Subject: printk: %27force_early_printk%27 boot param to help with debugging
From: Peter Zijlstra <peterz@infradead.org>
Date: Fri, 02 Sep 2011 14:41:29 +0200

Subject: printk: 'force_early_printk' boot param to help with debugging
From: Peter Zijlstra <a.p.zijlstra@chello.nl>
Date: Fri Sep 02 14:29:33 CEST 2011

Gives me an option to screw printk and actually see what the machine
says.

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/1314967289.1301.11.camel@twins
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/n/tip-ykb97nsfmobq44xketrxs977@git.kernel.org
---
 kernel/printk.c |    7 +++++++
 1 file changed, 7 insertions(+)

Index: linux-stable/kernel/printk.c
===================================================================
--- linux-stable.orig/kernel/printk.c
+++ linux-stable/kernel/printk.c
@@ -1255,6 +1255,13 @@ asmlinkage void early_printk(const char 
  */
 static bool __read_mostly printk_killswitch;
 
+static int __init force_early_printk_setup(char *str)
+{
+	printk_killswitch = true;
+	return 0;
+}
+early_param("force_early_printk", force_early_printk_setup);
+
 void printk_kill(void)
 {
 	printk_killswitch = true;