[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, 6 insertions, 2 deletions

diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c
index 0bf6d254426b..03af23238939 100644
--- a/drivers/pci/pci.c
+++ b/drivers/pci/pci.c
@@ -900,8 +900,12 @@ static int __devinit pci_setup(char *str)
                 if (k)
                         *k++ = 0;
                 if (*str && (str = pcibios_setup(str)) && *str) {
-                        /* PCI layer options should be handled here */
-                        printk(KERN_ERR "PCI: Unknown option `%s'\n", str);
+                        if (!strcmp(str, "nomsi")) {
+                                pci_no_msi();
+                        } else {
+                                printk(KERN_ERR "PCI: Unknown option `%s'\n",
+                                                str);
+                        }
                 }
                 str = k;
         }