[BNX2]: Add link-down workaround on 5706 serdes.

In some blade systems using the 5706 serdes, the hardware sometimes
does not properly generate link down interrupts.  We add a workaround
in the driver's timer to force a link-down when some PHY registers
report loss of SYNC.

The parallel detect logic is cleaned up slightly to better integrate
the workaround.

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

2 files changed, 90 insertions, 16 deletions

diff --git a/drivers/net/bnx2.c b/drivers/net/bnx2.c
index 18ed8068dc2d..c03f67735bf4 100644
--- a/drivers/net/bnx2.c
+++ b/drivers/net/bnx2.c
@@ -1186,6 +1186,19 @@ bnx2_disable_forced_2g5(struct bnx2 *bp)
         bnx2_write_phy(bp, bp->mii_bmcr, bmcr);
 }
 
+static void
+bnx2_5706s_force_link_dn(struct bnx2 *bp, int start)
+{
+        u32 val;
+
+        bnx2_write_phy(bp, MII_BNX2_DSP_ADDRESS, MII_EXPAND_SERDES_CTL);
+        bnx2_read_phy(bp, MII_BNX2_DSP_RW_PORT, &val);
+        if (start)
+                bnx2_write_phy(bp, MII_BNX2_DSP_RW_PORT, val & 0xff0f);
+        else
+                bnx2_write_phy(bp, MII_BNX2_DSP_RW_PORT, val | 0xc0);
+}
+
 static int
 bnx2_set_link(struct bnx2 *bp)
 {
@@ -1211,6 +1224,10 @@ bnx2_set_link(struct bnx2 *bp)
             (CHIP_NUM(bp) == CHIP_NUM_5706)) {
                 u32 val;
 
+                if (bp->phy_flags & PHY_FORCED_DOWN_FLAG) {
+                        bnx2_5706s_force_link_dn(bp, 0);
+                        bp->phy_flags &= ~PHY_FORCED_DOWN_FLAG;
+                }
                 val = REG_RD(bp, BNX2_EMAC_STATUS);
                 if (val & BNX2_EMAC_STATUS_LINK)
                         bmsr |= BMSR_LSTATUS;
@@ -1239,7 +1256,15 @@ bnx2_set_link(struct bnx2 *bp)
                     (bp->autoneg & AUTONEG_SPEED))
                         bnx2_disable_forced_2g5(bp);
 
-                bp->phy_flags &= ~PHY_PARALLEL_DETECT_FLAG;
+                if (bp->phy_flags & PHY_PARALLEL_DETECT_FLAG) {
+                        u32 bmcr;
+
+                        bnx2_read_phy(bp, bp->mii_bmcr, &bmcr);
+                        bmcr |= BMCR_ANENABLE;
+                        bnx2_write_phy(bp, bp->mii_bmcr, bmcr);
+
+                        bp->phy_flags &= ~PHY_PARALLEL_DETECT_FLAG;
+                }
                 bp->link_up = 0;
         }
 
@@ -5276,13 +5301,51 @@ bnx2_test_intr(struct bnx2 *bp)
         return -ENODEV;
 }
 
+static int
+bnx2_5706_serdes_has_link(struct bnx2 *bp)
+{
+        u32 mode_ctl, an_dbg, exp;
+
+        bnx2_write_phy(bp, MII_BNX2_MISC_SHADOW, MISC_SHDW_MODE_CTL);
+        bnx2_read_phy(bp, MII_BNX2_MISC_SHADOW, &mode_ctl);
+
+        if (!(mode_ctl & MISC_SHDW_MODE_CTL_SIG_DET))
+                return 0;
+
+        bnx2_write_phy(bp, MII_BNX2_MISC_SHADOW, MISC_SHDW_AN_DBG);
+        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)
+                return 0;
+
+        bnx2_write_phy(bp, MII_BNX2_DSP_ADDRESS, MII_EXPAND_REG1);
+        bnx2_read_phy(bp, MII_BNX2_DSP_RW_PORT, &exp);
+        bnx2_read_phy(bp, MII_BNX2_DSP_RW_PORT, &exp);
+
+        if (exp & MII_EXPAND_REG1_RUDI_C)       /* receiving CONFIG */
+                return 0;
+
+        return 1;
+}
+
 static void
 bnx2_5706_serdes_timer(struct bnx2 *bp)
 {
+        int check_link = 1;
+
         spin_lock(&bp->phy_lock);
-        if (bp->serdes_an_pending)
+        if (bp->phy_flags & PHY_FORCED_DOWN_FLAG) {
+                bnx2_5706s_force_link_dn(bp, 0);
+                bp->phy_flags &= ~PHY_FORCED_DOWN_FLAG;
+                spin_unlock(&bp->phy_lock);
+                return;
+        }
+
+        if (bp->serdes_an_pending) {
                 bp->serdes_an_pending--;
-        else if ((bp->link_up == 0) && (bp->autoneg & AUTONEG_SPEED)) {
+                check_link = 0;
+        } else if ((bp->link_up == 0) && (bp->autoneg & AUTONEG_SPEED)) {
                 u32 bmcr;
 
