than ports!

> > I also wounder at the name. Does the data sheet really call it DSA?
> > 
> 
> Yes, there is even a chapter describing Distributed Switch Architecture
> (DSA) as "a subsystem that was primarily designed to support specific
> vendor switches using Linux, ..." followed by information about "custom
> DSA tagging".

Does the switch support the D in DSA?

> Yes, I agree that a feature structure will be needed once more fields
> are used. I would prefer to keep the current interface for now and
> introduce struct soce_features when another detected feature needs to be
> retained. At the moment, it would contain only a single member.

O.K.

	Andrew