[BNX2]: Fix 5706 serdes link down bug.

1. Correct the MII expansion serdes control register definition.
2. Check an additional RUDI_INVALID bit when determining 5706S link.
Signed-off-by: Michael Chan <mchan@broadcom.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/bnx2.c

@@ -5315,7 +5315,7 @@ bnx2_5706_serdes_has_link(struct bnx2 *bp)
 	bnx2_read_phy(bp, MII_BNX2_MISC_SHADOW, &an_dbg);
 	bnx2_read_phy(bp, MII_BNX2_MISC_SHADOW, &an_dbg);
 
-	if (an_dbg & MISC_SHDW_AN_DBG_NOSYNC)
+	if (an_dbg & (MISC_SHDW_AN_DBG_NOSYNC | MISC_SHDW_AN_DBG_RUDI_INVALID))
 		return 0;
 
 	bnx2_write_phy(bp, MII_BNX2_DSP_ADDRESS, MII_EXPAND_REG1);

drivers/net/bnx2.h

@@ -6346,11 +6346,12 @@ struct l2_fhdr {
 #define MII_BNX2_DSP_EXPAND_REG			 0x0f00
 #define MII_EXPAND_REG1				  (MII_BNX2_DSP_EXPAND_REG | 1)
 #define MII_EXPAND_REG1_RUDI_C			   0x20
-#define MII_EXPAND_SERDES_CTL			  (MII_BNX2_DSP_EXPAND_REG | 2)
+#define MII_EXPAND_SERDES_CTL			  (MII_BNX2_DSP_EXPAND_REG | 3)
 
 #define MII_BNX2_MISC_SHADOW			0x1c
 #define MISC_SHDW_AN_DBG			 0x6800
 #define MISC_SHDW_AN_DBG_NOSYNC			  0x0002
+#define MISC_SHDW_AN_DBG_RUDI_INVALID		  0x0100
 #define MISC_SHDW_MODE_CTL			 0x7c00
 #define MISC_SHDW_MODE_CTL_SIG_DET		  0x0010