ui: fix alert disappear when no controlState is received in a frame. (#28811)

* always return alert

* don't get old alert
old-commit-hash: d9d5ce3634

selfdrive/ui/ui.h

@@ -48,38 +48,43 @@ struct Alert {
 
   static Alert get(const SubMaster &sm, uint64_t started_frame) {
     const cereal::ControlsState::Reader &cs = sm["controlsState"].getControlsState();
-    if (sm.updated("controlsState")) {
-      return {cs.getAlertText1().cStr(), cs.getAlertText2().cStr(),
+    const uint64_t controls_frame = sm.rcv_frame("controlsState");
+
+    Alert alert = {};
+    if (controls_frame >= started_frame) {  // Don't get old alert.
+      alert = {cs.getAlertText1().cStr(), cs.getAlertText2().cStr(),
                cs.getAlertType().cStr(), cs.getAlertSize(),
                cs.getAlertStatus(),
                cs.getAlertSound()};
-    } else if ((sm.frame - started_frame) > 5 * UI_FREQ) {
+    }
+
+    if (!sm.updated("controlsState") && (sm.frame - started_frame) > 5 * UI_FREQ) {
       const int CONTROLS_TIMEOUT = 5;
       const int controls_missing = (nanos_since_boot() - sm.rcv_time("controlsState")) / 1e9;
 
       // Handle controls timeout
-      if (sm.rcv_frame("controlsState") < started_frame) {
+      if (controls_frame < started_frame) {
         // car is started, but controlsState hasn't been seen at all
-        return {"openpilot Unavailable", "Waiting for controls to start",
+        alert = {"openpilot Unavailable", "Waiting for controls to start",
                  "controlsWaiting", cereal::ControlsState::AlertSize::MID,
                  cereal::ControlsState::AlertStatus::NORMAL,
                  AudibleAlert::NONE};
       } else if (controls_missing > CONTROLS_TIMEOUT && !Hardware::PC()) {
         // car is started, but controls is lagging or died
         if (cs.getEnabled() && (controls_missing - CONTROLS_TIMEOUT) < 10) {
-          return {"TAKE CONTROL IMMEDIATELY", "Controls Unresponsive",
+          alert = {"TAKE CONTROL IMMEDIATELY", "Controls Unresponsive",
                    "controlsUnresponsive", cereal::ControlsState::AlertSize::FULL,
                    cereal::ControlsState::AlertStatus::CRITICAL,
                    AudibleAlert::WARNING_IMMEDIATE};
         } else {
-          return {"Controls Unresponsive", "Reboot Device",
+          alert = {"Controls Unresponsive", "Reboot Device",
                    "controlsUnresponsivePermanent", cereal::ControlsState::AlertSize::MID,
                    cereal::ControlsState::AlertStatus::NORMAL,
                    AudibleAlert::NONE};
         }
       }
     }
-    return {};
+    return alert;
   }
 };