Re: [PATCH v3 2/3] net: ethernet: actions: Add Actions Semi Owl Ethernet MAC driver

[Cristian Ciocaltea <cristian.ciocaltea@gmail.com>]

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