cxgb3: ease msi-x settings conditions

The driver currently drops to line interrupt mode
if it did not get all the msi-x vectors it requested.

Allow msi-x settings when a minimal amount of vectors
is provided.

Signed-off-by: Divy Le Ray <divy@chelsio.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

2 files changed, 16 insertions, 8 deletions

diff --git a/drivers/net/cxgb3/adapter.h b/drivers/net/cxgb3/adapter.h
index a89d8cc51205..5fb7c6851eb2 100644
--- a/drivers/net/cxgb3/adapter.h
+++ b/drivers/net/cxgb3/adapter.h
@@ -230,6 +230,7 @@ struct adapter {
         unsigned int slow_intr_mask;
         unsigned long irq_stats[IRQ_NUM_STATS];
 
+        int msix_nvectors;
         struct {
                 unsigned short vec;
                 char desc[22];
diff --git a/drivers/net/cxgb3/cxgb3_main.c b/drivers/net/cxgb3/cxgb3_main.c
index 0089746b8d02..52131bd4cc70 100644
--- a/drivers/net/cxgb3/cxgb3_main.c
+++ b/drivers/net/cxgb3/cxgb3_main.c
@@ -338,7 +338,7 @@ static void free_irq_resources(struct adapter *adapter)
 
                 free_irq(adapter->msix_info[0].vec, adapter);
                 for_each_port(adapter, i)
-                    n += adap2pinfo(adapter, i)->nqsets;
+                        n += adap2pinfo(adapter, i)->nqsets;
 
                 for (i = 0; i < n; ++i)
                         free_irq(adapter->msix_info[i + 1].vec,
@@ -2752,7 +2752,7 @@ static void set_nqsets(struct adapter *adap)
         int i, j = 0;
         int num_cpus = num_online_cpus();
         int hwports = adap->params.nports;
-        int nqsets = SGE_QSETS;
+        int nqsets = adap->msix_nvectors - 1;
 
         if (adap->params.rev > 0 && adap->flags & USING_MSIX) {
                 if (hwports == 2 &&
@@ -2781,18 +2781,25 @@ static void set_nqsets(struct adapter *adap)
 static int __devinit cxgb_enable_msix(struct adapter *adap)
 {
         struct msix_entry entries[SGE_QSETS + 1];
+        int vectors;
         int i, err;
 
-        for (i = 0; i < ARRAY_SIZE(entries); ++i)
+        vectors = ARRAY_SIZE(entries);
+        for (i = 0; i < vectors; ++i)
                 entries[i].entry = i;
 
-        err = pci_enable_msix(adap->pdev, entries, ARRAY_SIZE(entries));
+        while ((err = pci_enable_msix(adap->pdev, entries, vectors)) > 0)
+                vectors = err;
+
+        if (!err && vectors < (adap->params.nports + 1))
+                err = -1;
+
         if (!err) {
-                for (i = 0; i < ARRAY_SIZE(entries); ++i)
+                for (i = 0; i < vectors; ++i)
                         adap->msix_info[i].vec = entries[i].vector;
-        } else if (err > 0)
-                dev_info(&adap->pdev->dev,
-                       "only %d MSI-X vectors left, not using MSI-X\n", err);
+                adap->msix_nvectors = vectors;
+        }
+
         return err;
 }