[PATCH] PCI: AMD 8131 MSI quirk called too late, bus_flags not inherited ?

The PCI_BUS_FLAGS_NO_MSI bus flags does not appear do be inherited
correctly from the amd8131 MSI quirk to its parent busses. It makes
devices behind a bridge behind amd8131 try to enable MSI while the
amd8131 does not support it.
We fix this by looking at flags of all parent busses in
pci_enable_msi() and pci_enable_msix().

By the way, also add the missing dev->no_msi check in pci_enable_msix()

Signed-off-by: Brice Goglin <brice@myri.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

drivers/pci/msi.c

@@ -916,6 +916,7 @@ static int msix_capability_init(struct pci_dev *dev,
  **/
 int pci_enable_msi(struct pci_dev* dev)
 {
+	struct pci_bus *bus;
 	int pos, temp, status = -EINVAL;
 	u16 control;
 
@@ -925,8 +926,9 @@ int pci_enable_msi(struct pci_dev* dev)
 	if (dev->no_msi)
 		return status;
 
-	if (dev->bus->bus_flags & PCI_BUS_FLAGS_NO_MSI)
-		return -EINVAL;
+	for (bus = dev->bus; bus; bus = bus->parent)
+		if (bus->bus_flags & PCI_BUS_FLAGS_NO_MSI)
+			return -EINVAL;
 
 	temp = dev->irq;
 
@@ -1162,6 +1164,7 @@ static int reroute_msix_table(int head, struct msix_entry *entries, int *nvec)
  **/
 int pci_enable_msix(struct pci_dev* dev, struct msix_entry *entries, int nvec)
 {
+	struct pci_bus *bus;
 	int status, pos, nr_entries, free_vectors;
 	int i, j, temp;
 	u16 control;
@@ -1170,6 +1173,13 @@ int pci_enable_msix(struct pci_dev* dev, struct msix_entry *entries, int nvec)
 	if (!pci_msi_enable || !dev || !entries)
  		return -EINVAL;
 
+	if (dev->no_msi)
+		return -EINVAL;
+
+	for (bus = dev->bus; bus; bus = bus->parent)
+		if (bus->bus_flags & PCI_BUS_FLAGS_NO_MSI)
+			return -EINVAL;
+
 	status = msi_init();
 	if (status < 0)
 		return status;