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>

arch/mips/sgi-ip22/ip22-setup.c

@@ -31,25 +31,6 @@
 unsigned long sgi_gfxaddr;
 EXPORT_SYMBOL_GPL(sgi_gfxaddr);
 
-/*
- * Stop-A is originally a Sun thing that isn't standard on IP22 so to avoid
- * accidents it's disabled by default on IP22.
- *
- * FIXME: provide a mechanism to change the value of stop_a_enabled.
- */
-int stop_a_enabled;
-
-void ip22_do_break(void)
-{
-	if (!stop_a_enabled)
-		return;
-
-	printk("\n");
-	ArcEnterInteractiveMode();
-}
-
-EXPORT_SYMBOL(ip22_do_break);
-
 extern void ip22_be_init(void) __init;
 
 void __init plat_mem_setup(void)

include/asm-mips/system.h

@@ -209,8 +209,6 @@ extern void *set_except_vector(int n, void *addr);
 extern unsigned long ebase;
 extern void per_cpu_trap_init(void);
 
-extern int stop_a_enabled;
-
 /*
  * See include/asm-ia64/system.h; prevents deadlock on SMP
  * systems.

include/linux/serial_core.h

@@ -437,7 +437,7 @@ uart_handle_sysrq_char(struct uart_port *port, unsigned int ch)
 #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;
 		}