i40e: stop using cmpxchg flow in i40e_set_priv_flags()

Now that the only places which modify flags are either (a) during
initialization prior to creating a netdevice, or (b) while holding the
rtnl lock, we no longer need the cmpxchg64 call in i40e_set_priv_flags.

Signed-off-by: Jacob Keller <jacob.e.keller@intel.com>
Tested-by: Andrew Bowers <andrewx.bowers@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>

diff --git a/drivers/net/ethernet/intel/i40e/i40e_ethtool.c b/drivers/net/ethernet/intel/i40e/i40e_ethtool.c
index 2a9c930..b974482 100644 (file)
--- a/drivers/net/ethernet/intel/i40e/i40e_ethtool.c
+++ b/drivers/net/ethernet/intel/i40e/i40e_ethtool.c
@@ -4436,21 +4436,12 @@ flags_complete:
                }
        }
 
-       /* Compare and exchange the new flags into place. If we failed, that
-        * is if cmpxchg returns anything but the old value, this means that
-        * 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.
+       /* Now that we've checked to ensure that the new flags are valid, load
+        * them into place. Since we only modify flags either (a) during
+        * initialization or (b) while holding the RTNL lock, we don't need
+        * anything fancy here.
         */
-       if (cmpxchg64(&pf->flags, orig_flags, new_flags) != orig_flags) {
-               dev_warn(&pf->pdev->dev,
-                        "Unable to update pf->flags as it was modified by another thread...\n");
-               return -EAGAIN;
-       }
+       pf->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