target/linux/generic/pending-5.4/751-net-phylink-make-Broadcom-BCM84881-based-SFPs-work.patch

   1 From 7adb5b2126bc013f0964ddaefad6ad1b132e86c3 Mon Sep 17 00:00:00 2001
   2 From: Russell King <rmk+kernel@armlinux.org.uk>
   3 Date: Wed, 11 Dec 2019 10:56:50 +0000
   4 Subject: [PATCH] net: phylink: make Broadcom BCM84881 based SFPs work
   5
   6 The Broadcom BCM84881 does not appear to send the SGMII control word
   7 when operating in SGMII mode, which causes network adapters to fail
   8 to link with the PHY, or decide to operate at fixed 1G speed, even if
   9 the PHY negotiated 100M.
  10
  11 Work around this by detecting the Broadcom BCM84881 and switch to phy
  12 mode rather than inband mode.
  13
  14 Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
  15 Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
  16 Signed-off-by: David S. Miller <davem@davemloft.net>
  17 ---
  18  drivers/net/phy/phylink.c | 18 ++++++++++++++++--
  19  1 file changed, 16 insertions(+), 2 deletions(-)
  20
  21 --- a/drivers/net/phy/phylink.c
  22 +++ b/drivers/net/phy/phylink.c
  23 @@ -1842,10 +1842,20 @@ static void phylink_sfp_link_up(void *up
  24         phylink_run_resolve(pl);
  25  }
  26
  27 +/* The Broadcom BCM84881 in the Methode DM7052 is unable to provide a SGMII
  28 + * or 802.3z control word, so inband will not work.
  29 + */
  30 +static bool phylink_phy_no_inband(struct phy_device *phy)
  31 +{
  32 +       return phy->is_c45 &&
  33 +               (phy->c45_ids.device_ids[1] & 0xfffffff0) == 0xae025150;
  34 +}
  35 +
  36  static int phylink_sfp_connect_phy(void *upstream, struct phy_device *phy)
  37  {
  38         struct phylink *pl = upstream;
  39         phy_interface_t interface;
  40 +       u8 mode;
  41         int ret;
  42
  43         /*
  44 @@ -1857,9 +1867,13 @@ static int phylink_sfp_connect_phy(void
  45          */
  46         phy_support_asym_pause(phy);
  47
  48 +       if (phylink_phy_no_inband(phy))
  49 +               mode = MLO_AN_PHY;
  50 +       else
  51 +               mode = MLO_AN_INBAND;
  52 +
  53         /* Do the initial configuration */
  54 -       ret = phylink_sfp_config(pl, MLO_AN_INBAND, phy->supported,
  55 -                                phy->advertising);
  56 +       ret = phylink_sfp_config(pl, mode, phy->supported, phy->advertising);
  57         if (ret < 0)
  58                 return ret;
  59