target/linux/generic/backport-5.15/769-v5.19-05-net-dsa-qca8k-correctly-handle-mdio-read-error.patch

   1 From 6cfc03b602200c5cbbd8d906fd905547814e83df Mon Sep 17 00:00:00 2001
   2 From: Ansuel Smith <ansuelsmth@gmail.com>
   3 Date: Sat, 16 Apr 2022 01:30:16 +0200
   4 Subject: [PATCH 5/6] net: dsa: qca8k: correctly handle mdio read error
   5
   6 Restore original way to handle mdio read error by returning 0xffff.
   7 This was wrongly changed when the internal_mdio_read was introduced,
   8 now that both legacy and internal use the same function, make sure that
   9 they behave the same way.
  10
  11 Fixes: ce062a0adbfe ("net: dsa: qca8k: fix kernel panic with legacy mdio mapping")
  12 Signed-off-by: Ansuel Smith <ansuelsmth@gmail.com>
  13 Signed-off-by: David S. Miller <davem@davemloft.net>
  14 ---
  15  drivers/net/dsa/qca8k.c | 7 ++++++-
  16  1 file changed, 6 insertions(+), 1 deletion(-)
  17
  18 --- a/drivers/net/dsa/qca8k.c
  19 +++ b/drivers/net/dsa/qca8k.c
  20 @@ -1287,7 +1287,12 @@ qca8k_internal_mdio_read(struct mii_bus
  21         if (ret >= 0)
  22                 return ret;
  23
  24 -       return qca8k_mdio_read(priv, phy, regnum);
  25 +       ret = qca8k_mdio_read(priv, phy, regnum);
  26 +
  27 +       if (ret < 0)
  28 +               return 0xffff;
  29 +
  30 +       return ret;
  31  }
  32
  33  static int