The FCLF8521P2BTL is marketed as a drop in replacement for fiber modules using 1000Base-X autoneg towards the host as default. See the referenced application note, esp. question #11. Drop the 1000baseT capability, so 1000Base-X will eventually be used. This is esp. important if the TX_DISABLE pin is not connected on a board. Usually, pin is used as a reset line to the PHY on the copper SFP. If a bootloader expects the default mode and doesn't do any reconfiguration of the SFP module, a link might not be established. Link: https://www.coherent.com/resources/application-note/networking/1000base-t-sfp-faq-an-2036.pdf Signed-off-by: Michael Walle --- I'm not sure, this is the correct place for the fix, nor if it goes in the right direction. There is a comment in /* * Clause 22 copper SFP modules normally operate in Cisco SGMII mode with * negotiation enabled, but some may be in 1000base-X - which is for the * PHY driver to determine. */ I haven't found any traces of that though. So any pointers, what flags have to be modified is appreciated (phydev->supported? phydev->possible_interfaces?). I also compared the EEPROMs of both a FCLF-8520-3 and a FCLF-8521-3 (I don't have a FCLF8520P2BTL) and they are the same except for the P/N and the serial number. So they both advertise the same capabilites. Although I'd suspect that the power-on strapping is different and could be read by the PHY driver. --- drivers/net/phy/sfp.c | 14 ++++++++++++++ 1 file changed, 14 insertions(+) diff --git a/drivers/net/phy/sfp.c b/drivers/net/phy/sfp.c index b9d84612ac6f..387753cb5c62 100644 --- a/drivers/net/phy/sfp.c +++ b/drivers/net/phy/sfp.c @@ -478,6 +478,16 @@ static void sfp_quirk_2500basex(const struct sfp_eeprom_id *id, __set_bit(PHY_INTERFACE_MODE_2500BASEX, caps->interfaces); } +static void sfp_quirk_no_sgmii(const struct sfp_eeprom_id *id, + struct sfp_module_caps *caps) +{ + linkmode_clear_bit(ETHTOOL_LINK_MODE_1000baseT_Half_BIT, + caps->link_modes); + linkmode_clear_bit(ETHTOOL_LINK_MODE_1000baseT_Full_BIT, + caps->link_modes); + __clear_bit(PHY_INTERFACE_MODE_SGMII, caps->interfaces); +} + static void sfp_quirk_disable_autoneg(const struct sfp_eeprom_id *id, struct sfp_module_caps *caps) { @@ -539,6 +549,10 @@ static const struct sfp_quirk sfp_quirks[] = { // PHY. SFP_QUIRK_F("FS", "SFP-10G-T", sfp_fixup_fs_10gt), + // These are sold as 1000base-X compatible. Thus, make sure we don't + // use SGMII. + SFP_QUIRK_S("FINISAR CORP.", "FCLF8521P2BTL", sfp_quirk_no_sgmii), + // Fiberstore SFP-2.5G-T and SFP-10GM-T uses Rollball protocol to talk // to the PHY and needs 4 sec wait before probing the PHY. SFP_QUIRK_F("FS", "SFP-2.5G-T", sfp_fixup_rollball_wait4s), -- 2.47.3