Commit fd49c81f authored May 30, 2014 by Gavin Shan Committed by Alex Williamson May 30, 2014

drivers/vfio/pci: Fix wrong MSI interrupt count



According PCI local bus specification, the register of Message
Control for MSI (offset: 2, length: 2) has bit#0 to enable or
disable MSI logic and it shouldn't be part contributing to the
calculation of MSI interrupt count. The patch fixes the issue.

Signed-off-by: Gavin Shan <gwshan@linux.vnet.ibm.com>
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>

parent b13460b9

drivers/vfio/pci/vfio_pci.c

+1 −2

Original line number	Diff line number	Diff line
		@@ -197,8 +197,7 @@ static int vfio_pci_get_irq_count(struct vfio_pci_device *vdev, int irq_type)
		if (pos) {
		pci_read_config_word(vdev->pdev,
		pos + PCI_MSI_FLAGS, &flags);

		return 1 << (flags & PCI_MSI_FLAGS_QMASK);
		return 1 << ((flags & PCI_MSI_FLAGS_QMASK) >> 1);
		}
		} else if (irq_type == VFIO_PCI_MSIX_IRQ_INDEX) {
		u8 pos;