sfc: harden driver against MC resets during initial probe

This is mainly to prepare for a future overlay networking patch that
 could cause an MC reset at probe time if the UDP tunnel port list is
 set immediately upon driver load.

Signed-off-by: Edward Cree <ecree@solarflare.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/drivers/net/ethernet/sfc/efx.c b/drivers/net/ethernet/sfc/efx.c
index c28cd9d..baab0a2 100644 (file)
--- a/drivers/net/ethernet/sfc/efx.c
+++ b/drivers/net/ethernet/sfc/efx.c
@@ -3136,6 +3136,51 @@ static int efx_pci_probe_main(struct efx_nic *efx)
        return rc;
 }
 
+static int efx_pci_probe_post_io(struct efx_nic *efx)
+{
+       struct net_device *net_dev = efx->net_dev;
+       int rc = efx_pci_probe_main(efx);
+
+       if (rc)
+               return rc;
+
+       if (efx->type->sriov_init) {
+               rc = efx->type->sriov_init(efx);
+               if (rc)
+                       netif_err(efx, probe, efx->net_dev,
+                                 "SR-IOV can't be enabled rc %d\n", rc);
+       }
+
+       /* Determine netdevice features */
+       net_dev->features |= (efx->type->offload_features | NETIF_F_SG |
+                             NETIF_F_TSO | NETIF_F_RXCSUM);
+       if (efx->type->offload_features & (NETIF_F_IPV6_CSUM | NETIF_F_HW_CSUM))
+               net_dev->features |= NETIF_F_TSO6;
+       /* Check whether device supports TSO */
+       if (!efx->type->tso_versions || !efx->type->tso_versions(efx))
+               net_dev->features &= ~NETIF_F_ALL_TSO;
+       /* Mask for features that also apply to VLAN devices */
+       net_dev->vlan_features |= (NETIF_F_HW_CSUM | NETIF_F_SG |
+                                  NETIF_F_HIGHDMA | NETIF_F_ALL_TSO |
+                                  NETIF_F_RXCSUM);
+
+       net_dev->hw_features = net_dev->features & ~efx->fixed_features;
+
+       /* Disable VLAN filtering by default.  It may be enforced if
+        * the feature is fixed (i.e. VLAN filters are required to
+        * receive VLAN tagged packets due to vPort restrictions).
+        */
+       net_dev->features &= ~NETIF_F_HW_VLAN_CTAG_FILTER;
+       net_dev->features |= efx->fixed_features;
+
+       rc = efx_register_netdev(efx);
+       if (!rc)
+               return 0;
+
+       efx_pci_remove_main(efx);
+       return rc;
+}
+
 /* NIC initialisation
  *
  * This is called at module load (or hotplug insertion,
@@ -3178,42 +3223,28 @@ static int efx_pci_probe(struct pci_dev *pci_dev,
        if (rc)
                goto fail2;
 
-       rc = efx_pci_probe_main(efx);
+       rc = efx_pci_probe_post_io(efx);
+       if (rc) {
+               /* On failure, retry once immediately.
+                * If we aborted probe due to a scheduled reset, dismiss it.
+                */
+               efx->reset_pending = 0;
+               rc = efx_pci_probe_post_io(efx);
+               if (rc) {
+                       /* On another failure, retry once more
+                        * after a 50-305ms delay.
+                        */
+                       unsigned char r;
+
+                       get_random_bytes(&r, 1);
+                       msleep((unsigned int)r + 50);
+                       efx->reset_pending = 0;
+                       rc = efx_pci_probe_post_io(efx);
+               }
+       }
        if (rc)
                goto fail3;
 
-       net_dev->features |= (efx->type->offload_features | NETIF_F_SG |
-                             NETIF_F_TSO | NETIF_F_RXCSUM);
-       if (efx->type->offload_features & (NETIF_F_IPV6_CSUM | NETIF_F_HW_CSUM))
-               net_dev->features |= NETIF_F_TSO6;
-       /* Check whether device supports TSO */
-       if (!efx->type->tso_versions || !efx->type->tso_versions(efx))
-               net_dev->features &= ~NETIF_F_ALL_TSO;
-       /* Mask for features that also apply to VLAN devices */
-       net_dev->vlan_features |= (NETIF_F_HW_CSUM | NETIF_F_SG |
-                                  NETIF_F_HIGHDMA | NETIF_F_ALL_TSO |
-                                  NETIF_F_RXCSUM);
-
-       net_dev->hw_features = net_dev->features & ~efx->fixed_features;
-
-       /* Disable VLAN filtering by default.  It may be enforced if
-        * the feature is fixed (i.e. VLAN filters are required to
-        * receive VLAN tagged packets due to vPort restrictions).
-        */
-       net_dev->features &= ~NETIF_F_HW_VLAN_CTAG_FILTER;
-       net_dev->features |= efx->fixed_features;
-
-       rc = efx_register_netdev(efx);
-       if (rc)
-               goto fail4;
-
-       if (efx->type->sriov_init) {
-               rc = efx->type->sriov_init(efx);
-               if (rc)
-                       netif_err(efx, probe, efx->net_dev,
-                                 "SR-IOV can't be enabled rc %d\n", rc);
-       }
-
        netif_dbg(efx, probe, efx->net_dev, "initialisation successful\n");
 
        /* Try to create MTDs, but allow this to fail */
@@ -3232,8 +3263,6 @@ static int efx_pci_probe(struct pci_dev *pci_dev,
 
        return 0;
 
- fail4:
-       efx_pci_remove_main(efx);
  fail3:
        efx_fini_io(efx);
  fail2: