The LAN7801 is designed exclusively for external PHYs (unlike the LAN7800/LAN7850 which have internal PHYs), but lan78xx_mdio_init() restricts PHY scanning to MDIO addresses 0-7 by setting phy_mask to ~(0xFF). This prevents discovery of external PHYs wired to addresses outside that range. One such case is the DP83TC814 100BASE-T1 PHY, which is typically configured at MDIO address 10 via PHYAD bootstrap pins and goes undetected with the current mask. Remove the restrictive phy_mask assignment for the LAN7801 so that the default mask of 0 applies, allowing all 32 MDIO addresses to be scanned during bus registration. Fixes: 02dc1f3d613d ("lan78xx: add LAN7801 MAC only support") Signed-off-by: Martin Pålsson --- Changes in v3: - Removed restrictive phy_mask assignment and comment, relying on the default mask of 0 to scan all 32 MDIO addresses (Maxime Chevallier) - Link to v2: https://lore.kernel.org/r/20260216-lan78xx-phy-mask-fix-v2-1-6e97e59edd47@poleshift.se Changes in v2: - Added Fixes: tag - Link to v1: https://lore.kernel.org/r/20260214-lan78xx-phy-mask-fix-v1-1-3baa100861e4@poleshift.se --- drivers/net/usb/lan78xx.c | 2 -- 1 file changed, 2 deletions(-) diff --git a/drivers/net/usb/lan78xx.c b/drivers/net/usb/lan78xx.c index 00397a807393..065588c9cfa6 100644 --- a/drivers/net/usb/lan78xx.c +++ b/drivers/net/usb/lan78xx.c @@ -2094,8 +2094,6 @@ static int lan78xx_mdio_init(struct lan78xx_net *dev) dev->mdiobus->phy_mask = ~(1 << 1); break; case ID_REV_CHIP_ID_7801_: - /* scan thru PHYAD[2..0] */ - dev->mdiobus->phy_mask = ~(0xFF); break; } --- base-commit: ee5492fd88cfc079c19fbeac78e9e53b7f6c04f3 change-id: 20260214-lan78xx-phy-mask-fix-a4260de15a4c Best regards, -- Martin Pålsson