PCI: Call pci_intx() when using legacy interrupts in pci_alloc_irq_vectors()

ahci currently insists on an explicit call to pci_intx() before falling
back from MSI or MSI-X to legacy IRQs.  As pci_intx() is a no-op if the
command register already contains the right value it seems safe and useful
to add this call to pci_alloc_irq_vectors() so that ahci can just use
pci_alloc_irq_vectors().

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>

diff --git a/drivers/pci/msi.c b/drivers/pci/msi.c
index 9233e7f..593698e 100644 (file)
--- a/drivers/pci/msi.c
+++ b/drivers/pci/msi.c
@@ -1200,8 +1200,11 @@ int pci_alloc_irq_vectors(struct pci_dev *dev, unsigned int min_vecs,
        }
 
        /* use legacy irq if allowed */
-       if ((flags & PCI_IRQ_LEGACY) && min_vecs == 1)
+       if ((flags & PCI_IRQ_LEGACY) && min_vecs == 1) {
+               pci_intx(dev, 1);
                return 1;
+       }
+
        return vecs;
 }
 EXPORT_SYMBOL(pci_alloc_irq_vectors);