[PATCH 6.1 0546/1146] net: amd-xgbe: Fix logic around active and passive cables

Greg Kroah-Hartman
2022-12-28T16:10:46Z

From: Tom Lendacky <thomas.lendacky@amd.com>

[ Upstream commit 4998006c73afe44e2f639d55bd331c6c26eb039f ]

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@amd.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
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)
--
2.35.1