printk: add console_suspend module parameter

We are enabling some power features on medfield.  To test suspend-2-RAM
conveniently, we need turn on/off console_suspend_enabled frequently.

Add a module parameter, so users could change it by:
/sys/module/printk/parameters/console_suspend

Signed-off-by: Yanmin Zhang <yanmin_zhang@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 4 insertions, 0 deletions

diff --git a/kernel/printk.c b/kernel/printk.c
index e62f949ec14..6d9dedd1145 100644
--- a/kernel/printk.c
+++ b/kernel/printk.c
@@ -1111,6 +1111,10 @@ static int __init console_suspend_disable(char *str)
         return 1;
 }
 __setup("no_console_suspend", console_suspend_disable);
+module_param_named(console_suspend, console_suspend_enabled,
+                bool, S_IRUGO | S_IWUSR);
+MODULE_PARM_DESC(console_suspend, "suspend console during suspend"
+        " and hibernate operations");
 
 /**
  * suspend_console - suspend the console subsystem