net/mlx5e: Don't override netdev features field unless in error flow

Set features function sets dev->features in order to keep track of which
features were successfully changed and which weren't (in case the user
asks for more than one change in a single command).

This breaks the logic in __netdev_update_features which assumes that
dev->features is not changed on success and checks for diffs between
features and dev->features (diffs that might not exist at this point
because of the driver override).

The solution is to keep track of successful/failed feature changes and
assign them to dev->features in case of failure only.

Fixes: 0e405443e803 ("net/mlx5e: Improve set features ndo resiliency")
Signed-off-by: Gal Pressman <galp@mellanox.com>
Signed-off-by: Saeed Mahameed <saeedm@mellanox.com>

1 files changed, 25 insertions, 18 deletions

diff --git a/drivers/net/ethernet/mellanox/mlx5/core/en_main.c b/drivers/net/ethernet/mellanox/mlx5/core/en_main.c
index d9d8227f195f..311d5ec8407c 100644
--- a/drivers/net/ethernet/mellanox/mlx5/core/en_main.c
+++ b/drivers/net/ethernet/mellanox/mlx5/core/en_main.c
@@ -3219,12 +3219,12 @@ static int mlx5e_set_mac(struct net_device *netdev, void *addr)
         return 0;
 }
 
-#define MLX5E_SET_FEATURE(netdev, feature, enable)      \
+#define MLX5E_SET_FEATURE(features, feature, enable)    \
         do {                                            \
                 if (enable)                             \
-                        netdev->features |= feature;    \
+                        *features |= feature;           \
                 else                                    \
-                        netdev->features &= ~feature;   \
+                        *features &= ~feature;          \
         } while (0)
 
 typedef int (*mlx5e_feature_handler)(struct net_device *netdev, bool enable);
@@ -3347,6 +3347,7 @@ static int set_feature_arfs(struct net_device *netdev, bool enable)
 #endif
 
 static int mlx5e_handle_feature(struct net_device *netdev,
+                                netdev_features_t *features,
                                 netdev_features_t wanted_features,
                                 netdev_features_t feature,
                                 mlx5e_feature_handler feature_handler)
@@ -3365,34 +3366,40 @@ static int mlx5e_handle_feature(struct net_device *netdev,
                 return err;
         }
 
-        MLX5E_SET_FEATURE(netdev, feature, enable);
+        MLX5E_SET_FEATURE(features, feature, enable);
         return 0;
 }
 
 static int mlx5e_set_features(struct net_device *netdev,
                               netdev_features_t features)
 {
+        netdev_features_t oper_features = netdev->features;
         int err;
 
-        err  = mlx5e_handle_feature(netdev, features, NETIF_F_LRO,
-                                    set_feature_lro);
-        err |= mlx5e_handle_feature(netdev, features,
+        err  = mlx5e_handle_feature(netdev, &oper_features, features,
+                                    NETIF_F_LRO, set_feature_lro);
+        err |= mlx5e_handle_feature(netdev, &oper_features, features,
                                     NETIF_F_HW_VLAN_CTAG_FILTER,
                                     set_feature_cvlan_filter);
-        err |= mlx5e_handle_feature(netdev, features, NETIF_F_HW_TC,
-                                    set_feature_tc_num_filters);
-        err |= mlx5e_handle_feature(netdev, features, NETIF_F_RXALL,
-                                    set_feature_rx_all);
-        err |= mlx5e_handle_feature(netdev, features, NETIF_F_RXFCS,
-                                    set_feature_rx_fcs);
-        err |= mlx5e_handle_feature(netdev, features, NETIF_F_HW_VLAN_CTAG_RX,
-                                    set_feature_rx_vlan);
+        err |= mlx5e_handle_feature(netdev, &oper_features, features,
+                                    NETIF_F_HW_TC, set_feature_tc_num_filters);
+        err |= mlx5e_handle_feature(netdev, &oper_features, features,
+                                    NETIF_F_RXALL, set_feature_rx_all);
+        err |= mlx5e_handle_feature(netdev, &oper_features, features,
+                                    NETIF_F_RXFCS, set_feature_rx_fcs);
+        err |= mlx5e_handle_feature(netdev, &oper_features, features,
+                                    NETIF_F_HW_VLAN_CTAG_RX, set_feature_rx_vlan);
 #ifdef CONFIG_RFS_ACCEL
-        err |= mlx5e_handle_feature(netdev, features, NETIF_F_NTUPLE,
-                                    set_feature_arfs);
+        err |= mlx5e_handle_feature(netdev, &oper_features, features,
+                                    NETIF_F_NTUPLE, set_feature_arfs);
 #endif
 
-        return err ? -EINVAL : 0;
+        if (err) {
+                netdev->features = oper_features;
+                return -EINVAL;
+        }
+
+        return 0;
 }
 
 static netdev_features_t mlx5e_fix_features(struct net_device *netdev,