Explain how to keep the executor awake

docs/pages/faq.adoc

@@ -372,3 +372,16 @@ Issues like these while implementing drivers often fall into one of the followin
 3. Some kind of hardware errata, or some hardware misconfiguration like wrong clock speeds
 4. Some issue with an interrupt handler, either enabling, disabling, or re-enabling of interrupts when necessary
 5. Some kind of async issue, like not registering wakers fully before checking flags, or not registering or pending wakers at the right time
+
+== How can I prevent the thread-mode executor from going to sleep? ==
+
+In some cases you might want to prevent the thread-mode executor from going to sleep, for example when doing so would result in current spikes that reduce analog performance.
+As a workaround, you can spawn a task that yields in a loop, preventing the executor from going to sleep. Note that this may increase power consumption.
+
+[source,rust]
+----
+#[embassy_executor::task]
+async fn idle() {
+    loop { embassy_futures::yield_now().await; }
+}
+----