bnx2: Fix compiler warning in bnx2_disable_forced_2g5().

drivers/net/bnx2.c: In function 'bnx2_disable_forced_2g5':
drivers/net/bnx2.c:1489: warning: 'bmcr' may be used uninitialized in this function

We fix it by checking return values from all bnx2_read_phy() and proceeding
to do read-modify-write only if the read operation is successful.

The related bnx2_enable_forced_2g5() is also fixed the same way.

Reported-by: Prarit Bhargava <prarit@redhat.com>
Signed-off-by: Michael Chan <mchan@broadcom.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 28 insertions, 15 deletions

diff --git a/drivers/net/bnx2.c b/drivers/net/bnx2.c
index 949d7a9dcf92..522de9f818be 100644
--- a/drivers/net/bnx2.c
+++ b/drivers/net/bnx2.c
@@ -1446,7 +1446,8 @@ bnx2_test_and_disable_2g5(struct bnx2 *bp)
 static void
 bnx2_enable_forced_2g5(struct bnx2 *bp)
 {
-        u32 bmcr;
+        u32 uninitialized_var(bmcr);
+        int err;
 
         if (!(bp->phy_flags & BNX2_PHY_FLAG_2_5G_CAPABLE))
                 return;
@@ -1456,22 +1457,28 @@ bnx2_enable_forced_2g5(struct bnx2 *bp)
 
                 bnx2_write_phy(bp, MII_BNX2_BLK_ADDR,
                                MII_BNX2_BLK_ADDR_SERDES_DIG);
-                bnx2_read_phy(bp, MII_BNX2_SERDES_DIG_MISC1, &val);
-                val &= ~MII_BNX2_SD_MISC1_FORCE_MSK;
-                val |= MII_BNX2_SD_MISC1_FORCE | MII_BNX2_SD_MISC1_FORCE_2_5G;
-                bnx2_write_phy(bp, MII_BNX2_SERDES_DIG_MISC1, val);
+                if (!bnx2_read_phy(bp, MII_BNX2_SERDES_DIG_MISC1, &val)) {
+                        val &= ~MII_BNX2_SD_MISC1_FORCE_MSK;
+                        val |= MII_BNX2_SD_MISC1_FORCE |
+                                MII_BNX2_SD_MISC1_FORCE_2_5G;
+                        bnx2_write_phy(bp, MII_BNX2_SERDES_DIG_MISC1, val);
+                }
 
                 bnx2_write_phy(bp, MII_BNX2_BLK_ADDR,
                                MII_BNX2_BLK_ADDR_COMBO_IEEEB0);
-                bnx2_read_phy(bp, bp->mii_bmcr, &bmcr);
+                err = bnx2_read_phy(bp, bp->mii_bmcr, &bmcr);
 
         } else if (CHIP_NUM(bp) == CHIP_NUM_5708) {
-                bnx2_read_phy(bp, bp->mii_bmcr, &bmcr);
-                bmcr |= BCM5708S_BMCR_FORCE_2500;
+                err = bnx2_read_phy(bp, bp->mii_bmcr, &bmcr);
+                if (!err)
+                        bmcr |= BCM5708S_BMCR_FORCE_2500;
         } else {
                 return;
         }
 
+        if (err)
+                return;
+
         if (bp->autoneg & AUTONEG_SPEED) {
                 bmcr &= ~BMCR_ANENABLE;
                 if (bp->req_duplex == DUPLEX_FULL)
@@ -1483,7 +1490,8 @@ bnx2_enable_forced_2g5(struct bnx2 *bp)
 static void
 bnx2_disable_forced_2g5(struct bnx2 *bp)
 {
-        u32 bmcr;
+        u32 uninitialized_var(bmcr);
+        int err;
 
         if (!(bp->phy_flags & BNX2_PHY_FLAG_2_5G_CAPABLE))
                 return;
@@ -1493,21 +1501,26 @@ bnx2_disable_forced_2g5(struct bnx2 *bp)
 
                 bnx2_write_phy(bp, MII_BNX2_BLK_ADDR,
                                MII_BNX2_BLK_ADDR_SERDES_DIG);
-                bnx2_read_phy(bp, MII_BNX2_SERDES_DIG_MISC1, &val);
-                val &= ~MII_BNX2_SD_MISC1_FORCE;
-                bnx2_write_phy(bp, MII_BNX2_SERDES_DIG_MISC1, val);
+                if (!bnx2_read_phy(bp, MII_BNX2_SERDES_DIG_MISC1, &val)) {
+                        val &= ~MII_BNX2_SD_MISC1_FORCE;
+                        bnx2_write_phy(bp, MII_BNX2_SERDES_DIG_MISC1, val);
+                }
 
                 bnx2_write_phy(bp, MII_BNX2_BLK_ADDR,
                                MII_BNX2_BLK_ADDR_COMBO_IEEEB0);
-                bnx2_read_phy(bp, bp->mii_bmcr, &bmcr);
+                err = bnx2_read_phy(bp, bp->mii_bmcr, &bmcr);
 
         } else if (CHIP_NUM(bp) == CHIP_NUM_5708) {
-                bnx2_read_phy(bp, bp->mii_bmcr, &bmcr);
-                bmcr &= ~BCM5708S_BMCR_FORCE_2500;
+                err = bnx2_read_phy(bp, bp->mii_bmcr, &bmcr);
+                if (!err)
+                        bmcr &= ~BCM5708S_BMCR_FORCE_2500;
         } else {
                 return;
         }
 
+        if (err)
+                return;
+
         if (bp->autoneg & AUTONEG_SPEED)
                 bmcr |= BMCR_SPEED1000 | BMCR_ANENABLE | BMCR_ANRESTART;
         bnx2_write_phy(bp, bp->mii_bmcr, bmcr);