1 files changed, 33 insertions, 2 deletions

diff --git a/drivers/watchdog/booke_wdt.c b/drivers/watchdog/booke_wdt.c
index d11ffb091b0..7e7ec9c35b6 100644
--- a/drivers/watchdog/booke_wdt.c
+++ b/drivers/watchdog/booke_wdt.c
@@ -85,6 +85,22 @@ static unsigned int sec_to_period(unsigned int secs)
         return 0;
 }
 
+static void __booke_wdt_set(void *data)
+{
+        u32 val;
+
+        val = mfspr(SPRN_TCR);
+        val &= ~WDTP_MASK;
+        val |= WDTP(booke_wdt_period);
+
+        mtspr(SPRN_TCR, val);
+}
+
+static void booke_wdt_set(void)
+{
+        on_each_cpu(__booke_wdt_set, NULL, 0);
+}
+
 static void __booke_wdt_ping(void *data)
 {
         mtspr(SPRN_TSR, TSR_ENW|TSR_WIS);
@@ -181,8 +197,7 @@ static long booke_wdt_ioctl(struct file *file,
 #else
                 booke_wdt_period = tmp;
 #endif
-                mtspr(SPRN_TCR, (mfspr(SPRN_TCR) & ~WDTP_MASK) |
-                                                WDTP(booke_wdt_period));
+                booke_wdt_set();
                 return 0;
         case WDIOC_GETTIMEOUT:
                 return put_user(booke_wdt_period, p);
@@ -193,8 +208,15 @@ static long booke_wdt_ioctl(struct file *file,
         return 0;
 }
 
+/* wdt_is_active stores wether or not the /dev/watchdog device is opened */
+static unsigned long wdt_is_active;
+
 static int booke_wdt_open(struct inode *inode, struct file *file)
 {
+        /* /dev/watchdog can only be opened once */
+        if (test_and_set_bit(0, &wdt_is_active))
+                return -EBUSY;
+
         spin_lock(&booke_wdt_lock);
         if (booke_wdt_enabled == 0) {
                 booke_wdt_enabled = 1;
@@ -210,8 +232,17 @@ static int booke_wdt_open(struct inode *inode, struct file *file)
 
 static int booke_wdt_release(struct inode *inode, struct file *file)
 {
+#ifndef CONFIG_WATCHDOG_NOWAYOUT
+        /* Normally, the watchdog is disabled when /dev/watchdog is closed, but
+         * if CONFIG_WATCHDOG_NOWAYOUT is defined, then it means that the
+         * watchdog should remain enabled.  So we disable it only if
+         * CONFIG_WATCHDOG_NOWAYOUT is not defined.
+         */
         on_each_cpu(__booke_wdt_disable, NULL, 0);
         booke_wdt_enabled = 0;
+#endif
+
+        clear_bit(0, &wdt_is_active);
 
         return 0;
 }