Re: [PATCH v5 net-next 3/3] net: mscc: ocelot: use bulk reads for stats

[Vladimir Oltean <vladimir.oltean@nxp.com>]

On Tue, Feb 08, 2022 at 08:49:52AM -0800, Colin Foster wrote:
> On Tue, Feb 08, 2022 at 03:45:15PM +0000, Vladimir Oltean wrote:
> > On Tue, Feb 08, 2022 at 07:41:56AM -0800, Colin Foster wrote:
> > > I see that now. It is confusing and I'll clear it up. I never caught
> > > this because I'm testing in a setup where port 0 is the CPU port, so I
> > > can't get ethtool stats. Thanks!
> > 
> > You can retrieve the stats on the CPU port, as they are appended to the
> > ethtool stats of the DSA master, prefixed with "p%02d_", cpu_dp->index.
> > 
> > ethtool -S eth0 | grep -v ': 0' # where eth0 is the DSA master
> 
> Thanks for this hint. I didn't even think to go looking for it since the
> DSA Documenation mentions an "inability to fetch CPU port statistics
> counters using ethtool." I see now that this bullet point is from 2015,
> and probably should be removed entirely.

Yes, that paragraph did not age well, although it is still true in some
sense, just not in that phrasing. You still cannot collect ethtool
statistics for cascade (DSA) ports. Maybe it should be updated.