target/linux/generic/backport-5.10/731-net-phy-at803x-fix-probe-error-if-copper-page-is-sel.patch

   1 From 8f7e876273e294b732b42af2e5e6bba91d798954 Mon Sep 17 00:00:00 2001
   2 From: Michael Walle <michael@walle.cc>
   3 Date: Tue, 20 Apr 2021 12:29:29 +0200
   4 Subject: [PATCH] net: phy: at803x: fix probe error if copper page is selected
   5
   6 The commit c329e5afb42f ("net: phy: at803x: select correct page on
   7 config init") selects the copper page during probe. This fails if the
   8 copper page was already selected. In this case, the value of the copper
   9 page (which is 1) is propagated through phy_restore_page() and is
  10 finally returned for at803x_probe(). Fix it, by just using the
  11 at803x_page_write() directly.
  12
  13 Also in case of an error, the regulator is not disabled and leads to a
  14 WARN_ON() when the probe fails. This couldn't happen before, because
  15 at803x_parse_dt() was the last call in at803x_probe(). It is hard to
  16 see, that the parse_dt() actually enables the regulator. Thus move the
  17 regulator_enable() to the probe function and undo it in case of an
  18 error.
  19
  20 Fixes: c329e5afb42f ("net: phy: at803x: select correct page on config init")
  21 Signed-off-by: Michael Walle <michael@walle.cc>
  22 Reviewed-by: David Bauer <mail@david-bauer.net>
  23 Signed-off-by: David S. Miller <davem@davemloft.net>
  24 ---
  25  drivers/net/phy/at803x.c | 23 +++++++++++++++++------
  26  1 file changed, 17 insertions(+), 6 deletions(-)
  27
  28 --- a/drivers/net/phy/at803x.c
  29 +++ b/drivers/net/phy/at803x.c
  30 @@ -527,10 +527,6 @@ static int at803x_parse_dt(struct phy_de
  31                         phydev_err(phydev, "failed to get VDDIO regulator\n");
  32                         return PTR_ERR(priv->vddio);
  33                 }
  34 -
  35 -               ret = regulator_enable(priv->vddio);
  36 -               if (ret < 0)
  37 -                       return ret;
  38         }
  39
  40         return 0;
  41 @@ -552,15 +548,30 @@ static int at803x_probe(struct phy_devic
  42         if (ret)
  43                 return ret;
  44
  45 +       if (priv->vddio) {
  46 +               ret = regulator_enable(priv->vddio);
  47 +               if (ret < 0)
  48 +                       return ret;
  49 +       }
  50 +
  51         /* Some bootloaders leave the fiber page selected.
  52          * Switch to the copper page, as otherwise we read
  53          * the PHY capabilities from the fiber side.
  54          */
  55         if (at803x_match_phy_id(phydev, ATH8031_PHY_ID)) {
  56 -               ret = phy_select_page(phydev, AT803X_PAGE_COPPER);
  57 -               ret = phy_restore_page(phydev, AT803X_PAGE_COPPER, ret);
  58 +               phy_lock_mdio_bus(phydev);
  59 +               ret = at803x_write_page(phydev, AT803X_PAGE_COPPER);
  60 +               phy_unlock_mdio_bus(phydev);
  61 +               if (ret)
  62 +                       goto err;
  63         }
  64
  65 +       return 0;
  66 +
  67 +err:
  68 +       if (priv->vddio)
  69 +               regulator_disable(priv->vddio);
  70 +
  71         return ret;
  72  }
  73