timing: Fix timeout expiration checking nearing uptime counter overflow

src/timing.c

@@ -29,5 +29,17 @@ void platform_timeout_set(platform_timeout_s *const t, uint32_t ms)
 
 bool platform_timeout_is_expired(const platform_timeout_s *const t)
 {
-	return platform_time_ms() > t->time;
+	/* Cache the current time for the whole calculation */
+	const uint32_t counter = platform_time_ms();
+	/*
+	 * Check for the tricky overflow condition and handle that properly -
+	 * when time_ms approaches UINT32_MAX and we try to set a timeout that
+	 * overflows to a low t->time value, if we simply compare with `<`, we will
+	 * erroneously consider the timeout expired for a few ms right at the start of
+	 * the valid interval. Instead, force that region of time to be considered
+	 * not expired by checking the MSb's of the two values and handling that specially.
+	 */
+	if ((counter & UINT32_C(0x80000000)) && !(t->time & UINT32_C(0x80000000)))
+		return false;
+	return counter > t->time;
 }