net: eth: Check return value in various places

eth_get_dev() can return NULL which means device_probe() fails for
that ethernet device. Add return value check in various places or
U-Boot will crash due to NULL pointer access.

With this commit, 'dm_test_eth_act' test case passes.

Signed-off-by: Bin Meng <bmeng.cn@gmail.com>
Acked-by: Joe Hershberger <joe.hershberger@ni.com>

diff --git a/net/eth.c b/net/eth.c
index c661775d1ca8f29f6d5bae58e8373d99d6e9ad6b..c542f4aa3b3b1e4f2e6fbb5db4c0ea579aefe45e 100644 (file)
--- a/net/eth.c
+++ b/net/eth.c
@@ -179,8 +179,12 @@ struct udevice *eth_get_dev(void)
  */
 static void eth_set_dev(struct udevice *dev)
 {
-       if (dev && !device_active(dev))
+       if (dev && !device_active(dev)) {
                eth_errno = device_probe(dev);
+               if (eth_errno)
+                       dev = NULL;
+       }
+
        eth_get_uclass_priv()->current = dev;
 }
 
@@ -213,10 +217,9 @@ struct udevice *eth_get_dev_by_name(const char *devname)
                 * match an alias or it will match a literal name and we'll pick
                 * up the error when we try to probe again in eth_set_dev().
                 */
-               device_probe(it);
-               /*
-                * Check for the name or the sequence number to match
-                */
+               if (device_probe(it))
+                       continue;
+               /* Check for the name or the sequence number to match */
                if (strcmp(it->name, devname) == 0 ||
                    (endp > startp && it->seq == seq))
                        return it;
@@ -346,23 +349,27 @@ int eth_init(void)
 
        old_current = current;
        do {
-               debug("Trying %s\n", current->name);
-
-               if (device_active(current)) {
-                       ret = eth_get_ops(current)->start(current);
-                       if (ret >= 0) {
-                               struct eth_device_priv *priv =
-                                       current->uclass_priv;
-
-                               priv->state = ETH_STATE_ACTIVE;
-                               return 0;
+               if (current) {
+                       debug("Trying %s\n", current->name);
+
+                       if (device_active(current)) {
+                               ret = eth_get_ops(current)->start(current);
+                               if (ret >= 0) {
+                                       struct eth_device_priv *priv =
+                                               current->uclass_priv;
+
+                                       priv->state = ETH_STATE_ACTIVE;
+                                       return 0;
+                               }
+                       } else {
+                               ret = eth_errno;
                        }
+
+                       debug("FAIL\n");
                } else {
-                       ret = eth_errno;
+                       debug("PROBE FAIL\n");
                }
 
-               debug("FAIL\n");
-
                /*
                 * If ethrotate is enabled, this will change "current",
                 * otherwise we will drop out of this while loop immediately