[PATCH] PCI: Provide a boot parameter to disable MSI

Several drivers are starting to grow options to disable MSI.  However,
it's often a host chipset issue, not something which individual drivers
should handle.  So we add the pci=nomsi kernel parameter to allow the user
to disable MSI modes for systems we haven't added to the quirk list yet.

Signed-off-by: Matthew Wilcox <matthew@wil.cx>
Signed-off-by: Randy Dunlap <rdunlap@xenotime.net>
Acked-by: Jeff Garzik <jeff@garzik.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

1 files changed, 4 insertions, 0 deletions

diff --git a/drivers/pci/Kconfig b/drivers/pci/Kconfig
index d3dcce815d15..4d762fc4878c 100644
--- a/drivers/pci/Kconfig
+++ b/drivers/pci/Kconfig
@@ -11,6 +11,10 @@ config PCI_MSI
            generate an interrupt using an inbound Memory Write on its
            PCI bus instead of asserting a device IRQ pin.
 
+           Use of PCI MSI interrupts can be disabled at kernel boot time
+           by using the 'pci=nomsi' option.  This disables MSI for the
+           entire system.
+
            If you don't know what to do here, say N.
 
 config PCI_DEBUG