Re: [PATCH net-next v3 8/8] net: dsa: soce: Disable unsupported hardware STP

[Vasilij Strassheim <v.strassheim@linutronix.de>]

On Sat, 2026-09-26 at 01:24 +0200, Andrew Lunn wrote:
> On Wed, Sep 23, 2026 at 12:39:35PM +0200, Vasilij Strassheim wrote:
> > The driver does not implement hardware STP offloading yet.
> 
> What exactly do you mean by STP offload? Can it do the actual
> protocol? No DSA switch can do that, we always use the software
> implementation. I'm not even sure it is possible to offload the actual
> protocol.

That's not a complete offload. The documentation says:
"The Spanning Tree protocols is supported as a mixed hardware and
software solution. In the hardware section, IP core is in charge of
forwarding BPDU frames to/from the CPU port and managing frames
according to the STP port states."
And:
"Spanning Tree (STP/RSTP/MSTP) algorithm runs in a software application
in the CPU. The CPU is in charge of configuring the switch port states
based on the processed BPDU frames."

There are a few registers for this. However, it's enough to just turn
off the feature and use only the software implementation in Linux.

I will update the documentation accordingly and stop using the term
“offloading” to avoid confusion.

> 
> 	Andrew

Thanks,
Vasilij