printk: add module parameter ignore_loglevel to control ignore_loglevel
We are enabling some power features on medfield. To test suspend-2-RAM
conveniently, we need turn on/off ignore_loglevel frequently without
rebooting.
Add a module parameter, so users can change it by:
/sys/module/printk/parameters/ignore_loglevel
Signed-off-by: Yanmin Zhang <yanmin.zhang@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt
index 27e0488..106efe1 100644
--- a/Documentation/kernel-parameters.txt
+++ b/Documentation/kernel-parameters.txt
@@ -973,6 +973,9 @@
ignore_loglevel [KNL]
Ignore loglevel setting - this will print /all/
kernel messages to the console. Useful for debugging.
+ We also add it as printk module parameter, so users
+ could change it dynamically, usually by
+ /sys/module/printk/parameters/ignore_loglevel.
ihash_entries= [KNL]
Set number of hash buckets for inode cache.
diff --git a/kernel/printk.c b/kernel/printk.c
index b7da183..e62f949 100644
--- a/kernel/printk.c
+++ b/kernel/printk.c
@@ -532,6 +532,9 @@
}
early_param("ignore_loglevel", ignore_loglevel_setup);
+module_param_named(ignore_loglevel, ignore_loglevel, bool, S_IRUGO | S_IWUSR);
+MODULE_PARM_DESC(ignore_loglevel, "ignore loglevel setting, to"
+ "print all kernel messages to the console.");
/*
* Write out chars from start to end - 1 inclusive