Re: AMD 8131 MSI quirk called too late, bus_flags not inherited ?

["Michael S. Tsirkin" <mst@mellanox.co.il>]

Quoting r. Brice Goglin <brice@myri.com>:
> Subject: Re: AMD 8131 MSI quirk called too late, bus_flags not inherited ?
> 
> Michael S. Tsirkin wrote:
> > MSI is an optional feature so things are supposed to work even without MSI - are
> > you getting that great a benefit from MSI?
> >   
> 
> Not great, I would say small.
> 
> > All mellanox PCI-X devices have a bridge inside them, so ...
> >   
> 
> Ok so you really need something for 2.6.17. What about the attached
> patch to fix the fact that bus flags are not inherited ?
> 
> Signed-off-by: Brice Goglin <brice@myri.com>

The following applies this quirk for MSI-X as well.

Signed-off-by: Michael S. Tsirkin <mst@mellanox.co.il>

Index: linux-2.6.17-rc4/drivers/pci/msi.c
===================================================================
--- linux-2.6.17-rc4.orig/drivers/pci/msi.c	2006-05-21 12:49:52.000000000 +0300
+++ linux-2.6.17-rc4/drivers/pci/msi.c	2006-05-21 16:14:50.000000000 +0300
@@ -865,6 +865,7 @@ static int msix_capability_init(struct p
  **/
 int pci_enable_msi(struct pci_dev* dev)
 {
+	struct pci_bus *bus;
 	int pos, temp, status = -EINVAL;
 	u16 control;
 
@@ -874,8 +875,9 @@ 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;
 
@@ -1108,6 +1110,7 @@ static int reroute_msix_table(int head, 
  **/
 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;
@@ -1116,6 +1119,10 @@ int pci_enable_msix(struct pci_dev* dev,
 	if (!pci_msi_enable || !dev || !entries)
  		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;

-- 
MST