On Fri, Jul 29, 2022 at 05:33:53PM +0200, Maxime Chevallier wrote:
> The QUSGMII mode is a derivative of Cisco's USXGMII standard. This
> standard is pretty similar to SGMII, but allows for faster speeds, and
> has the build-in bits for Quad and Octa variants (like QSGMII).
>
> The main difference with SGMII/QSGMII is that USXGMII/QUSGMII re-uses
> the preamble to carry various information, named 'Extensions'.
>
> As of today, the USXGMII standard only mentions the "PCH" extension,
> which is used to convey timestamps, allowing in-band signaling of PTP
> timestamps without having to modify the frame itself.
>
> This commit adds support for that mode. When no extension is in use, it
> behaves exactly like QSGMII, although it's not compatible with QSGMII.
>
> Signed-off-by: Maxime Chevallier <maxime.chevallier@xxxxxxxxxxx>
Reviewed-by: Andrew Lunn <andrew@xxxxxxx>
Andrew
