[PATCH net 1/2] net: amd-xgbe: Fix logic around active and passive cables

[Tom Lendacky]

SFP+ active and passive cables are copper cables with fixed SFP+ end
connectors. Due to a misinterpretation of this, SFP+ active cables could
end up not being recognized, causing the driver to fail to establish a
connection.

Introduce a new enum in SFP+ cable types, XGBE_SFP_CABLE_FIBER, that is
the default cable type, and handle active and passive cables when they are
specifically detected.

Fixes: abf0a1c2b26a ("amd-xgbe: Add support for SFP+ modules")
Signed-off-by: Tom Lendacky <thomas.lendacky@xxxxxxx>
---
 drivers/net/ethernet/amd/xgbe/xgbe-phy-v2.c | 9 ++++++---
 1 file changed, 6 insertions(+), 3 deletions(-)

diff --git a/drivers/net/ethernet/amd/xgbe/xgbe-phy-v2.c b/drivers/net/ethernet/amd/xgbe/xgbe-phy-v2.c
index 4064c3e3dd49..868a768f424c 100644
--- a/drivers/net/ethernet/amd/xgbe/xgbe-phy-v2.c
+++ b/drivers/net/ethernet/amd/xgbe/xgbe-phy-v2.c
@@ -189,6 +189,7 @@ enum xgbe_sfp_cable {
 	XGBE_SFP_CABLE_UNKNOWN = 0,
 	XGBE_SFP_CABLE_ACTIVE,
 	XGBE_SFP_CABLE_PASSIVE,
+	XGBE_SFP_CABLE_FIBER,
 };
 
 enum xgbe_sfp_base {
@@ -1149,16 +1150,18 @@ static void xgbe_phy_sfp_parse_eeprom(struct xgbe_prv_data *pdata)
 	phy_data->sfp_tx_fault = xgbe_phy_check_sfp_tx_fault(phy_data);
 	phy_data->sfp_rx_los = xgbe_phy_check_sfp_rx_los(phy_data);
 
-	/* Assume ACTIVE cable unless told it is PASSIVE */
+	/* Assume FIBER cable unless told otherwise */
 	if (sfp_base[XGBE_SFP_BASE_CABLE] & XGBE_SFP_BASE_CABLE_PASSIVE) {
 		phy_data->sfp_cable = XGBE_SFP_CABLE_PASSIVE;
 		phy_data->sfp_cable_len = sfp_base[XGBE_SFP_BASE_CU_CABLE_LEN];
-	} else {
+	} else if (sfp_base[XGBE_SFP_BASE_CABLE] & XGBE_SFP_BASE_CABLE_ACTIVE) {
 		phy_data->sfp_cable = XGBE_SFP_CABLE_ACTIVE;
+	} else {
+		phy_data->sfp_cable = XGBE_SFP_CABLE_FIBER;
 	}
 
 	/* Determine the type of SFP */
-	if (phy_data->sfp_cable == XGBE_SFP_CABLE_PASSIVE &&
+	if (phy_data->sfp_cable != XGBE_SFP_CABLE_FIBER &&
 	    xgbe_phy_sfp_bit_rate(sfp_eeprom, XGBE_SFP_SPEED_10000))
 		phy_data->sfp_base = XGBE_SFP_BASE_10000_CR;
 	else if (sfp_base[XGBE_SFP_BASE_10GBE_CC] & XGBE_SFP_BASE_10GBE_CC_SR)
-- 
2.38.1