hvc_console: stop HVC console while xmon is running

arch/ppc64/xmon/xmon.c

@@ -33,7 +33,7 @@
 #define skipbl	xmon_skipbl
 
 #ifdef CONFIG_SMP
-static unsigned long cpus_in_xmon = 0;
+unsigned long cpus_in_xmon = 0;
 static unsigned long got_xmon = 0;
 static volatile int take_xmon = -1;
 #endif /* CONFIG_SMP */

drivers/char/hvc_console.c

@@ -227,6 +227,8 @@ static void hvc_poll(int index)
 	spin_unlock_irqrestore(&hp->lock, flags);
 }
 
+extern unsigned long cpus_in_xmon;
+
 int khvcd(void *unused)
 {
 	int i;
@@ -237,8 +239,10 @@ int khvcd(void *unused)
 	sigfillset(&current->blocked);
 
 	for (;;) {
+		if (!cpus_in_xmon) {
 			for (i = 0; i < MAX_NR_HVC_CONSOLES; ++i)
 				hvc_poll(i);
+		}
 		set_current_state(TASK_INTERRUPTIBLE);
 		schedule_timeout(TIMEOUT);
 	}