Merge branch 'for-4.9-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj...

Pull libata fixes from Tejun Heo:
 "The AHCI MSI handling change in rc1 was a bit broken and caused disk
  probing failures on some machines.  These three patches should fix the
  issues"

David Howells comments:
 "My test machine fell foul of this using a PCIe M.2-attached SSD card.
  The patches fix it for me"

* 'for-4.9-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/libata:
  ahci: fix the single MSI-X case in ahci_init_one
  ahci: fix nvec check
  ahci: only try to use multi-MSI mode if there is more than 1 port

diff --git a/drivers/ata/ahci.c b/drivers/ata/ahci.c
index ba5f11c..9669fc7 100644 (file)
--- a/drivers/ata/ahci.c
+++ b/drivers/ata/ahci.c
@@ -1418,30 +1418,33 @@ static int ahci_init_msi(struct pci_dev *pdev, unsigned int n_ports,
         * Message mode could be enforced. In this case assume that advantage
         * of multipe MSIs is negated and use single MSI mode instead.
         */
-       nvec = pci_alloc_irq_vectors(pdev, n_ports, INT_MAX,
-                       PCI_IRQ_MSIX | PCI_IRQ_MSI);
-       if (nvec > 0) {
-               if (!(readl(hpriv->mmio + HOST_CTL) & HOST_MRSM)) {
-                       hpriv->get_irq_vector = ahci_get_irq_vector;
-                       hpriv->flags |= AHCI_HFLAG_MULTI_MSI;
-                       return nvec;
+       if (n_ports > 1) {
+               nvec = pci_alloc_irq_vectors(pdev, n_ports, INT_MAX,
+                               PCI_IRQ_MSIX | PCI_IRQ_MSI);
+               if (nvec > 0) {
+                       if (!(readl(hpriv->mmio + HOST_CTL) & HOST_MRSM)) {
+                               hpriv->get_irq_vector = ahci_get_irq_vector;
+                               hpriv->flags |= AHCI_HFLAG_MULTI_MSI;
+                               return nvec;
+                       }
+
+                       /*
+                        * Fallback to single MSI mode if the controller
+                        * enforced MRSM mode.
+                        */
+                       printk(KERN_INFO
+                               "ahci: MRSM is on, fallback to single MSI\n");
+                       pci_free_irq_vectors(pdev);
                }
 
                /*
-                * Fallback to single MSI mode if the controller enforced MRSM
-                * mode.
+                * -ENOSPC indicated we don't have enough vectors.  Don't bother
+                * trying a single vectors for any other error:
                 */
-               printk(KERN_INFO "ahci: MRSM is on, fallback to single MSI\n");
-               pci_free_irq_vectors(pdev);
+               if (nvec < 0 && nvec != -ENOSPC)
+                       return nvec;
        }
 
-       /*
-        * -ENOSPC indicated we don't have enough vectors.  Don't bother trying
-        * a single vectors for any other error:
-        */
-       if (nvec < 0 && nvec != -ENOSPC)
-               return nvec;
-
        /*
         * If the host is not capable of supporting per-port vectors, fall
         * back to single MSI before finally attempting single MSI-X.
@@ -1617,7 +1620,7 @@ static int ahci_init_one(struct pci_dev *pdev, const struct pci_device_id *ent)
                /* legacy intx interrupts */
                pci_intx(pdev, 1);
        }
-       hpriv->irq = pdev->irq;
+       hpriv->irq = pci_irq_vector(pdev, 0);
 
        if (!(hpriv->cap & HOST_CAP_SSS) || ahci_ignore_sss)
                host->flags |= ATA_HOST_PARALLEL_SCAN;