Hi Landen, Andrew,

On Tue, 10 Dec 2019 at 18:36, Andrew Lunn [off-list ref] wrote:

On Tue, Dec 10, 2019 at 04:14:40PM +0800, Landen Chao wrote:

quoted

Add new support for MT7531:

MT7531 is the next generation of MT7530. It is also a 7-ports switch with
5 giga embedded phys, 2 cpu ports, and the same MAC logic of MT7530. Cpu
port 6 only supports HSGMII interface. Cpu port 5 supports either RGMII
or HSGMII in different HW sku.

Hi Landen

Looking at the code, you seem to treat HSGMII as 2500Base-X. Is this
correct? Or is it SGMII over clocked to 2.5Gbps?

         Andrew

I think the better question is: what is being understood by HSGMII?
What does the AN base page look like? Do you support AN with the 2500
baud speed? Do you support AN with lower speeds? Do you support lower
speeds at all? What PHYs do you interoperate with in this mode? If you
don't support AN, then what's so SGMII about it? And for that matter,
if you don't support AN, what's so 2500Base-X (802.3z) about it? I see
you unconditionally force the speed and disable AN in this mode. Do
you have any reference for what SerDes protocol your hardware
implements in this mode?

Thanks,
-Vladimir