[src/trunk]: src/sys/dev/pci/ixgbe - If MSI can't be used on some environment...

[msaitoh <msaitoh%NetBSD.org@localhost>]

details:   https://anonhg.NetBSD.org/src/rev/6597e9632e69
branches:  trunk
changeset: 358311:6597e9632e69
user:      msaitoh <msaitoh%NetBSD.org@localhost>
date:      Thu Dec 21 09:24:45 2017 +0000

description:
- If MSI can't be used on some environment, fallback to INTx correctly.
- Use single vector MSI when number of CPU is 1 to save interrupt slot.

diffstat:

 sys/dev/pci/ixgbe/ixgbe.c |  19 ++++++++++++++++---
 1 files changed, 16 insertions(+), 3 deletions(-)

diffs (48 lines):

diff -r f98cde664ef6 -r 6597e9632e69 sys/dev/pci/ixgbe/ixgbe.c
--- a/sys/dev/pci/ixgbe/ixgbe.c Thu Dec 21 09:04:34 2017 +0000
+++ b/sys/dev/pci/ixgbe/ixgbe.c Thu Dec 21 09:24:45 2017 +0000
@@ -1,4 +1,4 @@
-/* $NetBSD: ixgbe.c,v 1.117 2017/12/21 06:49:26 msaitoh Exp $ */
+/* $NetBSD: ixgbe.c,v 1.118 2017/12/21 09:24:45 msaitoh Exp $ */
 
 /******************************************************************************
 
@@ -5666,8 +5666,9 @@
        counts[PCI_INTR_TYPE_MSIX] = 0;
        counts[PCI_INTR_TYPE_MSI] =
            (adapter->feat_en & IXGBE_FEATURE_MSI) ? 1 : 0;
+       /* Check not feat_en but feat_cap to fallback to INTx */
        counts[PCI_INTR_TYPE_INTX] =
-           (adapter->feat_en & IXGBE_FEATURE_LEGACY_IRQ) ? 1 : 0;
+           (adapter->feat_cap & IXGBE_FEATURE_LEGACY_IRQ) ? 1 : 0;
 
 alloc_retry:
        if (pci_intr_alloc(pa, &adapter->osdep.intrs, counts, max_type) != 0) {
@@ -5691,7 +5692,12 @@
                        /* The next try is for INTx: Disable MSI */
                        max_type = PCI_INTR_TYPE_INTX;
                        counts[PCI_INTR_TYPE_INTX] = 1;
-                       goto alloc_retry;
+                       adapter->feat_en &= ~IXGBE_FEATURE_MSI;
+                       if (adapter->feat_cap & IXGBE_FEATURE_LEGACY_IRQ) {
+                               adapter->feat_en |= IXGBE_FEATURE_LEGACY_IRQ;
+                               goto alloc_retry;
+                       } else
+                               break;
                case PCI_INTR_TYPE_INTX:
                default:
                        /* See below */
@@ -5958,6 +5964,13 @@
        if (!(adapter->feat_cap & IXGBE_FEATURE_MSIX))
                goto msi;
 
+       /*
+        *  NetBSD only: Use single vector MSI when number of CPU is 1 to save
+        * interrupt slot.
+        */
+       if (ncpu == 1)
+               goto msi;
+       
        /* First try MSI-X */
        msgs = pci_msix_count(adapter->osdep.pc, adapter->osdep.tag);
        msgs = MIN(msgs, IXG_MAX_NINTR);