target/linux/generic/backport-6.6/711-v6.8-01-net-phy-at803x-generalize-cdt-fault-length-function.patch

   1 From 22eb276098da820d9440fad22901f9b74ed4d659 Mon Sep 17 00:00:00 2001
   2 From: Christian Marangi <ansuelsmth@gmail.com>
   3 Date: Thu, 4 Jan 2024 22:30:38 +0100
   4 Subject: [PATCH 1/4] net: phy: at803x: generalize cdt fault length function
   5
   6 Generalize cable test fault length function since they all base on the
   7 same magic values (already reverse engineered to understand the meaning
   8 of it) to have consistenct values on every PHY.
   9
  10 Signed-off-by: Christian Marangi <ansuelsmth@gmail.com>
  11 Reviewed-by: Simon Horman <horms@kernel.org>
  12 Signed-off-by: David S. Miller <davem@davemloft.net>
  13 ---
  14  drivers/net/phy/at803x.c | 13 ++++++-------
  15  1 file changed, 6 insertions(+), 7 deletions(-)
  16
  17 --- a/drivers/net/phy/at803x.c
  18 +++ b/drivers/net/phy/at803x.c
  19 @@ -1192,10 +1192,8 @@ static bool at803x_cdt_fault_length_vali
  20         return false;
  21  }
  22
  23 -static int at803x_cdt_fault_length(u16 status)
  24 +static int at803x_cdt_fault_length(int dt)
  25  {
  26 -       int dt;
  27 -
  28         /* According to the datasheet the distance to the fault is
  29          * DELTA_TIME * 0.824 meters.
  30          *
  31 @@ -1211,8 +1209,6 @@ static int at803x_cdt_fault_length(u16 s
  32          * With a VF of 0.69 we get the factor 0.824 mentioned in the
  33          * datasheet.
  34          */
  35 -       dt = FIELD_GET(AT803X_CDT_STATUS_DELTA_TIME_MASK, status);
  36 -
  37         return (dt * 824) / 10;
  38  }
  39
  40 @@ -1265,9 +1261,11 @@ static int at803x_cable_test_one_pair(st
  41         ethnl_cable_test_result(phydev, ethtool_pair[pair],
  42                                 at803x_cable_test_result_trans(val));
  43
  44 -       if (at803x_cdt_fault_length_valid(val))
  45 +       if (at803x_cdt_fault_length_valid(val)) {
  46 +               val = FIELD_GET(AT803X_CDT_STATUS_DELTA_TIME_MASK, val);
  47                 ethnl_cable_test_fault_length(phydev, ethtool_pair[pair],
  48                                               at803x_cdt_fault_length(val));
  49 +       }
  50
  51         return 1;
  52  }
  53 @@ -1992,7 +1990,8 @@ static int qca808x_cdt_fault_length(stru
  54         if (val < 0)
  55                 return val;
  56
  57 -       return (FIELD_GET(QCA808X_CDT_DIAG_LENGTH, val) * 824) / 10;
  58 +       val = FIELD_GET(QCA808X_CDT_DIAG_LENGTH, val);
  59 +       return at803x_cdt_fault_length(val);
  60  }
  61
  62  static int qca808x_cable_test_start(struct phy_device *phydev)