Fix smartthings doing blocking I/O in the event loop to import platforms (#113382)

homeassistant/components/smartthings/__init__.py

@@ -27,6 +27,7 @@ from homeassistant.helpers.dispatcher import (
 from homeassistant.helpers.entity import Entity
 from homeassistant.helpers.event import async_track_time_interval
 from homeassistant.helpers.typing import ConfigType
+from homeassistant.loader import async_get_loaded_integration
 
 from .config_flow import SmartThingsFlowHandler  # noqa: F401
 from .const import (
@@ -104,6 +105,12 @@ async def async_setup_entry(hass: HomeAssistant, entry: ConfigEntry) -> bool:
 
     api = SmartThings(async_get_clientsession(hass), entry.data[CONF_ACCESS_TOKEN])
 
+    # Ensure platform modules are loaded since the DeviceBroker will
+    # import them below and we want them to be cached ahead of time
+    # so the integration does not do blocking I/O in the event loop
+    # to import the modules.
+    await async_get_loaded_integration(hass, DOMAIN).async_get_platforms(PLATFORMS)
+
     remove_entry = False
     try:
         # See if the app is already setup. This occurs when there are