Re: [PATCH net v2] net: phylink: treat PSGMII as an inband capable interface

[Andrew Lunn]

On Sat, Aug 08, 2026 at 07:39:55AM +0530, Sandeep Sondagar wrote:
> PSGMII (the Qualcomm 5-port SGMII) conveys the link negotiation result
> from the PHY back to the MAC through per-channel in-band SGMII words,
> exactly like SGMII and QSGMII.
> 
> However, PHY_INTERFACE_MODE_PSGMII is missing from
> phylink_get_inband_type(), so phylink reports INBAND_NONE for it and
> phylink_pcs_neg_mode() falls back to PHYLINK_PCS_NEG_NONE. The PCS is
> then programmed in force mode and its control-register speed bits (which
> default to 1000base) are used, so a slower copper link - e.g. 100base-T
> - is reported as 1Gbps and cannot pass traffic.
> 
> Classify PSGMII alongside SGMII and QSGMII as INBAND_CISCO_SGMII so the
> PCS negotiates in-band and the resolved link speed comes from the PHY
> in-band word.
> 
> Fixes: 83b5f0253b1e ("net: phy: Introduce PSGMII PHY interface mode")
> Signed-off-by: Sandeep Sondagar <sandeepsondagar@xxxxxxxxx>

Reviewed-by: Andrew Lunn <andrew@xxxxxxx>

    Andrew