sh_eth: WARN on access to a register not implemented in a particular chip

[cascardo/linux.git] / drivers / net / ethernet / renesas / sh_eth.h

diff --git a/drivers/net/ethernet/renesas/sh_eth.h b/drivers/net/ethernet/renesas/sh_eth.h
index 259d03f..33a360c 100644 (file)
--- a/drivers/net/ethernet/renesas/sh_eth.h
+++ b/drivers/net/ethernet/renesas/sh_eth.h
@@ -543,19 +543,29 @@ static inline void sh_eth_soft_swap(char *src, int len)
 #endif
 }
 
+#define SH_ETH_OFFSET_INVALID  ((u16) ~0)
+
 static inline void sh_eth_write(struct net_device *ndev, u32 data,
                                int enum_index)
 {
        struct sh_eth_private *mdp = netdev_priv(ndev);
+       u16 offset = mdp->reg_offset[enum_index];
+
+       if (WARN_ON(offset == SH_ETH_OFFSET_INVALID))
+               return;
 
-       iowrite32(data, mdp->addr + mdp->reg_offset[enum_index]);
+       iowrite32(data, mdp->addr + offset);
 }
 
 static inline u32 sh_eth_read(struct net_device *ndev, int enum_index)
 {
        struct sh_eth_private *mdp = netdev_priv(ndev);
+       u16 offset = mdp->reg_offset[enum_index];
+
+       if (WARN_ON(offset == SH_ETH_OFFSET_INVALID))
+               return ~0U;
 
-       return ioread32(mdp->addr + mdp->reg_offset[enum_index]);
+       return ioread32(mdp->addr + offset);
 }
 
 static inline void *sh_eth_tsu_get_offset(struct sh_eth_private *mdp,