target/linux/generic/backport-5.10/735-v5.14-04-net-dsa-qca8k-handle-qca8k_set_page-errors.patch

   1 From ba5707ec58cfb6853dff41c2aae72deb6a03d389 Mon Sep 17 00:00:00 2001
   2 From: Ansuel Smith <ansuelsmth@gmail.com>
   3 Date: Fri, 14 May 2021 22:59:54 +0200
   4 Subject: [PATCH] net: dsa: qca8k: handle qca8k_set_page errors
   5
   6 With a remote possibility, the set_page function can fail. Since this is
   7 a critical part of the write/read qca8k regs, propagate the error and
   8 terminate any read/write operation.
   9
  10 Signed-off-by: Ansuel Smith <ansuelsmth@gmail.com>
  11 Reviewed-by: Andrew Lunn <andrew@lunn.ch>
  12 Signed-off-by: David S. Miller <davem@davemloft.net>
  13 ---
  14  drivers/net/dsa/qca8k.c | 33 ++++++++++++++++++++++++++-------
  15  1 file changed, 26 insertions(+), 7 deletions(-)
  16
  17 --- a/drivers/net/dsa/qca8k.c
  18 +++ b/drivers/net/dsa/qca8k.c
  19 @@ -127,16 +127,23 @@ qca8k_mii_write32(struct mii_bus *bus, i
  20                                     "failed to write qca8k 32bit register\n");
  21  }
  22
  23 -static void
  24 +static int
  25  qca8k_set_page(struct mii_bus *bus, u16 page)
  26  {
  27 +       int ret;
  28 +
  29         if (page == qca8k_current_page)
  30 -               return;
  31 +               return 0;
  32
  33 -       if (bus->write(bus, 0x18, 0, page) < 0)
  34 +       ret = bus->write(bus, 0x18, 0, page);
  35 +       if (ret < 0) {
  36                 dev_err_ratelimited(&bus->dev,
  37                                     "failed to set qca8k page\n");
  38 +               return ret;
  39 +       }
  40 +
  41         qca8k_current_page = page;
  42 +       return 0;
  43  }
  44
  45  static u32
  46 @@ -150,11 +157,14 @@ qca8k_read(struct qca8k_priv *priv, u32
  47
  48         mutex_lock_nested(&bus->mdio_lock, MDIO_MUTEX_NESTED);
  49
  50 -       qca8k_set_page(bus, page);
  51 +       val = qca8k_set_page(bus, page);
  52 +       if (val < 0)
  53 +               goto exit;
  54 +
  55         val = qca8k_mii_read32(bus, 0x10 | r2, r1);
  56
  57 +exit:
  58         mutex_unlock(&bus->mdio_lock);
  59 -
  60         return val;
  61  }
  62
  63 @@ -163,14 +173,19 @@ qca8k_write(struct qca8k_priv *priv, u32
  64  {
  65         struct mii_bus *bus = priv->bus;
  66         u16 r1, r2, page;
  67 +       int ret;
  68
  69         qca8k_split_addr(reg, &r1, &r2, &page);
  70
  71         mutex_lock_nested(&bus->mdio_lock, MDIO_MUTEX_NESTED);
  72
  73 -       qca8k_set_page(bus, page);
  74 +       ret = qca8k_set_page(bus, page);
  75 +       if (ret < 0)
  76 +               goto exit;
  77 +
  78         qca8k_mii_write32(bus, 0x10 | r2, r1, val);
  79
  80 +exit:
  81         mutex_unlock(&bus->mdio_lock);
  82  }
  83
  84 @@ -185,12 +200,16 @@ qca8k_rmw(struct qca8k_priv *priv, u32 r
  85
  86         mutex_lock_nested(&bus->mdio_lock, MDIO_MUTEX_NESTED);
  87
  88 -       qca8k_set_page(bus, page);
  89 +       ret = qca8k_set_page(bus, page);
  90 +       if (ret < 0)
  91 +               goto exit;
  92 +
  93         ret = qca8k_mii_read32(bus, 0x10 | r2, r1);
  94         ret &= ~mask;
  95         ret |= val;
  96         qca8k_mii_write32(bus, 0x10 | r2, r1, ret);
  97
  98 +exit:
  99         mutex_unlock(&bus->mdio_lock);
 100
 101         return ret;