1 files changed, 15 insertions, 7 deletions

diff --git a/drivers/net/ethernet/intel/i40e/i40e_ethtool.c b/drivers/net/ethernet/intel/i40e/i40e_ethtool.c
index 5ca63c5d36b4..5ee27358922a 100644
--- a/drivers/net/ethernet/intel/i40e/i40e_ethtool.c
+++ b/drivers/net/ethernet/intel/i40e/i40e_ethtool.c
@@ -4406,6 +4406,8 @@ static int i40e_set_priv_flags(struct net_device *dev, u32 flags)
         }
 
 flags_complete:
+        changed_flags = orig_flags ^ new_flags;
+
         /* Before we finalize any flag changes, we need to perform some
          * checks to ensure that the changes are supported and safe.
          */
@@ -4415,13 +4417,17 @@ flags_complete:
             !(pf->hw_features & I40E_HW_ATR_EVICT_CAPABLE))
                 return -EOPNOTSUPP;
 
-        /* Disable FW LLDP not supported if NPAR active or if FW
-         * API version < 1.7
+        /* If the driver detected FW LLDP was disabled on init, this flag could
+         * be set, however we do not support _changing_ the flag if NPAR is
+         * enabled or FW API version < 1.7.  There are situations where older
+         * FW versions/NPAR enabled PFs could disable LLDP, however we _must_
+         * not allow the user to enable/disable LLDP with this flag on
+         * unsupported FW versions.
          */
-        if (new_flags & I40E_FLAG_DISABLE_FW_LLDP) {
+        if (changed_flags & I40E_FLAG_DISABLE_FW_LLDP) {
                 if (pf->hw.func_caps.npar_enable) {
                         dev_warn(&pf->pdev->dev,
-                                 "Unable to stop FW LLDP if NPAR active\n");
+                                 "Unable to change FW LLDP if NPAR active\n");
                         return -EOPNOTSUPP;
                 }
 
@@ -4429,7 +4435,7 @@ flags_complete:
                     (pf->hw.aq.api_maj_ver == 1 &&
                      pf->hw.aq.api_min_ver < 7)) {
                         dev_warn(&pf->pdev->dev,
-                                 "FW ver does not support stopping FW LLDP\n");
+                                 "FW ver does not support changing FW LLDP\n");
                         return -EOPNOTSUPP;
                 }
         }
@@ -4439,6 +4445,10 @@ flags_complete:
          * something else has modified the flags variable since we copied it
          * originally. We'll just punt with an error and log something in the
          * message buffer.
+         *
+         * This is the point of no return for this function.  We need to have
+         * checked any discrepancies or misconfigurations and returned
+         * EOPNOTSUPP before updating pf->flags here.
          */
         if (cmpxchg64(&pf->flags, orig_flags, new_flags) != orig_flags) {
                 dev_warn(&pf->pdev->dev,
@@ -4446,8 +4456,6 @@ flags_complete:
                 return -EAGAIN;
         }
 
-        changed_flags = orig_flags ^ new_flags;
-
         /* Process any additional changes needed as a result of flag changes.
          * The changed_flags value reflects the list of bits that were
          * changed in the code above.