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Date:   Mon, 22 Mar 2021 10:44:20 +0200
From:   Cristian Ciocaltea <cristian.ciocaltea@gmail.com>
To:     Florian Fainelli <f.fainelli@gmail.com>
Cc:     "David S. Miller" <davem@davemloft.net>,
        Andrew Lunn <andrew@lunn.ch>, Jakub Kicinski <kuba@kernel.org>,
        Rob Herring <robh+dt@kernel.org>,
        Andreas =?iso-8859-1?Q?F=E4rber?= <afaerber@suse.de>,
        Manivannan Sadhasivam <mani@kernel.org>,
        Philipp Zabel <p.zabel@pengutronix.de>, netdev@vger.kernel.org,
        devicetree@vger.kernel.org, linux-arm-kernel@lists.infradead.org,
        linux-actions@lists.infradead.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH v3 2/3] net: ethernet: actions: Add Actions Semi Owl
 Ethernet MAC driver
Message-ID: <20210322084420.GA1503756@BV030612LT>
References: <cover.1616368101.git.cristian.ciocaltea@gmail.com>
 <ab25bd143589d3c1894cdb3189670efa62ed1440.1616368101.git.cristian.ciocaltea@gmail.com>
 <17876c6e-4688-59e6-216f-445f91a8b884@gmail.com>
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Hi Florian,

On Sun, Mar 21, 2021 at 08:30:07PM -0700, Florian Fainelli wrote:
> Hi Christian,
> 
> On 3/21/2021 4:29 PM, Cristian Ciocaltea wrote:
> > Add new driver for the Ethernet MAC used on the Actions Semi Owl
> > family of SoCs.
> > 
> > Currently this has been tested only on the Actions Semi S500 SoC
> > variant.
> > 
> > Signed-off-by: Cristian Ciocaltea <cristian.ciocaltea@gmail.com>
> 
> [snip]
> 
> Do you know the story behind this Ethernet controller? 

I just happened to get a board based on the S500 SoC, so I took this
opportunity to help improving the mainline kernel support, but other
than that I do not really know much about the hardware history.

> The various
> receive/transmit descriptor definitions are 99% those defined in
> drivers/net/ethernet/stmmicro/stmmac/descs.h for the normal descriptor.

That's an interesting observation. I could only assume the vendor did
not want to reinvent the wheel here, but I cannot say if this is a
common design scheme or is something specific to STMicroelectronics
only.

> The register layout of the MAC looks completely different from a
> dwmac100 or dwmac1000 however.

Most probably this is Actions specific.. 

> -- 
> Florian