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

• Lines: 97
• Date: Thu Nov 28 15:53:12 2002
• Orig file: linux-2.4.19/drivers/char/acquirewdt.c
• Orig date: Fri Aug 2 17:39:43 2002

diff -urN linux-2.4.19/drivers/char/acquirewdt.c linux-2.4.20/drivers/char/acquirewdt.c
@@ -17,6 +17,9 @@
  *
  *	(c) Copyright 1995    Alan Cox <alan@redhat.com>
  *
+ *      14-Dec-2001 Matt Domsch <Matt_Domsch@dell.com>
+ *          Added nowayout module option to override CONFIG_WATCHDOG_NOWAYOUT
+ *          Can't add timeout - driver doesn't allow changing value
  */
 
 #include <linux/config.h>
@@ -42,6 +45,7 @@
 
 static int acq_is_open;
 static spinlock_t acq_lock;
+static int expect_close = 0;
 
 /*
  *	You must set these - there is no sane way to probe for this board.
@@ -50,8 +54,14 @@
 #define WDT_STOP 0x43
 #define WDT_START 0x443
 
-#define WD_TIMO (100*60)		/* 1 minute */
+#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)");
 
 /*
  *	Kernel methods.
@@ -72,6 +82,21 @@
 
 	if(count)
 	{
+		if (!nowayout)
+		{
+			size_t i;
+
+			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;
+			}
+		}
+
 		acq_ping();
 		return 1;
 	}
@@ -90,7 +115,7 @@
 {
 	static struct watchdog_info ident=
 	{
-		WDIOF_KEEPALIVEPING, 1, "Acquire WDT"
+		WDIOF_KEEPALIVEPING | WDIOF_MAGICCLOSE, 1, "Acquire WDT"
 	};
 	
 	switch(cmd)
@@ -126,10 +151,12 @@
 				spin_unlock(&acq_lock);
 				return -EBUSY;
 			}
+			if (nowayout) {
+				MOD_INC_USE_COUNT;
+			}
 			/*
 			 *	Activate 
 			 */
-	 
 			acq_is_open=1;
 			inb_p(WDT_START);      
 			spin_unlock(&acq_lock);
@@ -145,9 +172,14 @@
 	if(MINOR(inode->i_rdev)==WATCHDOG_MINOR)
 	{
 		spin_lock(&acq_lock);
-#ifndef CONFIG_WATCHDOG_NOWAYOUT	
-		inb_p(WDT_STOP);
-#endif		
+		if (expect_close)
+		{
+			inb_p(WDT_STOP);
+		}
+		else
+		{
+			printk(KERN_CRIT "WDT closed unexpectedly.  WDT will not stop!\n");
+		}
 		acq_is_open=0;
 		spin_unlock(&acq_lock);
 	}