ixgbe: disable MSI-X by default on certain Cisco adapters

Due to an errata in 82598 parts MSI-X needs to be disabled
in certain ixgbe devices designed to transfer peer-to-peer
traffic on the PCIe bus. This patch sets the default
interrupt type to MSI rather than MSI-X for specific Cisco
ixgbe adapters.

Signed-off-by: Nicholas Nunley <nicholasx.d.nunley@intel.com>
Acked-by: John Ronciak <john.ronciak@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

2 files changed, 20 insertions, 1 deletions

diff --git a/drivers/net/ixgbe/ixgbe.h b/drivers/net/ixgbe/ixgbe.h
index 79c35ae3718c..ec6bcc0660c6 100644
--- a/drivers/net/ixgbe/ixgbe.h
+++ b/drivers/net/ixgbe/ixgbe.h
@@ -104,6 +104,10 @@
 #define MAX_EMULATION_MAC_ADDRS         16
 #define VMDQ_P(p)   ((p) + adapter->num_vfs)
 
+#define IXGBE_SUBDEV_ID_82598AF_MEZZ            0x0049
+#define IXGBE_SUBDEV_ID_82598AF_MENLO_Q_MEZZ    0x004a
+#define IXGBE_SUBDEV_ID_82598AF_MENLO_E_MEZZ    0x004b
+
 struct vf_data_storage {
         unsigned char vf_mac_addresses[ETH_ALEN];
         u16 vf_mc_hashes[IXGBE_MAX_VF_MC_ENTRIES];
diff --git a/drivers/net/ixgbe/ixgbe_main.c b/drivers/net/ixgbe/ixgbe_main.c
index 2ae5a5159ce4..ff59f88dc7a1 100644
--- a/drivers/net/ixgbe/ixgbe_main.c
+++ b/drivers/net/ixgbe/ixgbe_main.c
@@ -4314,6 +4314,9 @@ static int ixgbe_set_interrupt_capability(struct ixgbe_adapter *adapter)
         int err = 0;
         int vector, v_budget;
 
+        if (!(adapter->flags & IXGBE_FLAG_MSIX_CAPABLE))
+                goto try_msi;
+
         /*
          * It's easy to be greedy for MSI-X vectors, but it really
          * doesn't do us much good if we have a lot more vectors
@@ -4345,7 +4348,7 @@ static int ixgbe_set_interrupt_capability(struct ixgbe_adapter *adapter)
                 if (adapter->flags & IXGBE_FLAG_MSIX_ENABLED)
                         goto out;
         }
-
+try_msi:
         adapter->flags &= ~IXGBE_FLAG_DCB_ENABLED;
         adapter->flags &= ~IXGBE_FLAG_RSS_ENABLED;
         adapter->flags &= ~IXGBE_FLAG_FDIR_HASH_CAPABLE;
@@ -4626,6 +4629,18 @@ static int __devinit ixgbe_sw_init(struct ixgbe_adapter *adapter)
         adapter->ring_feature[RING_F_RSS].indices = rss;
         adapter->flags |= IXGBE_FLAG_RSS_ENABLED;
         adapter->ring_feature[RING_F_DCB].indices = IXGBE_MAX_DCB_INDICES;
+        adapter->flags |= IXGBE_FLAG_MSIX_CAPABLE;
+        if (adapter->hw.device_id == IXGBE_DEV_ID_82598AF_DUAL_PORT) {
+                switch (adapter->hw.subsystem_device_id) {
+                case IXGBE_SUBDEV_ID_82598AF_MEZZ:
+                case IXGBE_SUBDEV_ID_82598AF_MENLO_Q_MEZZ:
+                case IXGBE_SUBDEV_ID_82598AF_MENLO_E_MEZZ:
+                        adapter->flags &= ~IXGBE_FLAG_MSIX_CAPABLE;
+                        break;
+                default:
+                        break;
+                }
+        }
         if (hw->mac.type == ixgbe_mac_82598EB) {
                 if (hw->device_id == IXGBE_DEV_ID_82598AT)
                         adapter->flags |= IXGBE_FLAG_FAN_FAIL_CAPABLE;