e1000: fix adapter led blinking inconsistency

Several e1000 adapters were not blinking correctly or inconsistently. This
patch cleans this up and makes them all behave the same as far as possible.

Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
Signed-off-by: Auke Kok <auke-jan.h.kok@intel.com>

diff --git a/drivers/net/e1000/e1000_hw.c b/drivers/net/e1000/e1000_hw.c
index 749d621..1c5b184 100644
--- a/drivers/net/e1000/e1000_hw.c
+++ b/drivers/net/e1000/e1000_hw.c
@@ -5537,6 +5537,44 @@
 }
 
 /******************************************************************************
+ * Used on 82571 and later Si that has LED blink bits.
+ * Callers must use their own timer and should have already called
+ * e1000_id_led_init()
+ * Call e1000_cleanup led() to stop blinking
+ *
+ * hw - Struct containing variables accessed by shared code
+ *****************************************************************************/
+int32_t
+e1000_blink_led_start(struct e1000_hw *hw)
+{
+    int16_t  i;
+    uint32_t ledctl_blink = 0;
+
+    DEBUGFUNC("e1000_id_led_blink_on");
+
+    if (hw->mac_type < e1000_82571) {
+        /* Nothing to do */
+        return E1000_SUCCESS;
+    }
+    if (hw->media_type == e1000_media_type_fiber) {
+        /* always blink LED0 for PCI-E fiber */
+        ledctl_blink = E1000_LEDCTL_LED0_BLINK |
+                     (E1000_LEDCTL_MODE_LED_ON << E1000_LEDCTL_LED0_MODE_SHIFT);
+    } else {
+        /* set the blink bit for each LED that's "on" (0x0E) in ledctl_mode2 */
+        ledctl_blink = hw->ledctl_mode2;
+        for (i=0; i < 4; i++)
+            if (((hw->ledctl_mode2 >> (i * 8)) & 0xFF) ==
+                E1000_LEDCTL_MODE_LED_ON)
+                ledctl_blink |= (E1000_LEDCTL_LED0_BLINK << (i * 8));
+    }
+
+    E1000_WRITE_REG(hw, LEDCTL, ledctl_blink);
+
+    return E1000_SUCCESS;
+}
+
+/******************************************************************************
  * Restores the saved state of the SW controlable LED.
  *
  * hw - Struct containing variables accessed by shared code