[PATCH RFC 26/77] cxgb4: Update MSI/MSI-X interrupts enablement code

[Alexander Gordeev]

As result of recent re-design of the MSI/MSI-X interrupts enabling
pattern this driver has to be updated to use the new technique to
obtain a optimal number of MSI/MSI-X interrupts required.

Signed-off-by: Alexander Gordeev <agordeev at redhat.com>
---
 drivers/net/ethernet/chelsio/cxgb4/cxgb4_main.c |   62 +++++++++++++----------
 1 files changed, 35 insertions(+), 27 deletions(-)

diff --git a/drivers/net/ethernet/chelsio/cxgb4/cxgb4_main.c b/drivers/net/ethernet/chelsio/cxgb4/cxgb4_main.c
index 9425bc6..e5fbbd3 100644
--- a/drivers/net/ethernet/chelsio/cxgb4/cxgb4_main.c
+++ b/drivers/net/ethernet/chelsio/cxgb4/cxgb4_main.c
@@ -5699,9 +5699,6 @@ static int enable_msix(struct adapter *adap)
 	unsigned int nchan = adap->params.nports;
 	struct msix_entry entries[MAX_INGQ + 1];
 
-	for (i = 0; i < ARRAY_SIZE(entries); ++i)
-		entries[i].entry = i;
-
 	want = s->max_ethqsets + EXTRA_VECS;
 	if (is_offload(adap)) {
 		want += s->rdmaqs + s->ofldqsets;
@@ -5710,34 +5707,45 @@ static int enable_msix(struct adapter *adap)
 	}
 	need = adap->params.nports + EXTRA_VECS + ofld_need;
 
-	while ((err = pci_enable_msix(adap->pdev, entries, want)) >= need)
-		want = err;
+	err = pci_msix_table_size(adap->pdev);
+	if (err < 0)
+		return err;
 
-	if (!err) {
-		/*
-		 * Distribute available vectors to the various queue groups.
-		 * Every group gets its minimum requirement and NIC gets top
-		 * priority for leftovers.
-		 */
-		i = want - EXTRA_VECS - ofld_need;
-		if (i < s->max_ethqsets) {
-			s->max_ethqsets = i;
-			if (i < s->ethqsets)
-				reduce_ethqs(adap, i);
-		}
-		if (is_offload(adap)) {
-			i = want - EXTRA_VECS - s->max_ethqsets;
-			i -= ofld_need - nchan;
-			s->ofldqsets = (i / nchan) * nchan;  /* round down */
-		}
-		for (i = 0; i < want; ++i)
-			adap->msix_info[i].vec = entries[i].vector;
-	} else if (err > 0) {
+	want = min(want, err);
+	if (want < need) {
 		dev_info(adap->pdev_dev,
 			 "only %d MSI-X vectors left, not using MSI-X\n", err);
-		err = -ENOSPC;
+		return -ENOSPC;
 	}
-	return err;
+
+	BUG_ON(want > ARRAY_SIZE(entries));
+	for (i = 0; i < want; ++i)
+		entries[i].entry = i;
+
+	err = pci_enable_msix(adap->pdev, entries, want);
+	if (err)
+		return err;
+
+	/*
+	 * Distribute available vectors to the various queue groups.
+	 * Every group gets its minimum requirement and NIC gets top
+	 * priority for leftovers.
+	 */
+	i = want - EXTRA_VECS - ofld_need;
+	if (i < s->max_ethqsets) {
+		s->max_ethqsets = i;
+		if (i < s->ethqsets)
+			reduce_ethqs(adap, i);
+	}
+	if (is_offload(adap)) {
+		i = want - EXTRA_VECS - s->max_ethqsets;
+		i -= ofld_need - nchan;
+		s->ofldqsets = (i / nchan) * nchan;  /* round down */
+	}
+	for (i = 0; i < want; ++i)
+		adap->msix_info[i].vec = entries[i].vector;
+
+	return 0;
 }
 
 #undef EXTRA_VECS
-- 
1.7.7.6