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

[Brice Goglin <brice@myri.com>]

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>

> Doesn't seem to work for me:
>
> ib_mthca: Initializing 0000:04:00.0
> GSI 18 sharing vector 0xB9 and IRQ 18
> ACPI: PCI Interrupt 0000:04:00.0[A] -> GSI 29 (level, low) -> IRQ 185
> ib_mthca 0000:04:00.0: NOP command failed to generate interrupt (IRQ 217),
> aborting.
> ib_mthca 0000:04:00.0: Try again with MSI/MSI-X disabled.
> ACPI: PCI interrupt for device 0000:04:00.0 disabled
> ib_mthca: probe of 0000:04:00.0 failed with error -16
>   

Ok. Do you at least see the quirk message ?

Thanks,
Brice

Index: linux-mm/drivers/pci/msi.c
===================================================================
--- linux-mm.orig/drivers/pci/msi.c	2006-05-21 14:25:53.000000000 +0200
+++ linux-mm/drivers/pci/msi.c	2006-05-21 14:26:56.000000000 +0200
@@ -916,6 +916,7 @@
  **/
 int pci_enable_msi(struct pci_dev* dev)
 {
+	struct pci_bus *bus;
 	int pos, temp, status = -EINVAL;
 	u16 control;
 
@@ -925,8 +926,9 @@
 	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;