From 9956d0504f0bf4f3ef274b30334a4a3833b514b3 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 b8ac07be6157..e7e805a15263 100644 --- a/drivers/net/ethernet/realtek/r8169_main.c +++ b/drivers/net/ethernet/realtek/r8169_main.c @@ -5138,6 +5138,15 @@ 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;