target/linux/generic/backport-5.10/738-v5.14-01-net-dsa-qca8k-fix-an-endian-bug-in-qca8k-get-ethtool.patch

   1 aFrom aa3d020b22cb844ab7bdbb9e5d861a64666e2b74 Mon Sep 17 00:00:00 2001
   2 From: Dan Carpenter <dan.carpenter@oracle.com>
   3 Date: Wed, 9 Jun 2021 12:52:12 +0300
   4 Subject: [PATCH] net: dsa: qca8k: fix an endian bug in
   5  qca8k_get_ethtool_stats()
   6
   7 The "hi" variable is a u64 but the qca8k_read() writes to the top 32
   8 bits of it.  That will work on little endian systems but it's a bit
   9 subtle.  It's cleaner to make declare "hi" as a u32.  We will still need
  10 to cast it when we shift it later on in the function but that's fine.
  11
  12 Fixes: 7c9896e37807 ("net: dsa: qca8k: check return value of read functions correctly")
  13 Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
  14 Reviewed-by: Vladimir Oltean <olteanv@gmail.com>
  15 Signed-off-by: David S. Miller <davem@davemloft.net>
  16 ---
  17  drivers/net/dsa/qca8k.c | 6 +++---
  18  1 file changed, 3 insertions(+), 3 deletions(-)
  19
  20 --- a/drivers/net/dsa/qca8k.c
  21 +++ b/drivers/net/dsa/qca8k.c
  22 @@ -1412,7 +1412,7 @@ qca8k_get_ethtool_stats(struct dsa_switc
  23         struct qca8k_priv *priv = (struct qca8k_priv *)ds->priv;
  24         const struct qca8k_mib_desc *mib;
  25         u32 reg, i, val;
  26 -       u64 hi = 0;
  27 +       u32 hi = 0;
  28         int ret;
  29
  30         for (i = 0; i < ARRAY_SIZE(ar8327_mib); i++) {
  31 @@ -1424,14 +1424,14 @@ qca8k_get_ethtool_stats(struct dsa_switc
  32                         continue;
  33
  34                 if (mib->size == 2) {
  35 -                       ret = qca8k_read(priv, reg + 4, (u32 *)&hi);
  36 +                       ret = qca8k_read(priv, reg + 4, &hi);
  37                         if (ret < 0)
  38                                 continue;
  39                 }
  40
  41                 data[i] = val;
  42                 if (mib->size == 2)
  43 -                       data[i] |= hi << 32;
  44 +                       data[i] |= (u64)hi << 32;
  45         }
  46  }
  47