bnxt_en: Add PHY retry logic.

During hotplug, the driver's open function can be called almost
immediately after power on reset.  The PHY may not be ready and the
firmware may return failure when the driver tries to update PHY
settings.  Add retry logic fired from the driver's timer to retry
the operation for 5 seconds.
Signed-off-by: Michael Chan <michael.chan@broadcom.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ethernet/broadcom/bnxt/bnxt.c

@@ -6898,8 +6898,14 @@ static int __bnxt_open_nic(struct bnxt *bp, bool irq_re_init, bool link_re_init)
 		mutex_lock(&bp->link_lock);
 		rc = bnxt_update_phy_setting(bp);
 		mutex_unlock(&bp->link_lock);
-		if (rc)
+		if (rc) {
 			netdev_warn(bp->dev, "failed to update phy settings\n");
+			if (BNXT_SINGLE_PF(bp)) {
+				bp->link_info.phy_retry = true;
+				bp->link_info.phy_retry_expires =
+					jiffies + 5 * HZ;
+			}
+		}
 	}
 
 	if (irq_re_init)
@@ -7583,6 +7589,16 @@ static void bnxt_timer(struct timer_list *t)
 		set_bit(BNXT_FLOW_STATS_SP_EVENT, &bp->sp_event);
 		bnxt_queue_sp_work(bp);
 	}
+
+	if (bp->link_info.phy_retry) {
+		if (time_after(jiffies, bp->link_info.phy_retry_expires)) {
+			bp->link_info.phy_retry = 0;
+			netdev_warn(bp->dev, "failed to update phy settings after maximum retries.\n");
+		} else {
+			set_bit(BNXT_UPDATE_PHY_SP_EVENT, &bp->sp_event);
+			bnxt_queue_sp_work(bp);
+		}
+	}
 bnxt_restart_timer:
 	mod_timer(&bp->timer, jiffies + bp->current_interval);
 }
@@ -7670,6 +7686,19 @@ static void bnxt_sp_task(struct work_struct *work)
 			netdev_err(bp->dev, "SP task can't update link (rc: %x)\n",
 				   rc);
 	}
+	if (test_and_clear_bit(BNXT_UPDATE_PHY_SP_EVENT, &bp->sp_event)) {
+		int rc;
+
+		mutex_lock(&bp->link_lock);
+		rc = bnxt_update_phy_setting(bp);
+		mutex_unlock(&bp->link_lock);
+		if (rc) {
+			netdev_warn(bp->dev, "update phy settings retry failed\n");
+		} else {
+			bp->link_info.phy_retry = false;
+			netdev_info(bp->dev, "update phy settings retry succeeded\n");
+		}
+	}
 	if (test_and_clear_bit(BNXT_HWRM_PORT_MODULE_SP_EVENT, &bp->sp_event)) {
 		mutex_lock(&bp->link_lock);
 		bnxt_get_port_module_status(bp);

drivers/net/ethernet/broadcom/bnxt/bnxt.h

@@ -959,6 +959,9 @@ struct bnxt_link_info {
 	u16			advertising;	/* user adv setting */
 	bool			force_link_chng;
 
+	bool			phy_retry;
+	unsigned long		phy_retry_expires;
+
 	/* a copy of phy_qcfg output used to report link
 	 * info to VF
 	 */
@@ -1344,6 +1347,7 @@ struct bnxt {
 #define BNXT_GENEVE_DEL_PORT_SP_EVENT	13
 #define BNXT_LINK_SPEED_CHNG_SP_EVENT	14
 #define BNXT_FLOW_STATS_SP_EVENT	15
+#define BNXT_UPDATE_PHY_SP_EVENT	16
 
 	struct bnxt_hw_resc	hw_resc;
 	struct bnxt_pf_info	pf;