RE: [PATCH 4/9] RapidIO: Add relation links between RIO device structures

[Bounine, Alexandre]

Micha Nelissen wrote:
> 
> Alexandre Bounine wrote:
> > Create back and forward links between RIO devices. These links are
intended for
> > use by error management and hot-plug extensions.
> 
> As RapidIO is a switched network, the concept of 'previous' and 'next'
> devices is invalid. Perhaps it's just the way they were
> discovered/enumerated, but that does not matter any more at runtime.
Or
> at least, should not matter.
>

Yes, the "previous" and "next" have to be considered in context of
enumeration/discovery.
At runtime, it does not matter for data traffic, but is valuable
information for error recovery
And hot-swap. This provides snapshot of device connections. For example,
when servicing
error-stopped state of link between two switches you need to know
ingress port of far switch on
the link. It may be a problem to read it directly from the device.
Searching through the device list
becomes time consuming as a system size grows.      
 
> > @@ -237,6 +241,7 @@ struct rio_switch {
> >  	u16 hopcount;
> >  	u16 destid;
> >  	u8  inport;
> > +	u8  nports;
> >  	u8 *route_table;
> >  	u32 port_ok;
> 
> This can be extracted from the swpinfo field (which you removed in
> another patch)?
> 
Agreed in response for patch #3

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