From 2a637b2bfb82ef0c4df85b45f531de131d6e5d7a Mon Sep 17 00:00:00 2001
From: Thadeu Lima de Souza Cascardo <cascardo@holoscopio.com>
Date: Thu, 20 May 2010 18:37:48 -0400
Subject: [PATCH 1/1] Use timer to print our default greeting.

---
 hellochar.c | 19 +++++++++++++------
 1 file changed, 13 insertions(+), 6 deletions(-)

diff --git a/hellochar.c b/hellochar.c
index 3830a47..938b32f 100644
--- a/hellochar.c
+++ b/hellochar.c
@@ -21,7 +21,7 @@
 #include <linux/cdev.h>
 #include <linux/slab.h>
 #include <linux/spinlock.h>
-#include <linux/sched.h>
+#include <linux/timer.h>
 
 MODULE_LICENSE("GPL");
 
@@ -36,14 +36,21 @@ static int hello_open(struct inode *ino, struct file *fp)
 	return 0;
 }
 
+static void hello_world(unsigned long greeting)
+{
+	printk(KERN_INFO "%s", (char *) greeting);
+}
+
+static struct timer_list hello_timer;
 static ssize_t hello_read(struct file *fp, char __user *buf, size_t sz,
 	loff_t *pos)
 {
-	unsigned long timeout = 5 * HZ;
-	while (timeout > 0) {
-		set_current_state(TASK_INTERRUPTIBLE);
-		timeout = schedule_timeout(timeout);
-	}
+	printk(KERN_INFO "Adding timer...\n");
+	init_timer(&hello_timer);
+	hello_timer.expires = jiffies + 5 * HZ;
+	hello_timer.function = hello_world;
+	hello_timer.data = (unsigned long) default_greeting;
+	add_timer(&hello_timer);
 	return 0;
 }
 
-- 
2.20.1