[PATCH v2 7/8] net: mvmdio: add xmdio support

[antoine.tenart@free-electrons.com (Antoine Tenart)]

Hello Florian, Andrew,

On Thu, Jun 08, 2017 at 06:55:46PM +0200, Andrew Lunn wrote:
> On Thu, Jun 08, 2017 at 09:42:21AM -0700, Florian Fainelli wrote:
> > On 06/08/2017 02:26 AM, Antoine Tenart wrote:
> > > This patch adds the xMDIO interface support in the mvmdio driver. This
> > > interface is used in Ethernet controllers on Marvell 370, 7k and 8k (as
> > > of now). The xSMI interface supported by this driver complies with the
> > > IEEE 802.3 clause 45 (while the SMI interface complies with the clause
> > > 22). The xSMI interface is used by 10GbE devices.
> > 
> > In the previous version you were properly defining a new compatibles
> > strings for xmdio, but now you don't and instead you runtime select the
> > operations based on whether MII_ADDR_C45 is set in the register which is
> > fine from a functional perspective.
> > 
> > If I get this right, the xMDIO controller is actually a superset of the
> > MDIO controller and has an extra MVMDIO_XSMI_ADDR_REG register to
> > preform C45 accesses?
> > 
> > If that is the case (and looking at patch 8 that seems to be the case),
> > you probably still need to define a new compatible string for that
> > block, because it has a different register layout than its predecessor.
> 
> Yes, i think you need the compatible string to return -EOPNOSUP when
> somebody tries to do a C45 access on the older IP which only has C22.

That's a very good point. I'll update the series to fix this.

Thanks!
Antoine

-- 
Antoine T?nart, Free Electrons
Embedded Linux and Kernel engineering
http://free-electrons.com
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