net: dsa: better error reporting

Add additional error reporting to the generic DSA code, so it's easier
to debug when things go wrong.  This was useful when initially bringing
up 88e6176 on a new board.

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Acked-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 16 insertions, 8 deletions

diff --git a/net/dsa/slave.c b/net/dsa/slave.c
index 5f65f929902e..4f607bc2a845 100644
--- a/net/dsa/slave.c
+++ b/net/dsa/slave.c
@@ -1026,8 +1026,10 @@ static int dsa_slave_phy_connect(struct dsa_slave_priv *p,
         struct dsa_switch *ds = p->parent;
 
         p->phy = ds->slave_mii_bus->phy_map[addr];
-        if (!p->phy)
+        if (!p->phy) {
+                netdev_err(slave_dev, "no phy at %d\n", addr);
                 return -ENODEV;
+        }
 
         /* Use already configured phy mode */
         if (p->phy_interface == PHY_INTERFACE_MODE_NA)
@@ -1061,7 +1063,7 @@ static int dsa_slave_phy_setup(struct dsa_slave_priv *p,
                  */
                 ret = of_phy_register_fixed_link(port_dn);
                 if (ret) {
-                        netdev_err(slave_dev, "failed to register fixed PHY\n");
+                        netdev_err(slave_dev, "failed to register fixed PHY: %d\n", ret);
                         return ret;
                 }
                 phy_is_fixed = true;
@@ -1072,17 +1074,20 @@ static int dsa_slave_phy_setup(struct dsa_slave_priv *p,
                 phy_flags = ds->drv->get_phy_flags(ds, p->port);
 
         if (phy_dn) {
-                ret = of_mdio_parse_addr(&slave_dev->dev, phy_dn);
+                int phy_id = of_mdio_parse_addr(&slave_dev->dev, phy_dn);
+
                 /* If this PHY address is part of phys_mii_mask, which means
                  * that we need to divert reads and writes to/from it, then we
                  * want to bind this device using the slave MII bus created by
                  * DSA to make that happen.
                  */
-                if (!phy_is_fixed && ret >= 0 &&
-                    (ds->phys_mii_mask & (1 << ret))) {
-                        ret = dsa_slave_phy_connect(p, slave_dev, ret);
-                        if (ret)
+                if (!phy_is_fixed && phy_id >= 0 &&
+                    (ds->phys_mii_mask & (1 << phy_id))) {
+                        ret = dsa_slave_phy_connect(p, slave_dev, phy_id);
+                        if (ret) {
+                                netdev_err(slave_dev, "failed to connect to phy%d: %d\n", phy_id, ret);
                                 return ret;
+                        }
                 } else {
                         p->phy = of_phy_connect(slave_dev, phy_dn,
                                                 dsa_slave_adjust_link,
@@ -1099,8 +1104,10 @@ static int dsa_slave_phy_setup(struct dsa_slave_priv *p,
          */
         if (!p->phy) {
                 ret = dsa_slave_phy_connect(p, slave_dev, p->port);
-                if (ret)
+                if (ret) {
+                        netdev_err(slave_dev, "failed to connect to port %d: %d\n", p->port, ret);
                         return ret;
+                }
         } else {
                 netdev_info(slave_dev, "attached PHY at address %d [%s]\n",
                             p->phy->addr, p->phy->drv->name);
@@ -1212,6 +1219,7 @@ int dsa_slave_create(struct dsa_switch *ds, struct device *parent,
 
         ret = dsa_slave_phy_setup(p, slave_dev);
         if (ret) {
+                netdev_err(master, "error %d setting up slave phy\n", ret);
                 free_netdev(slave_dev);
                 return ret;
         }