From: Peter Zijlstra <peterz@infradead.org>
Date: Fri, 2 Sep 2011 14:41:29 +0200
Subject: printk: Add "force_early_printk" boot param to help with debugging
Git-repo: git://git.kernel.org/pub/scm/linux/kernel/git/rt/linux-rt-devel.git
Git-commit: 72af6f61d796aed1448afdd502ac0179b3eaefeb
Patch-mainline: Queued in subsystem maintainer repository
References: SLE Realtime Extension

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
Signed-off-by: Mike Galbraith <mgalbraith@suse.de>
---
 kernel/printk/printk.c |    7 +++++++
 1 file changed, 7 insertions(+)

--- a/kernel/printk/printk.c
+++ b/kernel/printk/printk.c
@@ -430,6 +430,13 @@ 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;