From 9ff06c67352df2ff8e7f4ef5bf0b57a713f47db0 Mon Sep 17 00:00:00 2001
From: Ayke van Laethem <aykevanlaethem@gmail.com>
Date: Wed, 1 Oct 2025 11:56:18 +0200
Subject: [PATCH] runtime: fix sleep duration for long sleeps

Long sleep durations weren't implemented correctly, by simply casting to
a smaller number of bits. What we want is a saturating downcast, which
is what I've used here instead.

This should fix https://github.com/tinygo-org/tinygo/issues/3356.
---
 src/runtime/runtime_atsamd21.go | 3 +++
 src/runtime/runtime_atsamd51.go | 3 +++
 src/runtime/runtime_nrf.go      | 3 +++
 src/runtime/runtime_nrf52840.go | 3 +++
 4 files changed, 12 insertions(+)

diff --git a/src/runtime/runtime_atsamd21.go b/src/runtime/runtime_atsamd21.go
index e0aeb08690..52bedf739f 100644
--- a/src/runtime/runtime_atsamd21.go
+++ b/src/runtime/runtime_atsamd21.go
@@ -273,6 +273,9 @@ func nanosecondsToTicks(ns int64) timeUnit {
 func sleepTicks(d timeUnit) {
 	for d != 0 {
 		ticks := uint32(d)
+		if d > 0xffff_ffff {
+			ticks = 0xffff_ffff
+		}
 		if !timerSleep(ticks) {
 			// Bail out early to handle a non-time interrupt.
 			return
diff --git a/src/runtime/runtime_atsamd51.go b/src/runtime/runtime_atsamd51.go
index 5c8a3d8b2f..f8d46275b5 100644
--- a/src/runtime/runtime_atsamd51.go
+++ b/src/runtime/runtime_atsamd51.go
@@ -266,6 +266,9 @@ func nanosecondsToTicks(ns int64) timeUnit {
 func sleepTicks(d timeUnit) {
 	for d != 0 {
 		ticks := uint32(d)
+		if d > 0xffff_ffff {
+			ticks = 0xffff_ffff
+		}
 		if !timerSleep(ticks) {
 			return
 		}
diff --git a/src/runtime/runtime_nrf.go b/src/runtime/runtime_nrf.go
index a295b99669..5c992ec47b 100644
--- a/src/runtime/runtime_nrf.go
+++ b/src/runtime/runtime_nrf.go
@@ -78,6 +78,9 @@ func buffered() int {
 func sleepTicks(d timeUnit) {
 	for d != 0 {
 		ticks := uint32(d) & 0x7fffff // 23 bits (to be on the safe side)
+		if d > 0x7fffff {
+			ticks = 0x7fffff
+		}
 		rtc_sleep(ticks)
 		d -= timeUnit(ticks)
 	}
diff --git a/src/runtime/runtime_nrf52840.go b/src/runtime/runtime_nrf52840.go
index 4ac7314a24..3c7deb031d 100644
--- a/src/runtime/runtime_nrf52840.go
+++ b/src/runtime/runtime_nrf52840.go
@@ -81,6 +81,9 @@ func buffered() int {
 func sleepTicks(d timeUnit) {
 	for d != 0 {
 		ticks := uint32(d) & 0x7fffff // 23 bits (to be on the safe side)
+		if d > 0x7fffff {
+			ticks = 0x7fffff
+		}
 		rtc_sleep(ticks)
 		d -= timeUnit(ticks)
 	}