[PATCH] msi: sanely support hardware level msi disabling

In some cases when we are not using msi we need a way to ensure that the
hardware does not have an msi capability enabled.  Currently the code has been
calling disable_msi_mode to try and achieve that.  However disable_msi_mode
has several other side effects and is only available when msi support is
compiled in so it isn't really appropriate.

Instead this patch implements pci_msi_off which disables all msi and msix
capabilities unconditionally with no additional side effects.

pci_disable_device was redundantly clearing the bus master enable flag and
clearing the msi enable bit.  A device that is not allowed to perform bus
mastering operations cannot generate intx or msi interrupt messages as those
are essentially a special case of dma, and require bus mastering.  So the call
in pci_disable_device to disable msi capabilities was redundant.

quirk_pcie_pxh also called disable_msi_mode and is updated to use pci_msi_off.

Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Cc: Michael Ellerman <michael@ellerman.id.au>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Greg KH <greg@kroah.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 1 insertions, 1 deletions

diff --git a/drivers/pci/msi.c b/drivers/pci/msi.c
index 68555c11f556..fd1068b59b0c 100644
--- a/drivers/pci/msi.c
+++ b/drivers/pci/msi.c
@@ -211,7 +211,7 @@ static void enable_msi_mode(struct pci_dev *dev, int pos, int type)
 	pci_intx(dev, 0);  /* disable intx */
 }
 
-void disable_msi_mode(struct pci_dev *dev, int pos, int type)
+static void disable_msi_mode(struct pci_dev *dev, int pos, int type)
 {
 	u16 control;