From ff7a4adbd7c69653cfb22ec95171a47164ad1603 Mon Sep 17 00:00:00 2001 From: Heiner Kallweit Date: Sat, 30 Mar 2024 12:49:02 +0100 Subject: [PATCH] r8169: fix issue caused by buggy BIOS on certain boards with RTL8168d commit 5d872c9f46bd2ea3524af3c2420a364a13667135 upstream. On some boards with this chip version the BIOS is buggy and misses to reset the PHY page selector. This results in the PHY ID read accessing registers on a different page, returning a more or less random value. Fix this by resetting the page selector first. Fixes: f1e911d5d0df ("r8169: add basic phylib support") Cc: stable@vger.kernel.org Signed-off-by: Heiner Kallweit Reviewed-by: Simon Horman Link: https://lore.kernel.org/r/64f2055e-98b8-45ec-8568-665e3d54d4e6@gmail.com Signed-off-by: Jakub Kicinski Signed-off-by: Greg Kroah-Hartman --- drivers/net/ethernet/realtek/r8169_main.c | 9 +++++++++ 1 file changed, 9 insertions(+) diff --git a/drivers/net/ethernet/realtek/r8169_main.c b/drivers/net/ethernet/realtek/r8169_main.c index e000cabf65f8..319f8d7a502d 100644 --- a/drivers/net/ethernet/realtek/r8169_main.c +++ b/drivers/net/ethernet/realtek/r8169_main.c @@ -6851,6 +6851,15 @@ static int r8169_mdio_register(struct rtl8169_private *tp) struct mii_bus *new_bus; int ret; + /* On some boards with this chip version the BIOS is buggy and misses + * to reset the PHY page selector. This results in the PHY ID read + * accessing registers on a different page, returning a more or + * less random value. Fix this by resetting the page selector first. + */ + if (tp->mac_version == RTL_GIGA_MAC_VER_25 || + tp->mac_version == RTL_GIGA_MAC_VER_26) + r8169_mdio_write(tp, 0x1f, 0); + new_bus = devm_mdiobus_alloc(&pdev->dev); if (!new_bus) return -ENOMEM;