1 files changed, 15 insertions, 5 deletions

diff --git a/arch/x86/kernel/io_apic.c b/arch/x86/kernel/io_apic.c
index c0498daf01c3..0480d06a12a4 100644
--- a/arch/x86/kernel/io_apic.c
+++ b/arch/x86/kernel/io_apic.c
@@ -3812,14 +3812,24 @@ int __init io_apic_get_redir_entries (int ioapic)
 
 void __init probe_nr_irqs_gsi(void)
 {
-        int idx;
         int nr = 0;
 
-        for (idx = 0; idx < nr_ioapics; idx++)
-                nr += io_apic_get_redir_entries(idx) + 1;
-
-        if (nr > nr_irqs_gsi)
+        nr = acpi_probe_gsi();
+        if (nr > nr_irqs_gsi) {
                 nr_irqs_gsi = nr;
+        } else {
+                /* for acpi=off or acpi is not compiled in */
+                int idx;
+
+                nr = 0;
+                for (idx = 0; idx < nr_ioapics; idx++)
+                        nr += io_apic_get_redir_entries(idx) + 1;
+
+                if (nr > nr_irqs_gsi)
+                        nr_irqs_gsi = nr;
+        }
+
+        printk(KERN_DEBUG "nr_irqs_gsi: %d\n", nr_irqs_gsi);
 }
 
 #ifdef CONFIG_SPARSE_IRQ