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>

diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt
index 3ddd846e3b417a10c8730ea09de29a030b1ad7be..ccfc61ad32e950bb4208d44fa222ad9ce169d4d1 100644 (file)
--- a/Documentation/kernel-parameters.txt
+++ b/Documentation/kernel-parameters.txt
@@ -1668,6 +1668,11 @@ 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,

diff --git a/kernel/printk.c b/kernel/printk.c
index 4b2be8ab869b51f61f19cf4729d82a49974f13f7..e8614885673684aad7129428e44c51b429e62789 100644 (file)
--- 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