diff --git a/README b/README
index a565748e43..ad13092bbb 100644
--- a/README
+++ b/README
@@ -747,6 +747,15 @@ The following options need to be configured:
 		SoC, then define this variable and provide board
 		specific code for the "hw_watchdog_reset" function.
 
+		CONFIG_SYS_WATCHDOG_FREQ
+		Some platforms automatically call WATCHDOG_RESET()
+		from the timer interrupt handler every
+		CONFIG_SYS_WATCHDOG_FREQ interrupts. If not set by the
+		board configuration file, a default of CONFIG_SYS_HZ/2
+		(i.e. 500) is used. Setting CONFIG_SYS_WATCHDOG_FREQ
+		to 0 disables calling WATCHDOG_RESET() from the timer
+		interrupt.
+
 - Real-Time Clock:
 
 		When CONFIG_CMD_DATE is selected, the type of the RTC
diff --git a/arch/m68k/lib/time.c b/arch/m68k/lib/time.c
index cbe29e72a8..ebb2ac54db 100644
--- a/arch/m68k/lib/time.c
+++ b/arch/m68k/lib/time.c
@@ -71,7 +71,7 @@ void dtimer_interrupt(void *not_used)
 		timestamp++;
 
 		#if defined(CONFIG_WATCHDOG) || defined (CONFIG_HW_WATCHDOG)
-		if ((timestamp % (CONFIG_SYS_WATCHDOG_FREQ)) == 0) {
+		if (CONFIG_SYS_WATCHDOG_FREQ && (timestamp % (CONFIG_SYS_WATCHDOG_FREQ)) == 0) {
 			WATCHDOG_RESET ();
 		}
 		#endif    /* CONFIG_WATCHDOG || CONFIG_HW_WATCHDOG */
diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig
index 6a2e88fed2..133447648c 100644
--- a/arch/powerpc/Kconfig
+++ b/arch/powerpc/Kconfig
@@ -49,5 +49,6 @@ source "arch/powerpc/cpu/mpc83xx/Kconfig"
 source "arch/powerpc/cpu/mpc85xx/Kconfig"
 source "arch/powerpc/cpu/mpc86xx/Kconfig"
 source "arch/powerpc/cpu/mpc8xx/Kconfig"
+source "arch/powerpc/lib/Kconfig"
 
 endmenu
diff --git a/arch/powerpc/lib/Kconfig b/arch/powerpc/lib/Kconfig
new file mode 100644
index 0000000000..b30b5edf7c
--- /dev/null
+++ b/arch/powerpc/lib/Kconfig
@@ -0,0 +1,9 @@
+config CACHE_FLUSH_WATCHDOG_THRESHOLD
+	int "Bytes to flush between WATCHDOG_RESET calls"
+	default 0
+	help
+	  The flush_cache() function periodically, and by default for
+	  every cache line, calls WATCHDOG_RESET(). When flushing a
+	  large area, that may add a significant amount of
+	  overhead. This option allows you to set a threshold for how
+	  many bytes to flush between each WATCHDOG_RESET call.
diff --git a/arch/powerpc/lib/cache.c b/arch/powerpc/lib/cache.c
index 3c3c470bbb..19162511ce 100644
--- a/arch/powerpc/lib/cache.c
+++ b/arch/powerpc/lib/cache.c
@@ -9,10 +9,20 @@
 #include <asm/cache.h>
 #include <watchdog.h>
 
+static ulong maybe_watchdog_reset(ulong flushed)
+{
+	flushed += CONFIG_SYS_CACHELINE_SIZE;
+	if (flushed >= CONFIG_CACHE_FLUSH_WATCHDOG_THRESHOLD) {
+		WATCHDOG_RESET();
+		flushed = 0;
+	}
+	return flushed;
+}
+
 void flush_cache(ulong start_addr, ulong size)
 {
-#ifndef CONFIG_5xx
 	ulong addr, start, end;
+	ulong flushed = 0;
 
