net: Improve error handling

[karo-tx-uboot.git] / net / eth.c

diff --git a/net/eth.c b/net/eth.c
index b6c2af3de6a9deacdf9b29b8432dcc9de95590e5..13b7723bb47e545bdf480ccd65c2654f1e74ba35 100644 (file)
--- a/net/eth.c
+++ b/net/eth.c
@@ -98,6 +98,9 @@ struct eth_uclass_priv {
        struct udevice *current;
 };
 
+/* eth_errno - This stores the most recent failure code from DM functions */
+static int eth_errno;
+
 static struct eth_uclass_priv *eth_get_uclass_priv(void)
 {
        struct uclass *uc;
@@ -118,20 +121,32 @@ static void eth_set_current_to_next(void)
                uclass_first_device(UCLASS_ETH, &uc_priv->current);
 }
 
+/*
+ * Typically this will simply return the active device.
+ * In the case where the most recent active device was unset, this will attempt
+ * to return the first device. If that device doesn't exist or fails to probe,
+ * this function will return NULL.
+ */
 struct udevice *eth_get_dev(void)
 {
        struct eth_uclass_priv *uc_priv;
 
        uc_priv = eth_get_uclass_priv();
        if (!uc_priv->current)
-               uclass_first_device(UCLASS_ETH,
+               eth_errno = uclass_first_device(UCLASS_ETH,
                                    &uc_priv->current);
        return uc_priv->current;
 }
 
+/*
+ * Typically this will just store a device pointer.
+ * In case it was not probed, we will attempt to do so.
+ * dev may be NULL to unset the active device.
+ */
 static void eth_set_dev(struct udevice *dev)
 {
-       device_probe(dev);
+       if (dev && !device_active(dev))
+               eth_errno = device_probe(dev);
        eth_get_uclass_priv()->current = dev;
 }
 
@@ -155,7 +170,14 @@ struct udevice *eth_get_dev_by_name(const char *devname)
 
        uclass_get(UCLASS_ETH, &uc);
        uclass_foreach_dev(it, uc) {
-               /* We need the seq to be valid, so make sure it's probed */
+               /*
+                * We need the seq to be valid, so try to probe it.
+                * If the probe fails, the seq will not match since it will be
+                * -1 instead of what we are looking for.
+                * We don't care about errors from probe here. Either they won't
+                * 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
@@ -221,6 +243,7 @@ int eth_init(void)
 {
        struct udevice *current;
        struct udevice *old_current;
+       int ret = -ENODEV;
 
        current = eth_get_dev();
        if (!current) {
@@ -243,22 +266,29 @@ int eth_init(void)
                        else
                                memset(pdata->enetaddr, 0, 6);
 
-                       if (eth_get_ops(current)->start(current) >= 0) {
+                       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");
 
-               /* This will ensure the new "current" attempted to probe */
+               /*
+                * If ethrotate is enabled, this will change "current",
+                * otherwise we will drop out of this while loop immediately
+                */
                eth_try_another(0);
+               /* This will ensure the new "current" attempted to probe */
                current = eth_get_dev();
        } while (old_current != current);
 
-       return -ENODEV;
+       return ret;
 }
 
 void eth_halt(void)
@@ -278,6 +308,7 @@ void eth_halt(void)
 int eth_send(void *packet, int length)
 {
        struct udevice *current;
+       int ret;
 
        current = eth_get_dev();
        if (!current)
@@ -286,7 +317,12 @@ int eth_send(void *packet, int length)
        if (!device_active(current))
                return -EINVAL;
 
-       return eth_get_ops(current)->send(current, packet, length);
+       ret = eth_get_ops(current)->send(current, packet, length);
+       if (ret < 0) {
+               /* We cannot completely return the error at present */
+               debug("%s: send() returned error %d\n", __func__, ret);
+       }
+       return ret;
 }
 
 int eth_rx(void)
@@ -313,6 +349,10 @@ int eth_rx(void)
        }
        if (ret == -EAGAIN)
                ret = 0;
+       if (ret < 0) {
+               /* We cannot completely return the error at present */
+               debug("%s: recv() returned error %d\n", __func__, ret);
+       }
        return ret;
 }