releases/4.19.312/r8169-fix-issue-caused-by-buggy-bios-on-certain-boards-with-rtl8168d.patch

   1 From 5d872c9f46bd2ea3524af3c2420a364a13667135 Mon Sep 17 00:00:00 2001
   2 From: Heiner Kallweit <hkallweit1@gmail.com>
   3 Date: Sat, 30 Mar 2024 12:49:02 +0100
   4 Subject: r8169: fix issue caused by buggy BIOS on certain boards with RTL8168d
   5
   6 From: Heiner Kallweit <hkallweit1@gmail.com>
   7
   8 commit 5d872c9f46bd2ea3524af3c2420a364a13667135 upstream.
   9
  10 On some boards with this chip version the BIOS is buggy and misses
  11 to reset the PHY page selector. This results in the PHY ID read
  12 accessing registers on a different page, returning a more or
  13 less random value. Fix this by resetting the page selector first.
  14
  15 Fixes: f1e911d5d0df ("r8169: add basic phylib support")
  16 Cc: stable@vger.kernel.org
  17 Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>
  18 Reviewed-by: Simon Horman <horms@kernel.org>
  19 Link: https://lore.kernel.org/r/64f2055e-98b8-45ec-8568-665e3d54d4e6@gmail.com
  20 Signed-off-by: Jakub Kicinski <kuba@kernel.org>
  21 Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
  22 ---
  23  drivers/net/ethernet/realtek/r8169_main.c |    9 +++++++++
  24  1 file changed, 9 insertions(+)
  25
  26 --- a/drivers/net/ethernet/realtek/r8169_main.c
  27 +++ b/drivers/net/ethernet/realtek/r8169_main.c
  28 @@ -7303,6 +7303,15 @@ static int r8169_mdio_register(struct rt
  29         struct mii_bus *new_bus;
  30         int ret;
  31
  32 +       /* On some boards with this chip version the BIOS is buggy and misses
  33 +        * to reset the PHY page selector. This results in the PHY ID read
  34 +        * accessing registers on a different page, returning a more or
  35 +        * less random value. Fix this by resetting the page selector first.
  36 +        */
  37 +       if (tp->mac_version == RTL_GIGA_MAC_VER_25 ||
  38 +           tp->mac_version == RTL_GIGA_MAC_VER_26)
  39 +               r8169_mdio_write(tp, 0x1f, 0);
  40 +
  41         new_bus = devm_mdiobus_alloc(&pdev->dev);
  42         if (!new_bus)
  43                 return -ENOMEM;