xen: don't setup acpi interrupt unless there is one

Impact: compatibility with non-ACPI machines

If the SCI hasn't been set, then presumably we're not running
with acpi, don't bother setting up the interrupt.

Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>

diff --git a/arch/x86/xen/pci.c b/arch/x86/xen/pci.c
index 402a5bd39e6f34bfbed13a787aeb90534173ecd0..00ad6dffb176c00f8a5cd2e04d218588d02a3dfe 100644 (file)
--- a/arch/x86/xen/pci.c
+++ b/arch/x86/xen/pci.c
@@ -69,13 +69,12 @@ void __init xen_setup_pirqs(void)
        /*
         * Set up acpi interrupt in acpi_gbl_FADT.sci_interrupt.
         */
-       irq = xen_allocate_pirq(acpi_gbl_FADT.sci_interrupt);
+       if (acpi_gbl_FADT.sci_interrupt > 0) {
+               irq = xen_allocate_pirq(acpi_gbl_FADT.sci_interrupt);
 
-       printk(KERN_INFO "xen: allocated irq %d for acpi %d\n",
-              irq, acpi_gbl_FADT.sci_interrupt);
-
-       /* Blerk. */
-       acpi_gbl_FADT.sci_interrupt = irq;
+               printk(KERN_INFO "xen: allocated irq %d for acpi %d\n",
+                      irq, acpi_gbl_FADT.sci_interrupt);
+       }
 #endif
 
        /* Pre-allocate legacy irqs */