IP22ZILOG: fix lockup and sysrq

 - fix lockup when switching from early console to real console
 - make sysrq reliable
 - fix panic, if sysrq is issued before console is opened

Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Acked-by: Ralf Baechle <ralf@linux-mips.org>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/include/linux/serial_core.h b/include/linux/serial_core.h
index 6a5203f..9963f81 100644
--- a/include/linux/serial_core.h
+++ b/include/linux/serial_core.h
@@ -437,7 +437,7 @@
 #ifdef SUPPORT_SYSRQ
 	if (port->sysrq) {
 		if (ch && time_before(jiffies, port->sysrq)) {
-			handle_sysrq(ch, port->info->tty);
+			handle_sysrq(ch, port->info ? port->info->tty : NULL);
 			port->sysrq = 0;
 			return 1;
 		}