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, 5 insertions, 0 deletions

diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt
index 106efe1e2bab..c2efe285396c 100644
--- a/Documentation/kernel-parameters.txt
+++ b/Documentation/kernel-parameters.txt
@@ -1669,6 +1669,11 @@ bytes respectively. Such letter suffixes can also be entirely omitted.
                         debugging driver suspend/resume hooks).  This may
                         not work reliably with all consoles, but is known
                         to work with serial and VGA consoles.
+                        To facilitate more flexible debugging, we also add
+                        console_suspend, a printk module parameter to control
+                        it. Users could use console_suspend (usually
+                        /sys/module/printk/parameters/console_suspend) to
+                        turn on/off it dynamically.
 
         noaliencache    [MM, NUMA, SLAB] Disables the allocation of alien
                         caches in the slab allocator.  Saves per-node memory,