                 bp->current_interval = bp->timer_interval;
@@ -5290,19 +5353,7 @@ bnx2_5706_serdes_timer(struct bnx2 *bp)
                 bnx2_read_phy(bp, bp->mii_bmcr, &bmcr);
 
                 if (bmcr & BMCR_ANENABLE) {
-                        u32 phy1, phy2;
-
-                        bnx2_write_phy(bp, 0x1c, 0x7c00);
-                        bnx2_read_phy(bp, 0x1c, &phy1);
-
-                        bnx2_write_phy(bp, 0x17, 0x0f01);
-                        bnx2_read_phy(bp, 0x15, &phy2);
-                        bnx2_write_phy(bp, 0x17, 0x0f01);
-                        bnx2_read_phy(bp, 0x15, &phy2);
-
-                        if ((phy1 & 0x10) &&    /* SIGNAL DETECT */
-                                !(phy2 & 0x20)) {       /* no CONFIG */
-
+                        if (bnx2_5706_serdes_has_link(bp)) {
                                 bmcr &= ~BMCR_ANENABLE;
                                 bmcr |= BMCR_SPEED1000 | BMCR_FULLDPLX;
                                 bnx2_write_phy(bp, bp->mii_bmcr, bmcr);
@@ -5314,6 +5365,7 @@ bnx2_5706_serdes_timer(struct bnx2 *bp)
                  (bp->phy_flags & PHY_PARALLEL_DETECT_FLAG)) {
                 u32 phy2;
 
+                check_link = 0;
                 bnx2_write_phy(bp, 0x17, 0x0f01);
                 bnx2_read_phy(bp, 0x15, &phy2);
                 if (phy2 & 0x20) {
@@ -5328,6 +5380,18 @@ bnx2_5706_serdes_timer(struct bnx2 *bp)
         } else
                 bp->current_interval = bp->timer_interval;
 
+        if (bp->link_up && (bp->autoneg & AUTONEG_SPEED) && check_link) {
+                u32 val;
+
+                bnx2_write_phy(bp, MII_BNX2_MISC_SHADOW, MISC_SHDW_AN_DBG);
+                bnx2_read_phy(bp, MII_BNX2_MISC_SHADOW, &val);
+                bnx2_read_phy(bp, MII_BNX2_MISC_SHADOW, &val);
+
+                if (val & MISC_SHDW_AN_DBG_NOSYNC) {
+                        bnx2_5706s_force_link_dn(bp, 1);
+                        bp->phy_flags |= PHY_FORCED_DOWN_FLAG;
+                }
+        }
         spin_unlock(&bp->phy_lock);
 }
 
diff --git a/drivers/net/bnx2.h b/drivers/net/bnx2.h
index c1ab30b0f87a..31a030a6e2a5 100644
--- a/drivers/net/bnx2.h
+++ b/drivers/net/bnx2.h
@@ -6344,6 +6344,15 @@ struct l2_fhdr {
 #define MII_BNX2_DSP_RW_PORT                    0x15
 #define MII_BNX2_DSP_ADDRESS                    0x17
 #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_BNX2_MISC_SHADOW                    0x1c
+#define MISC_SHDW_AN_DBG                         0x6800
+#define MISC_SHDW_AN_DBG_NOSYNC                   0x0002
+#define MISC_SHDW_MODE_CTL                       0x7c00
+#define MISC_SHDW_MODE_CTL_SIG_DET                0x0010
 
 #define MII_BNX2_BLK_ADDR                       0x1f
 #define MII_BNX2_BLK_ADDR_IEEE0                  0x0000
@@ -6643,6 +6652,7 @@ struct bnx2 {
 #define PHY_INT_MODE_LINK_READY_FLAG    0x200
 #define PHY_DIS_EARLY_DAC_FLAG          0x400
 #define REMOTE_PHY_CAP_FLAG             0x800
+#define PHY_FORCED_DOWN_FLAG            0x1000
 
         u32                     mii_bmcr;
         u32                     mii_bmsr;