From: Peter Zijlstra <peterz@infradead.org>
Date: Fri, 2 Sep 2011 14:41:29 +0200
Subject: [PATCH 058/342] printk: Add "force_early_printk" boot param to help
 with debugging
Origin: https://git.kernel.org/cgit/linux/kernel/git/rt/linux-stable-rt.git/commit?id=5bc26d1775b46f51023f203f4eab5c1068cc165c

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/printk.c | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/kernel/printk/printk.c b/kernel/printk/printk.c
index 963c20ab9548..7b774743e1ac 100644
--- a/kernel/printk/printk.c
+++ b/kernel/printk/printk.c
@@ -437,6 +437,13 @@ asmlinkage void early_printk(const char *fmt, ...)
  */
 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;