--- zzzz-none-000/linux-4.1.52/drivers/char/random.c	2018-05-28 02:26:45.000000000 +0000
+++ bcm63-7530ax-731/linux-4.1.52/drivers/char/random.c	2022-03-02 11:37:12.000000000 +0000
@@ -661,7 +661,9 @@
 		if (r == &nonblocking_pool) {
 			prandom_reseed_late();
 			wake_up_interruptible(&urandom_init_wait);
+#if !defined(CONFIG_BCM_KF_SUPPRESS_DEBUG) 
 			pr_notice("random: %s pool is initialized\n", r->name);
+#endif
 		}
 	}
 
@@ -1524,6 +1526,55 @@
 	.llseek = noop_llseek,
 };
 
+/*
+ * Each time the timer fires, we expect that we got an unpredictable
+ * jump in the cycle counter. Even if the timer is running on another
+ * CPU, the timer activity will be touching the stack of the CPU that is
+ * generating entropy..
+ *
+ * Note that we don't re-arm the timer in the timer itself - we are
+ * happy to be scheduled away, since that just makes the load more
+ * complex, but we do not want the timer to keep ticking unless the
+ * entropy loop is running.
+ *
+ * So the re-arming always happens in the entropy loop itself.
+ */
+static void entropy_timer(unsigned long data)
+{
+	credit_entropy_bits(&input_pool, 1);
+}
+
+/*
+ * If we have an actual cycle counter, see if we can
+ * generate enough entropy with timing noise
+ */
+static void try_to_generate_entropy(void)
+{
+	struct {
+		unsigned long now;
+		struct timer_list timer;
+	} stack;
+
+	stack.now = random_get_entropy();
+
+	/* Slow counter - or none. Don't even bother */
+	if (stack.now == random_get_entropy())
+		return;
+
+	setup_timer_on_stack(&stack.timer, entropy_timer, 0);
+	while (!nonblocking_pool.initialized) {
+		if (!timer_pending(&stack.timer))
+			mod_timer(&stack.timer, jiffies+1);
+		mix_pool_bytes(&input_pool, &stack.now, sizeof(stack.now));
+		schedule();
+		stack.now = random_get_entropy();
+	}
+
+	del_timer_sync(&stack.timer);
+	destroy_timer_on_stack(&stack.timer);
+	mix_pool_bytes(&input_pool, &stack.now, sizeof(stack.now));
+}
+
 SYSCALL_DEFINE3(getrandom, char __user *, buf, size_t, count,
 		unsigned int, flags)
 {
@@ -1539,6 +1590,9 @@
 	if (unlikely(nonblocking_pool.initialized == 0)) {
 		if (flags & GRND_NONBLOCK)
 			return -EAGAIN;
+
+		try_to_generate_entropy();
+
 		wait_event_interruptible(urandom_init_wait,
 					 nonblocking_pool.initialized);
 		if (signal_pending(current))