fix(radio): update radio_conf.rx_when_idle in set_link_mode

OpenThread doesn't call otPlatRadioSetRxOnWhenIdle callback, so the
radio config was never updated when link mode changed. This caused
the ESP radio driver to keep rx_when_idle: false even when the device
should stay awake to receive unsolicited messages.

Now set_link_mode directly updates radio_conf.rx_when_idle to match
the requested link mode, ensuring the ESP radio driver configuration
stays in sync.

Co-Authored-By: Claude <[email protected]>
Signed-off-by: Aleksei Sviridkin <[email protected]>

Author: lexfrei

openthread/src/lib.rs

@@ -443,6 +443,18 @@ impl<'a> OpenThread<'a> {
         let mut ot = self.activate();
         let state = ot.state();
 
+        // Update radio config rx_when_idle to match link mode.
+        // OpenThread doesn't call otPlatRadioSetRxOnWhenIdle, so we must
+        // update the radio config directly here to ensure the ESP radio
+        // driver keeps the radio awake when needed.
+        if state.ot.radio_conf.rx_when_idle != rx_on_when_idle {
+            info!(
+                "Updating radio config rx_when_idle: {} -> {}",
+                state.ot.radio_conf.rx_when_idle, rx_on_when_idle
+            );
+            state.ot.radio_conf.rx_when_idle = rx_on_when_idle;
+        }
+
         let mode = otLinkModeConfig {
             _bitfield_align_1: [],
             _bitfield_1: otLinkModeConfig::new_bitfield_1(