[PATCH net] ixgbe: fix X550 AQ PHY identification returning ixgbe_phy_unknown

[Aleksandr Loktionov <aleksandr.loktionov@intel.com>]

ixgbe_get_phy_id() reads the two MII_PHYSID registers and combines them
into hw->phy.id with the lower 4 revision bits masked out by
IXGBE_PHY_REVISION_MASK (0xFFFFFFF0).

Commit 5f1c3589b0f0 ("ixgbe: Correct X550 phy ID") replaced
X550_PHY_ID (0x01540220) with X550_PHY_ID2 (0x01540223) and
X550_PHY_ID3 (0x01540221).  These are the raw values read directly off
hardware, but after revision-bit masking both reduce to 0x01540220.
The switch cases in ixgbe_get_phy_type_from_id() therefore never match,
and X550 AQ PHY devices always fall through to ixgbe_phy_unknown.  A
wrong PHY type means the wrong ops vector is selected, resulting in
failed PHY initialization and no link.

Restore X550_PHY_ID (0x01540220) as the match value -- the
revision-stripped ID that the driver actually stores.  Keep X550_PHY_ID2
and X550_PHY_ID3 as documentation of the hardware-reported values.

Fixes: 5f1c3589b0f0 ("ixgbe: Correct X550 phy ID")
Signed-off-by: Aleksandr Loktionov <aleksandr.loktionov@intel.com>
---
 drivers/net/ethernet/intel/ixgbe/ixgbe_phy.c  | 3 +--
 drivers/net/ethernet/intel/ixgbe/ixgbe_type.h | 1 +
 2 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/net/ethernet/intel/ixgbe/ixgbe_phy.c b/drivers/net/ethernet/intel/ixgbe/ixgbe_phy.c
index ab733e7..ca98dad 100644
--- a/drivers/net/ethernet/intel/ixgbe/ixgbe_phy.c
+++ b/drivers/net/ethernet/intel/ixgbe/ixgbe_phy.c
@@ -364,8 +364,7 @@ static enum ixgbe_phy_type ixgbe_get_phy_type_from_id(u32 phy_id)
 	case TN1010_PHY_ID:
 		phy_type = ixgbe_phy_tn;
 		break;
-	case X550_PHY_ID2:
-	case X550_PHY_ID3:
+	case X550_PHY_ID:
 	case X540_PHY_ID:
 		phy_type = ixgbe_phy_aq;
 		break;
diff --git a/drivers/net/ethernet/intel/ixgbe/ixgbe_type.h b/drivers/net/ethernet/intel/ixgbe/ixgbe_type.h
index 61f2ef6..0d47622 100644
--- a/drivers/net/ethernet/intel/ixgbe/ixgbe_type.h
+++ b/drivers/net/ethernet/intel/ixgbe/ixgbe_type.h
@@ -1412,6 +1412,7 @@ struct ixgbe_nvm_version {
 #define TN1010_PHY_ID    0x00A19410
 #define TNX_FW_REV       0xB
 #define X540_PHY_ID      0x01540200
+#define X550_PHY_ID      0x01540220
 #define X550_PHY_ID2	0x01540223
 #define X550_PHY_ID3	0x01540221
 #define X557_PHY_ID      0x01540240
-- 
2.52.0