1 files changed, 9 insertions, 2 deletions

diff --git a/drivers/pci/msi.c b/drivers/pci/msi.c
index 896a15d70f5b..baba2eb5367d 100644
--- a/drivers/pci/msi.c
+++ b/drivers/pci/msi.c
@@ -103,6 +103,14 @@ static void msix_set_enable(struct pci_dev *dev, int enable)
         }
 }
 
+static inline __attribute_const__ u32 msi_mask(unsigned x)
+{
+        /* Don't shift by >= width of type */
+        if (x >= 5)
+                return 0xffffffff;
+        return (1 << (1 << x)) - 1;
+}
+
 static void msix_flush_writes(struct irq_desc *desc)
 {
         struct msi_desc *entry;
@@ -407,8 +415,7 @@ static int msi_capability_init(struct pci_dev *dev)
 
                 /* All MSIs are unmasked by default, Mask them all */
                 pci_read_config_dword(dev, base, &maskbits);
-                temp = (1 << multi_msi_capable(control));
-                temp = ((temp - 1) & ~temp);
+                temp = msi_mask((control & PCI_MSI_FLAGS_QMASK) >> 1);
                 maskbits |= temp;
                 pci_write_config_dword(dev, base, maskbits);
                 entry->msi_attrib.maskbits_mask = temp;