From: Michael Gernoth <michael@gernoth.net>
Date: Sat, 21 May 2011 16:46:46 +0000 (+0200)
Subject: restore old state when unloading module
X-Git-Url: https://git.zerfleddert.de/cgi-bin/gitweb.cgi/ms2-fixes/commitdiff_plain/1e65c1134a5209b2d99e91e19f983d2d9cbb4352

restore old state when unloading module
---

diff --git a/MS2Debounce/assets/debounce.ko b/MS2Debounce/assets/debounce.ko
index cb1a584..06a947d 100644
Binary files a/MS2Debounce/assets/debounce.ko and b/MS2Debounce/assets/debounce.ko differ
diff --git a/debounce.c b/debounce.c
index 845adad..4006cd2 100644
--- a/debounce.c
+++ b/debounce.c
@@ -7,6 +7,9 @@
 
 static int debounce_delay = 10;
 
+static int old_delay = 0;
+static struct gpio_event_matrix_info *gpio_evmi = NULL;
+
 module_param(debounce_delay, int, S_IRUSR | S_IRGRP | S_IROTH);
 MODULE_PARM_DESC(debounce_delay, "debouncing delay (ms), default: 10");
 
@@ -24,7 +27,6 @@ static int __init debounce_init(void)
 	struct device *event_dev = NULL;
 	struct gpio_event_platform_data *gpio_epd;
 	struct gpio_event_info *gpio_ei;
-	struct gpio_event_matrix_info *gpio_evmi;
 
 	printk(KERN_INFO PREFIX "Searching for " GPIO_EVENT_DEV_NAME "...\n");
 
@@ -53,6 +55,8 @@ static int __init debounce_init(void)
 		printk(KERN_INFO PREFIX "flags: 0x%x\n", gpio_evmi->flags);
 	}
 
+	old_delay = gpio_evmi->debounce_delay.tv.nsec;
+
 	if (gpio_evmi->debounce_delay.tv.nsec != debounce_delay * NSEC_PER_MSEC) {
 		printk(KERN_INFO PREFIX "Changing debounce_delay\n");
 		gpio_evmi->debounce_delay.tv.nsec = debounce_delay * NSEC_PER_MSEC;
@@ -64,6 +68,13 @@ static int __init debounce_init(void)
 
 static void __exit debounce_exit(void)
 {
+	if (gpio_evmi) {
+		if (gpio_evmi->debounce_delay.tv.nsec != old_delay) {
+			printk(KERN_INFO PREFIX "Restoring debounce_delay\n");
+			gpio_evmi->debounce_delay.tv.nsec = old_delay;
+			printk(KERN_INFO PREFIX "debounce_delay: %u\n", gpio_evmi->debounce_delay.tv.nsec);
+		}
+	}
 }
 
 module_init(debounce_init);