From 134620f7a865b3bc9e3d56d460603592b70ede21 Mon Sep 17 00:00:00 2001
From: Yanmin Zhang <yanmin_zhang@linux.intel.com>
Date: Mon, 31 Oct 2011 17:11:27 -0700
Subject: [PATCH] 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>
---
Documentation/kernel-parameters.txt | 5 +++++
kernel/printk.c | 4 ++++
2 files changed, 9 insertions(+)
diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt
index 106efe1e2bab2..c2efe285396c4 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,
diff --git a/kernel/printk.c b/kernel/printk.c
index e62f949ec1407..6d9dedd114506 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
--
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