ixgbe: fix link issues and panic with shared interrupts for 82598

Fix possible panic/hang with shared Legacy interrupts by not enabling
interrupts when interface is down.

Also fixes an intermittent link by enabling LSC upon exit from ixgbe_intr()

This patch adds flags to ixgbe_irq_enable() to allow for some flexibility
when enabling interrupts.

Signed-off-by: Emil Tantilov <emil.s.tantilov@intel.com>
Tested-by: Stephen Ko <stephen.s.ko@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 26 insertions, 10 deletions

diff --git a/drivers/net/ixgbe/ixgbe_main.c b/drivers/net/ixgbe/ixgbe_main.c
index c35185cb27fe..c35e13c01dbe 100644
--- a/drivers/net/ixgbe/ixgbe_main.c
+++ b/drivers/net/ixgbe/ixgbe_main.c
@@ -2233,7 +2233,8 @@ static void ixgbe_set_itr(struct ixgbe_adapter *adapter)
  * ixgbe_irq_enable - Enable default interrupt generation settings
  * @adapter: board private structure
  **/
-static inline void ixgbe_irq_enable(struct ixgbe_adapter *adapter)
+static inline void ixgbe_irq_enable(struct ixgbe_adapter *adapter, bool queues,
+                                    bool flush)
 {
         u32 mask;
 
@@ -2254,8 +2255,10 @@ static inline void ixgbe_irq_enable(struct ixgbe_adapter *adapter)
                 mask |= IXGBE_EIMS_FLOW_DIR;
 
         IXGBE_WRITE_REG(&adapter->hw, IXGBE_EIMS, mask);
-        ixgbe_irq_enable_queues(adapter, ~0);
-        IXGBE_WRITE_FLUSH(&adapter->hw);
+        if (queues)
+                ixgbe_irq_enable_queues(adapter, ~0);
+        if (flush)
+                IXGBE_WRITE_FLUSH(&adapter->hw);
 
         if (adapter->num_vfs > 32) {
                 u32 eitrsel = (1 << (adapter->num_vfs - 32)) - 1;
@@ -2277,7 +2280,7 @@ static irqreturn_t ixgbe_intr(int irq, void *data)
         u32 eicr;
 
         /*
-         * Workaround for silicon errata.  Mask the interrupts
+         * Workaround for silicon errata on 82598.  Mask the interrupts
          * before the read of EICR.
          */
         IXGBE_WRITE_REG(hw, IXGBE_EIMC, IXGBE_IRQ_CLEAR_MASK);
@@ -2286,10 +2289,15 @@ static irqreturn_t ixgbe_intr(int irq, void *data)
          * therefore no explict interrupt disable is necessary */
         eicr = IXGBE_READ_REG(hw, IXGBE_EICR);
         if (!eicr) {
-                /* shared interrupt alert!
+                /*
+                 * shared interrupt alert!
                  * make sure interrupts are enabled because the read will
-                 * have disabled interrupts due to EIAM */
-                ixgbe_irq_enable(adapter);
+                 * have disabled interrupts due to EIAM
+                 * finish the workaround of silicon errata on 82598.  Unmask
+                 * the interrupt that we masked before the EICR read.
+                 */
+                if (!test_bit(__IXGBE_DOWN, &adapter->state))
+                        ixgbe_irq_enable(adapter, true, true);
                 return IRQ_NONE;        /* Not our interrupt */
         }
 
@@ -2313,6 +2321,14 @@ static irqreturn_t ixgbe_intr(int irq, void *data)
                 __napi_schedule(&(q_vector->napi));
         }
 
+        /*
+         * re-enable link(maybe) and non-queue interrupts, no flush.
+         * ixgbe_poll will re-enable the queue interrupts
+         */
+
+        if (!test_bit(__IXGBE_DOWN, &adapter->state))
+                ixgbe_irq_enable(adapter, false, false);
+
         return IRQ_HANDLED;
 }
 
@@ -3048,7 +3064,7 @@ static void ixgbe_vlan_rx_kill_vid(struct net_device *netdev, u16 vid)
         vlan_group_set_device(adapter->vlgrp, vid, NULL);
 
         if (!test_bit(__IXGBE_DOWN, &adapter->state))
-                ixgbe_irq_enable(adapter);
+                ixgbe_irq_enable(adapter, true, true);
 
         /* remove VID from filter table */
         hw->mac.ops.set_vfta(&adapter->hw, vid, pool_ndx, false);
@@ -3145,7 +3161,7 @@ static void ixgbe_vlan_rx_register(struct net_device *netdev,
         ixgbe_vlan_rx_add_vid(netdev, 0);
 
         if (!test_bit(__IXGBE_DOWN, &adapter->state))
-                ixgbe_irq_enable(adapter);
+                ixgbe_irq_enable(adapter, true, true);
 }
 
 static void ixgbe_restore_vlan(struct ixgbe_adapter *adapter)
@@ -3546,7 +3562,7 @@ static int ixgbe_up_complete(struct ixgbe_adapter *adapter)
 
         /* clear any pending interrupts, may auto mask */
         IXGBE_READ_REG(hw, IXGBE_EICR);
-        ixgbe_irq_enable(adapter);
+        ixgbe_irq_enable(adapter, true, true);
 
         /*
          * If this adapter has a fan, check to see if we had a failure