[IA64] Don't assume legacy com2

If com1 isn't at a legacy I/O port address, don't assume legacy com2 exists.

Signed-off-by: Alex Williamson <alex.williamson@hp.com>

diff --git a/xen/arch/ia64/xen/xensetup.c b/xen/arch/ia64/xen/xensetup.c
index 37de379e2a84127833823d9ef4b0d337c328cde9..8909136b26e351b2fb6ce9b2af9442e7fa4b73be 100644 (file)
--- a/xen/arch/ia64/xen/xensetup.c
+++ b/xen/arch/ia64/xen/xensetup.c
@@ -267,13 +267,16 @@ void start_kernel(void)
     early_setup_arch(&cmdline);
 
     /* We initialise the serial devices very early so we can get debugging. */
-    if (running_on_sim) hpsim_serial_init();
+    if (running_on_sim)
+        hpsim_serial_init();
     else {
-       ns16550_init(0, &ns16550_com1);
-       /* Also init com2 for Tiger4. */
-       ns16550_com2.io_base = 0x2f8;
-       ns16550_com2.irq     = 3;
-       ns16550_init(1, &ns16550_com2);
+        ns16550_init(0, &ns16550_com1);
+        if (ns16550_com1.io_base == 0x3f8) {
+            /* Also init com2 for Tiger4. */
+            ns16550_com2.io_base = 0x2f8;
+            ns16550_com2.irq     = 3;
+            ns16550_init(1, &ns16550_com2);
+        }
     }
     serial_init_preirq();