 	start = start_addr & ~(CONFIG_SYS_CACHELINE_SIZE - 1);
 	end = start_addr + size - 1;
@@ -20,7 +30,7 @@ void flush_cache(ulong start_addr, ulong size)
 	for (addr = start; (addr <= end) && (addr >= start);
 			addr += CONFIG_SYS_CACHELINE_SIZE) {
 		asm volatile("dcbst 0,%0" : : "r" (addr) : "memory");
-		WATCHDOG_RESET();
+		flushed = maybe_watchdog_reset(flushed);
 	}
 	/* wait for all dcbst to complete on bus */
 	asm volatile("sync" : : : "memory");
@@ -28,10 +38,9 @@ void flush_cache(ulong start_addr, ulong size)
 	for (addr = start; (addr <= end) && (addr >= start);
 			addr += CONFIG_SYS_CACHELINE_SIZE) {
 		asm volatile("icbi 0,%0" : : "r" (addr) : "memory");
-		WATCHDOG_RESET();
+		flushed = maybe_watchdog_reset(flushed);
 	}
 	asm volatile("sync" : : : "memory");
 	/* flush prefetch queue */
 	asm volatile("isync" : : : "memory");
-#endif
 }
diff --git a/arch/powerpc/lib/interrupts.c b/arch/powerpc/lib/interrupts.c
index 73f270002c..5ba4cd0c13 100644
--- a/arch/powerpc/lib/interrupts.c
+++ b/arch/powerpc/lib/interrupts.c
@@ -80,7 +80,7 @@ void timer_interrupt(struct pt_regs *regs)
 	timestamp++;
 
 #if defined(CONFIG_WATCHDOG) || defined (CONFIG_HW_WATCHDOG)
-	if ((timestamp % (CONFIG_SYS_WATCHDOG_FREQ)) == 0)
+	if (CONFIG_SYS_WATCHDOG_FREQ && (timestamp % (CONFIG_SYS_WATCHDOG_FREQ)) == 0)
 		WATCHDOG_RESET ();
 #endif    /* CONFIG_WATCHDOG || CONFIG_HW_WATCHDOG */
 
diff --git a/drivers/timer/mpc83xx_timer.c b/drivers/timer/mpc83xx_timer.c
index f4f6e90387..952293195f 100644
--- a/drivers/timer/mpc83xx_timer.c
+++ b/drivers/timer/mpc83xx_timer.c
@@ -20,6 +20,10 @@
 
 DECLARE_GLOBAL_DATA_PTR;
 
+#ifndef CONFIG_SYS_WATCHDOG_FREQ
+#define CONFIG_SYS_WATCHDOG_FREQ (CONFIG_SYS_HZ / 2)
+#endif
+
 /**
  * struct mpc83xx_timer_priv - Private data structure for MPC83xx timer driver
  * @decrementer_count: Value to which the decrementer register should be re-set
@@ -171,7 +175,7 @@ void timer_interrupt(struct pt_regs *regs)
 	priv->timestamp++;
 
 #if defined(CONFIG_WATCHDOG) || defined(CONFIG_HW_WATCHDOG)
-	if ((timestamp % (CONFIG_SYS_WATCHDOG_FREQ)) == 0)
+	if (CONFIG_SYS_WATCHDOG_FREQ && (priv->timestamp % (CONFIG_SYS_WATCHDOG_FREQ)) == 0)
 		WATCHDOG_RESET();
 #endif    /* CONFIG_WATCHDOG || CONFIG_HW_WATCHDOG */
 
diff --git a/drivers/watchdog/wdt-uclass.c b/drivers/watchdog/wdt-uclass.c
index 0603ffbd36..2687135296 100644
--- a/drivers/watchdog/wdt-uclass.c
+++ b/drivers/watchdog/wdt-uclass.c
@@ -148,7 +148,7 @@ void watchdog_reset(void)
 
 	/* Do not reset the watchdog too often */
 	now = get_timer(0);
-	if (time_after(now, next_reset)) {
+	if (time_after_eq(now, next_reset)) {
 		next_reset = now + reset_period;
 		wdt_reset(gd->watchdog_dev);
 	}