patch-2.4.20 linux-2.4.20/drivers/char/wdt.c

• Lines: 79
• Date: Thu Nov 28 15:53:12 2002
• Orig file: linux-2.4.19/drivers/char/wdt.c
• Orig date: Fri Aug 2 17:39:43 2002

diff -urN linux-2.4.19/drivers/char/wdt.c linux-2.4.20/drivers/char/wdt.c
@@ -28,6 +28,7 @@
  *					Parameterized timeout
  *		Tigran Aivazian	:	Restructured wdt_init() to handle failures
  *		Joel Becker	:	Added WDIOC_GET/SETTIMEOUT
+ *		Matt Domsch	:	Added nowayout module option
  */
 
 #include <linux/config.h>
@@ -52,6 +53,7 @@
 #include <linux/init.h>
 
 static unsigned long wdt_is_open;
+static int expect_close;
 
 /*
  *	You must set these - there is no sane way to probe for this board.
@@ -66,6 +68,15 @@
 
 static int wd_margin = WD_TIMO;
 
+#ifdef CONFIG_WATCHDOG_NOWAYOUT
+static int nowayout = 1;
+#else
+static int nowayout = 0;
+#endif
+
+MODULE_PARM(nowayout,"i");
+MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default=CONFIG_WATCHDOG_NOWAYOUT)");
+
 #ifndef MODULE
 
 /**
@@ -243,6 +254,20 @@
 
 	if(count)
 	{
+		if (!nowayout) {
+			size_t i;
+
+			/* In case it was set long ago */
+			expect_close = 0;
+
+			for (i = 0; i != count; i++) {
+				char c;
+				if (get_user(c, buf + i))
+					return -EFAULT;
+				if (c == 'V')
+					expect_close = 1;
+			}
+		}
 		wdt_ping();
 		return 1;
 	}
@@ -304,7 +329,7 @@
 	{
 		WDIOF_OVERHEAT|WDIOF_POWERUNDER|WDIOF_POWEROVER
 			|WDIOF_EXTERN1|WDIOF_EXTERN2|WDIOF_FANFAULT
-			|WDIOF_SETTIMEOUT,
+			|WDIOF_SETTIMEOUT|WDIOF_MAGICCLOSE,
 		1,
 		"WDT500/501"
 	};
@@ -394,10 +419,12 @@
 {
 	if(MINOR(inode->i_rdev)==WATCHDOG_MINOR)
 	{
-#ifndef CONFIG_WATCHDOG_NOWAYOUT	
-		inb_p(WDT_DC);		/* Disable counters */
-		wdt_ctr_load(2,0);	/* 0 length reset pulses now */
-#endif		
+		if (expect_close) {
+			inb_p(WDT_DC);		/* Disable counters */
+			wdt_ctr_load(2,0);	/* 0 length reset pulses now */
+		} else {
+			printk(KERN_CRIT "wdt: WDT device closed unexpectedly.  WDT will not stop!\n");
+		}
 		clear_bit(0, &wdt_is_open);
 	}
 	return 0;