ixgbe: return integer from ixgbe_acquire_msix_vectors

Similar to how ixgbevf handles acquiring MSI-X vectors, we can return an
error code instead of relying on the flag being set. This makes it more
clear that we have failed to setup MSI-X mode, and also will make it
easier to consolidate MSI-X related code all into the single function.

Signed-off-by: Jacob Keller <jacob.e.keller@intel.com>
Tested-by: Phil Schmitt <phillip.j.schmitt@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>

1 files changed, 18 insertions, 14 deletions

diff --git a/drivers/net/ethernet/intel/ixgbe/ixgbe_lib.c b/drivers/net/ethernet/intel/ixgbe/ixgbe_lib.c
index 5d085d5ed6b7..2a388944989b 100644
--- a/drivers/net/ethernet/intel/ixgbe/ixgbe_lib.c
+++ b/drivers/net/ethernet/intel/ixgbe/ixgbe_lib.c
@@ -696,8 +696,8 @@ static void ixgbe_set_num_queues(struct ixgbe_adapter *adapter)
         ixgbe_set_rss_queues(adapter);
 }
 
-static void ixgbe_acquire_msix_vectors(struct ixgbe_adapter *adapter,
-                                       int vectors)
+static int ixgbe_acquire_msix_vectors(struct ixgbe_adapter *adapter,
+                                      int vectors)
 {
         int vector_threshold;
 
@@ -726,16 +726,22 @@ static void ixgbe_acquire_msix_vectors(struct ixgbe_adapter *adapter,
                 adapter->flags &= ~IXGBE_FLAG_MSIX_ENABLED;
                 kfree(adapter->msix_entries);
                 adapter->msix_entries = NULL;
-        } else {
-                adapter->flags |= IXGBE_FLAG_MSIX_ENABLED; /* Woot! */
-                /*
-                 * Adjust for only the vectors we'll use, which is minimum
-                 * of max_msix_q_vectors + NON_Q_VECTORS, or the number of
-                 * vectors we were allocated.
-                 */
-                vectors -= NON_Q_VECTORS;
-                adapter->num_q_vectors = min(vectors, adapter->max_q_vectors);
+
+                return vectors;
         }
+
+        /* we successfully allocated some number of vectors within our
+         * requested range.
+         */
+        adapter->flags |= IXGBE_FLAG_MSIX_ENABLED;
+
+        /* Adjust for only the vectors we'll use, which is minimum
+         * of max_q_vectors, or the number of vectors we were allocated.
+         */
+        vectors -= NON_Q_VECTORS;
+        adapter->num_q_vectors = min_t(int, vectors, adapter->max_q_vectors);
+
+        return 0;
 }
 
 static void ixgbe_add_ring(struct ixgbe_ring *ring,
@@ -1085,9 +1091,7 @@ static void ixgbe_set_interrupt_capability(struct ixgbe_adapter *adapter)
                 for (vector = 0; vector < v_budget; vector++)
                         adapter->msix_entries[vector].entry = vector;
 
-                ixgbe_acquire_msix_vectors(adapter, v_budget);
-
-                if (adapter->flags & IXGBE_FLAG_MSIX_ENABLED)
+                if (!ixgbe_acquire_msix_vectors(adapter, v_budget))
                         return;
         }