net: dsa: exit probe if no switch were found

If no switch were found in dsa_setup_dst, return -ENODEV and
exit the dsa_probe cleanly.

Signed-off-by: Neil Armstrong <narmstrong@baylibre.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 16 insertions, 3 deletions

diff --git a/net/dsa/dsa.c b/net/dsa/dsa.c
index d5a162cda087..adb5325f4934 100644
--- a/net/dsa/dsa.c
+++ b/net/dsa/dsa.c
@@ -837,10 +837,11 @@ static inline void dsa_of_remove(struct device *dev)
 }
 #endif
 
-static void dsa_setup_dst(struct dsa_switch_tree *dst, struct net_device *dev,
-                          struct device *parent, struct dsa_platform_data *pd)
+static int dsa_setup_dst(struct dsa_switch_tree *dst, struct net_device *dev,
+                         struct device *parent, struct dsa_platform_data *pd)
 {
         int i;
+        unsigned configured = 0;
 
         dst->pd = pd;
         dst->master_netdev = dev;
@@ -860,9 +861,17 @@ static void dsa_setup_dst(struct dsa_switch_tree *dst, struct net_device *dev,
                 dst->ds[i] = ds;
                 if (ds->drv->poll_link != NULL)
                         dst->link_poll_needed = 1;
+
+                ++configured;
         }
 
         /*
+         * If no switch was found, exit cleanly
+         */
+        if (!configured)
+                return -EPROBE_DEFER;
+
+        /*
          * If we use a tagging format that doesn't have an ethertype
          * field, make sure that all packets from this point on get
          * sent to the tag format's receive function.
@@ -878,6 +887,8 @@ static void dsa_setup_dst(struct dsa_switch_tree *dst, struct net_device *dev,
                 dst->link_poll_timer.expires = round_jiffies(jiffies + HZ);
                 add_timer(&dst->link_poll_timer);
         }
+
+        return 0;
 }
 
 static int dsa_probe(struct platform_device *pdev)
@@ -927,7 +938,9 @@ static int dsa_probe(struct platform_device *pdev)
 
         platform_set_drvdata(pdev, dst);
 
-        dsa_setup_dst(dst, dev, &pdev->dev, pd);
+        ret = dsa_setup_dst(dst, dev, &pdev->dev, pd);
+        if (ret)
+                goto out;
 
         return 0;