From 4e432e530db0056450fbc4a3cee793f16adc39a7 Mon Sep 17 00:00:00 2001 From: Daniel Golle Date: Tue, 8 Oct 2024 23:58:41 +0100 Subject: [PATCH] net: phy: populate host_interfaces when attaching PHY Use bitmask of interfaces supported by the MAC for the PHY to choose from if the declared interface mode is among those using a single pair of SerDes lanes. This will allow 2500Base-T PHYs to switch to SGMII on most hosts, which results in half-duplex being supported in case the MAC supports them. Without this change, 2500Base-T PHYs will always operate in 2500Base-X mode with rate-matching, which is not only wasteful in terms of energy consumption, but also limits the supported interface modes to full-duplex only. Signed-off-by: Daniel Golle --- drivers/net/phy/phylink.c | 21 ++++++++++++++++++++- 1 file changed, 20 insertions(+), 1 deletion(-) --- a/drivers/net/phy/phylink.c +++ b/drivers/net/phy/phylink.c @@ -2017,7 +2017,7 @@ int phylink_fwnode_phy_connect(struct ph { struct fwnode_handle *phy_fwnode; struct phy_device *phy_dev; - int ret; + int i, ret; /* Fixed links and 802.3z are handled without needing a PHY */ if (pl->cfg_link_an_mode == MLO_AN_FIXED || @@ -2044,6 +2044,25 @@ int phylink_fwnode_phy_connect(struct ph pl->link_config.interface = pl->link_interface; } + /* Assume single-lane SerDes interface modes share the same + * lanes and allow the PHY to switch to slower also supported modes + */ + for (i = ARRAY_SIZE(phylink_sfp_interface_preference) - 1; i >= 0; i--) { + /* skip unsupported modes */ + if (!test_bit(phylink_sfp_interface_preference[i], pl->config->supported_interfaces)) + continue; + + __set_bit(phylink_sfp_interface_preference[i], phy_dev->host_interfaces); + + /* skip all faster modes */ + if (phylink_sfp_interface_preference[i] == pl->link_interface) + break; + } + + if (test_bit(pl->link_interface, phylink_sfp_interfaces)) + phy_interface_and(phy_dev->host_interfaces, phylink_sfp_interfaces, + pl->config->supported_interfaces); + ret = phy_attach_direct(pl->netdev, phy_dev, flags, pl->link_interface); phy_device_free(phy_dev);