net: macb: fix network configuration error when using gmac with non-Gbit PHY

If the ethernet controller is detected as GMAC, the driver silently
assumes, that the connected PHY is also 1000Mbit capable and reads the
probably non-existant MII_STAT1000 register. This may lead to falsely
assuming a 1000Mbit link.

diff --git a/drivers/net/macb.c b/drivers/net/macb.c
index 9c2ff487a709f57eae7caa6df51a8dce7292f2cd..abeb1ae62b16daa83ee6663e1ee0468ad53354ed 100644 (file)
--- a/drivers/net/macb.c
+++ b/drivers/net/macb.c
@@ -419,6 +419,15 @@ static int macb_phy_find(struct macb_device *macb)
 }
 #endif /* CONFIG_MACB_SEARCH_PHY */
 
+#ifdef CONFIG_PHYLIB
+#define gbit_phy_support(p)    ((p)->supported &                       \
+                                       (SUPPORTED_1000baseT_Full |     \
+                                       SUPPORTED_1000baseT_Half))
+#elif defined(CONFIG_RGMII) || defined(CONFIG_GMII)
+#define gbit_phy_support(p)    1
+#else
+#define gbit_phy_support(p)    0
+#endif
 
 static int macb_phy_init(struct macb_device *macb)
 {
@@ -478,26 +487,28 @@ static int macb_phy_init(struct macb_device *macb)
 
        /* First check for GMAC */
        if (macb_is_gem(macb)) {
-               lpa = macb_mdio_read(macb, MII_STAT1000);
+               if (gbit_phy_support(phydev)) {
+                       lpa = macb_mdio_read(macb, MII_STAT1000);
 
-               if (lpa & (LPA_1000FULL | LPA_1000HALF)) {
-                       duplex = ((lpa & LPA_1000FULL) ? 1 : 0);
+                       if (lpa & (LPA_1000FULL | LPA_1000HALF)) {
+                               duplex = ((lpa & LPA_1000FULL) ? 1 : 0);
 
-                       printf("%s: link up, 1000Mbps %s-duplex (lpa: 0x%04x)\n",
-                              netdev->name,
-                              duplex ? "full" : "half",
-                              lpa);
+                               printf("%s: link up, 1000Mbps %s-duplex (lpa: 0x%04x)\n",
+                                       netdev->name,
+                                       duplex ? "full" : "half",
+                                       lpa);
 
-                       ncfgr = macb_readl(macb, NCFGR);
-                       ncfgr &= ~(MACB_BIT(SPD) | MACB_BIT(FD));
-                       ncfgr |= GEM_BIT(GBE);
+                               ncfgr = macb_readl(macb, NCFGR);
+                               ncfgr &= ~(MACB_BIT(SPD) | MACB_BIT(FD));
+                               ncfgr |= GEM_BIT(GBE);
 
-                       if (duplex)
-                               ncfgr |= MACB_BIT(FD);
+                               if (duplex)
+                                       ncfgr |= MACB_BIT(FD);
 
-                       macb_writel(macb, NCFGR, ncfgr);
+                               macb_writel(macb, NCFGR, ncfgr);
 
-                       return 1;
+                               return 1;
+                       }
                }
        }