Re: [PATCH RFC net-next] net: phy: add Marvell PHY PTP support [multicast/DSA issues]

From: Richard Cochran <richardcochran@gmail.com>
To: Andrew Lunn <andrew@lunn.ch>
Cc: "Russell King (Oracle)" <linux@armlinux.org.uk>,
	Michael Walle <michael@walle.cc>,
	davem@davemloft.net, f.fainelli@gmail.com, hkallweit1@gmail.com,
	kory.maincent@bootlin.com, kuba@kernel.org,
	maxime.chevallier@bootlin.com, netdev@vger.kernel.org,
	thomas.petazzoni@bootlin.com
Subject: Re: [PATCH RFC net-next] net: phy: add Marvell PHY PTP support [multicast/DSA issues]
Date: Fri, 3 Mar 2023 09:32:49 -0800	[thread overview]
Message-ID: <ZAIvQVm9TAOAjrXo@hoboy.vegasvil.org> (raw)
In-Reply-To: <0c0df176-1fbb-43d5-9fb0-358b3873f4e0@lunn.ch>

On Fri, Mar 03, 2023 at 05:34:35PM +0100, Andrew Lunn wrote:
> > > 4) Some solution to the default choice if there is no DT property.
> > 
> > I thought (4) was what we have been discussing... but the problem
> > seems to be that folk want to drill down into the fine detail about
> > whether PHY or MAC timestamping is better than the other.
> > 
> > As I've already stated, I doubt DT maintainers will wear having a
> > DT property for this, on the grounds that it's very much a software
> > control rather than a hardware description.
> 
> We can argue it is describing the hardware. In that hardware blob X
> has a better implementation of PTP than hardware blob Y. That could be
> because of the basic features of the blob, like resolution, adjustable
> clocks, or board specific features, like temperature compensated
> crystals, etc.

IMO a DTS property is the most user friendly solution, even if it
isn't strictly hardware description.

Thanks,
Richard