Optimize mqtt platform setup (#102449)

* Optimize mqtt platform setup and correct issue

* Avoid coroutine for setup entity from discovery

* Avoid extra check

* Revert string constants

* Add comment

homeassistant/components/mqtt/__init__.py

@@ -432,15 +432,8 @@ async def async_setup_entry(hass: HomeAssistant, entry: ConfigEntry) -> bool:
             ]
             await asyncio.gather(*tasks)
 
-            await asyncio.gather(
-                *(
-                    [
-                        mqtt_data.reload_handlers[component]()
-                        for component in RELOADABLE_PLATFORMS
-                        if component in mqtt_data.reload_handlers
-                    ]
-                )
-            )
+            for _, component in mqtt_data.reload_handlers.items():
+                component()
 
             # Fire event
             hass.bus.async_fire(f"event_{DOMAIN}_reloaded", context=call.context)

homeassistant/components/mqtt/mixins.py

@@ -29,7 +29,7 @@ from homeassistant.const import (
     CONF_UNIQUE_ID,
     CONF_VALUE_TEMPLATE,
 )
-from homeassistant.core import HomeAssistant, callback
+from homeassistant.core import CALLBACK_TYPE, HomeAssistant, callback
 from homeassistant.helpers import (
     config_validation as cv,
     device_registry as dr,
@@ -276,10 +276,14 @@ def async_handle_schema_error(
 async def _async_discover(
     hass: HomeAssistant,
     domain: str,
-    async_setup: partial[Coroutine[Any, Any, None]],
+    setup: partial[CALLBACK_TYPE] | None,
+    async_setup: partial[Coroutine[Any, Any, None]] | None,
     discovery_payload: MQTTDiscoveryPayload,
 ) -> None:
-    """Discover and add an MQTT entity, automation or tag."""
+    """Discover and add an MQTT entity, automation or tag.
+
+    setup is to be run in the event loop when there is nothing to be awaited.
+    """
     if not mqtt_config_entry_enabled(hass):
         _LOGGER.warning(
             (
@@ -292,7 +296,10 @@ async def _async_discover(
         return
     discovery_data = discovery_payload.discovery_data
     try:
-        await async_setup(discovery_payload)
+        if setup is not None:
+            setup(discovery_payload)
+        elif async_setup is not None:
+            await async_setup(discovery_payload)
     except vol.Invalid as err:
         discovery_hash = discovery_data[ATTR_DISCOVERY_HASH]
         clear_discovery_hash(hass, discovery_hash)
@@ -326,7 +333,7 @@ async def async_setup_non_entity_entry_helper(
             hass,
             MQTT_DISCOVERY_NEW.format(domain, "mqtt"),
             functools.partial(
-                _async_discover, hass, domain, async_setup_from_discovery
+                _async_discover, hass, domain, None, async_setup_from_discovery
             ),
         )
     )
@@ -345,7 +352,8 @@ async def async_setup_entity_entry_helper(
     """Set up entity creation dynamically through MQTT discovery."""
     mqtt_data = get_mqtt_data(hass)
 
-    async def async_setup_from_discovery(
+    @callback
+    def async_setup_from_discovery(
         discovery_payload: MQTTDiscoveryPayload,
     ) -> None:
         """Set up an MQTT entity from discovery."""
@@ -364,12 +372,13 @@ async def async_setup_entity_entry_helper(
             hass,
             MQTT_DISCOVERY_NEW.format(domain, "mqtt"),
             functools.partial(
-                _async_discover, hass, domain, async_setup_from_discovery
+                _async_discover, hass, domain, async_setup_from_discovery, None
             ),
         )
     )
 
-    async def _async_setup_entities() -> None:
+    @callback
+    def _async_setup_entities() -> None:
         """Set up MQTT items from configuration.yaml."""
         nonlocal entity_class
         mqtt_data = get_mqtt_data(hass)
@@ -433,7 +442,7 @@ async def async_setup_entity_entry_helper(
     mqtt_data.reload_schema[domain] = platform_schema_modern
     # discover manual configured MQTT items
     mqtt_data.reload_handlers[domain] = _async_setup_entities
-    await _async_setup_entities()
+    _async_setup_entities()
 
 
 def init_entity_id_from_config(

homeassistant/components/mqtt/models.py

@@ -342,9 +342,7 @@ class MqttData:
     issues: dict[str, set[str]] = field(default_factory=dict)
     last_discovery: float = 0.0
     reload_dispatchers: list[CALLBACK_TYPE] = field(default_factory=list)
-    reload_handlers: dict[str, Callable[[], Coroutine[Any, Any, None]]] = field(
-        default_factory=dict
-    )
+    reload_handlers: dict[str, CALLBACK_TYPE] = field(default_factory=dict)
     reload_schema: dict[str, vol.Schema] = field(default_factory=dict)
     state_write_requests: EntityTopicState = field(default_factory=EntityTopicState)
     subscriptions_to_restore: list[Subscription] = field(default_factory=list)