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Date:   Sat, 10 Jul 2021 22:47:55 +0300
From:   Vladimir Oltean <olteanv@gmail.com>
To:     Colin Foster <colin.foster@in-advantage.com>
Cc:     andrew@lunn.ch, vivien.didelot@gmail.com, f.fainelli@gmail.com,
        davem@davemloft.net, kuba@kernel.org, robh+dt@kernel.org,
        claudiu.manoil@nxp.com, alexandre.belloni@bootlin.com,
        UNGLinuxDriver@microchip.com, linux@armlinux.org.uk,
        netdev@vger.kernel.org, devicetree@vger.kernel.org,
        linux-kernel@vger.kernel.org
Subject: Re: [RFC PATCH v2 net-next 0/8] Add support for VSC7511-7514 chips
 over SPI
Message-ID: <20210710194755.xmt5jnaanh45dmlm@skbuf>
References: <20210710192602.2186370-1-colin.foster@in-advantage.com>
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On Sat, Jul 10, 2021 at 12:25:54PM -0700, Colin Foster wrote:
> 1. The first probe of the internal MDIO bus fails. I suspect this is related to
> power supplies / grounding issues that would not appear on standard hardware.

Where and with what error code does it fail exactly? I don't understand
the concept of "the first probe"? You mean that there is an
-EPROBE_DEFER and it tries again immediately afterwards? Or you need to
unbind and rebind the driver to the device, or what?

> 2. Communication to the CPU bus doesn't seem to function properly. I suspect
> this is due to the fact that ocelot / felix assumes it is using the built-in CPU
> / NPI port for forwarding, though I am not positive.

What is the CPU bus and what doesn't function properly about it?

> Nonetheless, these two issues likely won't require a large architecture change,
> and perhaps those who know much more about the ocelot chips than I could chime
> in.

I guess you don't know if that's the case or not until you know what the
problem is...