[for-2.6.35] virtio-pci: disable msi at startup

Commit Message

Michael S. Tsirkin June 10, 2010, 3:22 p.m. UTC

None

Patch

diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c
index 60f30e7..740fb4e 100644
--- a/drivers/pci/pci.c
+++ b/drivers/pci/pci.c
@@ -2292,6 +2292,7 @@  void pci_msi_off(struct pci_dev *dev)
 		pci_write_config_word(dev, pos + PCI_MSIX_FLAGS, control);
 	}
 }
+EXPORT_SYMBOL_GPL(pci_msi_off);
 
 #ifndef HAVE_ARCH_PCI_SET_DMA_MAX_SEGMENT_SIZE
 int pci_set_dma_max_seg_size(struct pci_dev *dev, unsigned int size)
diff --git a/drivers/virtio/virtio_pci.c b/drivers/virtio/virtio_pci.c
index 95896f3..ef8d9d5 100644
--- a/drivers/virtio/virtio_pci.c
+++ b/drivers/virtio/virtio_pci.c
@@ -636,6 +636,9 @@  static int __devinit virtio_pci_probe(struct pci_dev *pci_dev,
 	INIT_LIST_HEAD(&vp_dev->virtqueues);
 	spin_lock_init(&vp_dev->lock);
 
+	/* Disable MSI/MSIX to bring device to a known good state. */
+	pci_msi_off(pci_dev);
+
 	/* enable the device */
 	err = pci_enable_device(pci_dev);
 	if (err)
diff --git a/include/linux/pci.h b/include/linux/pci.h
index 7cb0084..31d8a12 100644
--- a/include/linux/pci.h
+++ b/include/linux/pci.h
@@ -780,7 +780,11 @@  int __must_check pci_set_mwi(struct pci_dev *dev);
 int pci_try_set_mwi(struct pci_dev *dev);
 void pci_clear_mwi(struct pci_dev *dev);
 void pci_intx(struct pci_dev *dev, int enable);
+#ifdef CONFIG_PCI_MSI
 void pci_msi_off(struct pci_dev *dev);
+#else
+static inline void pci_msi_off(struct pci_dev *dev) {}
+#endif
 int pci_set_dma_max_seg_size(struct pci_dev *dev, unsigned int size);
 int pci_set_dma_seg_boundary(struct pci_dev *dev, unsigned long mask);
 int pcix_get_max_mmrbc(struct pci_dev *dev);