[PATCH 4/8] PM: suspend_block: Add debugfs file

["Arve Hjønnevåg" <arve@android.com>]

Report active and inactive suspend blockers in
/sys/kernel/debug/suspend_blockers.

Signed-off-by: Arve Hjønnevåg <arve@android.com>
---
 kernel/power/opportunistic_suspend.c |   43 +++++++++++++++++++++++++++++++++-
 1 files changed, 42 insertions(+), 1 deletions(-)

diff --git a/kernel/power/opportunistic_suspend.c b/kernel/power/opportunistic_suspend.c
index acc1651..c2dad76 100644
--- a/kernel/power/opportunistic_suspend.c
+++ b/kernel/power/opportunistic_suspend.c
@@ -17,6 +17,7 @@
 #include <linux/module.h>
 #include <linux/rtc.h>
 #include <linux/suspend.h>
+#include <linux/debugfs.h>
 
 #include "power.h"
 
@@ -138,7 +139,8 @@ EXPORT_SYMBOL(suspend_blocker_register);
 /**
  * suspend_blocker_init - Initialize a suspend blocker's name and register it.
  * @blocker: Suspend blocker to initialize.
- * @name:    The name of the suspend blocker to show in debug messages.
+ * @name:    The name of the suspend blocker to show in debug messages and
+ *	     /sys/kernel/debug/suspend_blockers.
  *
  * The suspend blocker struct and name must not be freed before calling
  * suspend_blocker_unregister().
@@ -282,3 +284,42 @@ void __init opportunistic_suspend_init(void)
 	suspend_blocker_register(&main_suspend_blocker);
 	suspend_block(&main_suspend_blocker);
 }
+
+static struct dentry *suspend_blocker_stats_dentry;
+
+static int suspend_blocker_stats_show(struct seq_file *m, void *unused)
+{
+	unsigned long irqflags;
+	struct suspend_blocker *blocker;
+
+	seq_puts(m, "name\tactive\n");
+	spin_lock_irqsave(&list_lock, irqflags);
+	list_for_each_entry(blocker, &inactive_blockers, link)
+		seq_printf(m, "\"%s\"\t0\n", blocker->name);
+	list_for_each_entry(blocker, &active_blockers, link)
+		seq_printf(m, "\"%s\"\t1\n", blocker->name);
+	spin_unlock_irqrestore(&list_lock, irqflags);
+	return 0;
+}
+
+static int suspend_blocker_stats_open(struct inode *inode, struct file *file)
+{
+	return single_open(file, suspend_blocker_stats_show, NULL);
+}
+
+static const struct file_operations suspend_blocker_stats_fops = {
+	.owner = THIS_MODULE,
+	.open = suspend_blocker_stats_open,
+	.read = seq_read,
+	.llseek = seq_lseek,
+	.release = single_release,
+};
+
+static int __init suspend_blocker_debugfs_init(void)
+{
+	suspend_blocker_stats_dentry = debugfs_create_file("suspend_blockers",
+			S_IRUGO, NULL, NULL, &suspend_blocker_stats_fops);
+	return 0;
+}
+
+postcore_initcall(suspend_blocker_debugfs_init);
-- 
1.6.5.1