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

[Simon Horman <horms@kernel.org>]

On Thu, Apr 30, 2026 at 02:31:53PM +0200, Aleksandr Loktionov wrote:
> 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>

Reviewed-by: Simon Horman <horms@kernel.org>