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From:   Stefan Chulski <stefanc@marvell.com>
To:     Andrew Lunn <andrew@lunn.ch>, Marcin Wojtas <mw@semihalf.com>
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Subject: RE: [EXT] Re: [PATCH v12 net-next 12/15] net: mvpp2: add BM
 protection underrun feature support
Thread-Topic: [EXT] Re: [PATCH v12 net-next 12/15] net: mvpp2: add BM
 protection underrun feature support
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Date:   Sun, 14 Feb 2021 09:20:43 +0000
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> > > Or we have also found out, that pushing back on parameters like
> > > this, the developers goes back and looks at the code, and sometimes
> > > figures out a way to automatically do the right thing, removing the
> > > configuration knob, and just making it all simpler for the user to
> > > use.
> >
> > I think of 2 alternatives:
> > * `ethtool --set-priv-flags` - in such case there is a question if
> > switching this particular feature in runtime is a good idea.
> > * New DT/ACPI property - it is a hardware feature after all, so maybe
> > let the user decide whether to enable it on the platform description
> > level.
>=20
> Does this even need to be configurable? What is the cost of turning it on=
?
> How does having less pools affect the system? Does average latency go up?
> When would i consider an underrun actually a good thing?
>=20
> Maybe it should just be hard coded on? Or we should try to detect when
> underruns are happening a lot, and dynamically turn it on for a while?
>=20
> 	  Andrew

The cost of this change is that=A0the number of pools reduced from 16 to 8.
The current driver uses only 4pools, but some future features like QoS can =
use over 4 pools.=A0

Regards,
Stefan.=A0