[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/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt
index 7b7382d0f758..44a25f3f51d1 100644
--- a/Documentation/kernel-parameters.txt
+++ b/Documentation/kernel-parameters.txt
@@ -49,6 +49,7 @@ restrictions referred to are that the relevant option is valid if:
         MCA     MCA bus support is enabled.
         MDA     MDA console support is enabled.
         MOUSE   Appropriate mouse support is enabled.
+        MSI     Message Signaled Interrupts (PCI).
         MTD     MTD support is enabled.
         NET     Appropriate network support is enabled.
         NUMA    NUMA support is enabled.
@@ -1152,6 +1153,9 @@ running once the system is up.
                                 Mechanism 2.
                 nommconf        [IA-32,X86_64] Disable use of MMCONFIG for PCI
                                 Configuration
+                nomsi           [MSI] If the PCI_MSI kernel config parameter is
+                                enabled, this kernel boot option can be used to
+                                disable the use of MSI interrupts system-wide.
                 nosort          [IA-32] Don't sort PCI devices according to
                                 order given by the PCI BIOS. This sorting is
                                 done to get a device order compatible with