Re: [PATCH 06/16] net: phy: adin: support PHY mode converters

Andrew Lunn
2019-08-05T14:51:12Z

On Mon, Aug 05, 2019 at 07:54:43PM +0300, Alexandru Ardelean wrote:
> Sometimes, the connection between a MAC and PHY is done via a
> mode/interface converter. An example is a GMII-to-RGMII converter, which
> would mean that the MAC operates in GMII mode while the PHY operates in
> RGMII. In this case there is a discrepancy between what the MAC expects &
> what the PHY expects and both need to be configured in their respective
> modes.
>
> Sometimes, this converter is specified via a board/system configuration (in
> the device-tree for example). But, other times it can be left unspecified.
> The use of these converters is common in boards that have FPGA on them.
>
> This patch also adds support for a `adi,phy-mode-internal` property that
> can be used in these (implicit convert) cases. The internal PHY mode will
> be used to specify the correct register settings for the PHY.
>
> `fwnode_handle` is used, since this property may be specified via ACPI as
> well in other setups, but testing has been done in DT context.

Looking at the patch, you seems to assume phy-mode is what the MAC is
using? That seems rather odd, given the name. It seems like a better
solution would be to add a mac-mode, which the MAC uses to configure
its side of the link. The MAC driver would then implement this
property.

I don't see a need for this. phy-mode indicates what the PHY should
use. End of story.

Andrew