[PATCH 1/3] net: stmmac: support low-speed USXGMII validation

[Zhangfei Gao <zhangfei.gao@oss.qualcomm.com>]

USXGMII transports the negotiated copper media rate over a fixed-rate
serial link. The PCS and MAC must retain the corresponding
10/100/1000/2500/5000/10000M full-duplex capabilities.

Advertise the media-rate link modes from the XPCS and allow the stmmac
MAC to validate 10M and 100M USXGMII links. This keeps phylink from
rejecting an AQR113C PHY whose advertisement contains base-T modes.

The XPCS also consumes the PHY-generated Clause 37 in-band link and
speed status, so USXGMII must use in-band signalling.

Signed-off-by: Zhangfei Gao <zhangfei.gao@oss.qualcomm.com>
---
 drivers/net/ethernet/stmicro/stmmac/stmmac_main.c | 2 ++
 drivers/net/pcs/pcs-xpcs.c                        | 9 ++++++++-
 2 files changed, 10 insertions(+), 1 deletion(-)

diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
index 2dc0cb2916daf..5954048a9f7fc 100644
--- a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
+++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
@@ -1045,6 +1045,8 @@ static unsigned long stmmac_mac_get_caps(struct phylink_config *config,
 		priv->hw->link.caps &= ~(MAC_1000HD | MAC_100HD | MAC_10HD);
 
 	config->mac_capabilities = priv->hw->link.caps;
+	if (interface == PHY_INTERFACE_MODE_USXGMII)
+		config->mac_capabilities |= MAC_10FD | MAC_100FD;
 
 	if (priv->plat->max_speed)
 		phylink_limit_mac_speed(config, priv->plat->max_speed);
diff --git a/drivers/net/pcs/pcs-xpcs.c b/drivers/net/pcs/pcs-xpcs.c
index 091c9b57388fa..58ca296fc4420 100644
--- a/drivers/net/pcs/pcs-xpcs.c
+++ b/drivers/net/pcs/pcs-xpcs.c
@@ -23,6 +23,12 @@ static const int xpcs_usxgmii_features[] = {
 	ETHTOOL_LINK_MODE_Pause_BIT,
 	ETHTOOL_LINK_MODE_Asym_Pause_BIT,
 	ETHTOOL_LINK_MODE_Autoneg_BIT,
+	ETHTOOL_LINK_MODE_10baseT_Full_BIT,
+	ETHTOOL_LINK_MODE_100baseT_Full_BIT,
+	ETHTOOL_LINK_MODE_1000baseT_Full_BIT,
+	ETHTOOL_LINK_MODE_2500baseT_Full_BIT,
+	ETHTOOL_LINK_MODE_5000baseT_Full_BIT,
+	ETHTOOL_LINK_MODE_10000baseT_Full_BIT,
 	ETHTOOL_LINK_MODE_1000baseKX_Full_BIT,
 	ETHTOOL_LINK_MODE_10000baseKX4_Full_BIT,
 	ETHTOOL_LINK_MODE_10000baseKR_Full_BIT,
@@ -737,7 +743,8 @@ static unsigned int xpcs_inband_caps(struct phylink_pcs *pcs,
 	case DW_10GBASER:
 	case DW_2500BASEX:
 	case DW_AN_C37_USXGMII:
-		return LINK_INBAND_DISABLE;
+		/* The PCS consumes the PHY's CL37 in-band link and speed status. */
+		return LINK_INBAND_ENABLE;
 
 	default:
 		return 0;
-- 
2.43.0