Re: [PATCH net-next v2 13/14] net: stmmac: tc956x: add TC956x/QPS615 support

[Maxime Chevallier <maxime.chevallier@bootlin.com>]

Hi Alex,

On 6/5/26 03:00, Alex Elder wrote:
> From: Daniel Thompson <daniel@riscstar.com>
> 
> Toshiba TC956x is an Ethernet AVB/TSN bridge and is essentially a
> small and highly-specialized SoC. TC956x includes an "eMAC" subsystem
> that can be accessed, along with several other peripherals, via two
> PCIe endpoint functions. There is a main driver for the endpoint that
> decomposes things and creates auxiliary bus devices to model the SoC.
> 
> The eMAC consists of a Designware XGMAC, XPCS and PMA. Each eMAC is
> supported by an MSIGEN that bridges TC956x level interrupts to PCIe
> MSIs.
> 
> Add a driver for the eMAC/MSIGEN combination.
> 
> Co-developed-by: Alex Elder <elder@riscstar.com>
> Signed-off-by: Alex Elder <elder@riscstar.com>
> Signed-off-by: Daniel Thompson <daniel@riscstar.com>
> ---
[...]

> +static int tc956x_lookup_max_speed(phy_interface_t phy_interface)
> +{
> +	switch (phy_interface) {
> +	case PHY_INTERFACE_MODE_SGMII:

The SGMII definition we use in the kernel is the Cisco SGMII de-facto
standard that only supports 10/100/1000M. Some vendors use flavours with
names such as HS-SGMII and such, that's basically SGMII clocked at 2.5G
with aneg disabled. It kinda becomes 2500BaseX then.

So all in all, we don't support 2500M on SGMII.

> +	case PHY_INTERFACE_MODE_2500BASEX:
> +		return SPEED_2500;
> +
> +	default:
> +		return -EOPNOTSUPP;
> +	}

Maxime