[esp32_ble_tracker] Fix missed BLE advertisements with WiFi on ESP-IDF 5.5.5 (#18356)

esphome/components/ble_device_base/__init__.py

@@ -37,7 +37,7 @@ from esphome.const import (
     CONF_INTERVAL,
     KEY_TARGET_PLATFORM,
 )
-from esphome.core import CORE, ID, KEY_CORE
+from esphome.core import CORE, ID, KEY_CORE, TimePeriod
 from esphome.types import ConfigType
 
 CODEOWNERS = ["@Bl00d-B0b"]
@@ -243,19 +243,27 @@ def validate_scan_parameters(config: ConfigType) -> ConfigType:
     return config
 
 
+# The historical scan window default shared by the trackers that do not pin
+# their own; also the fallback for esp32's conditional default.
+DEFAULT_SCAN_WINDOW = "30ms"
+
+
 def scan_parameters_schema(
     interval_default: str,
     *,
-    window_default: str = "30ms",
+    window_default: str | Callable[[], TimePeriod] = DEFAULT_SCAN_WINDOW,
 ) -> cv.All:
     """Build the scan_parameters value schema shared by all BLE trackers.
 
     interval_default and window_default are per chip (e.g. esp32 320/30 ms,
     bk72xx/rp2 100/30 ms — the reference scan rates of the respective stacks;
-    LN882H's SDK recommends 100/50 ms). The `active` option (default on) is
-    unconditional: active scanning is part of the tracker contract — every
-    current proxy client assumes it, so a passive-only tracker must not share
-    this schema.
+    LN882H's SDK recommends 100/50 ms). window_default may also be a zero-arg
+    callable evaluated per validation when the user omits the key (esp32 uses
+    this to record that the window was defaulted, so a later validation step
+    can adjust it once sibling keys are resolved). The `active` option
+    (default on) is unconditional: active scanning is part of the tracker
+    contract — every current proxy client assumes it, so a passive-only
+    tracker must not share this schema.
     """
     schema = {
         cv.Optional(CONF_DURATION, default="5min"): cv.positive_time_period_seconds,

esphome/components/esp32_ble_tracker/__init__.py

@@ -1,5 +1,7 @@
 from __future__ import annotations
 
+import copy
+from dataclasses import dataclass
 import logging
 
 from esphome import automation
@@ -8,6 +10,7 @@ from esphome.components import ble_device_base, esp32_ble, ota
 from esphome.components.const import CONF_ON_SCAN_END, CONF_SCAN_PARAMETERS, CONF_WINDOW
 from esphome.components.esp32 import (
     add_idf_sdkconfig_option,
+    idf_version,
     request_bluetooth,
     request_software_coexistence,
 )
@@ -35,10 +38,12 @@ from esphome.const import (
     CONF_SERVICE_UUID,
     CONF_TRIGGER_ID,
 )
-from esphome.core import CORE, CoroPriority, coroutine_with_priority
+from esphome.core import CORE, CoroPriority, TimePeriod, coroutine_with_priority
 from esphome.enum import StrEnum
 from esphome.types import ConfigType
 
+DOMAIN = "esp32_ble_tracker"
+
 AUTO_LOAD = ["ble_device_base", "esp32_ble"]
 DEPENDENCIES = ["esp32"]
 CODEOWNERS = ["@bdraco"]
@@ -125,10 +130,71 @@ def validate_max_connections_deprecated(config: ConfigType) -> ConfigType:
     return config
 
 
+# ESP-IDF 5.5.5 fixed a coexistence bug on the ESP32 where BLE scans ran far
+# longer than the configured window (espressif/esp-idf#18931). Before the fix,
+# the default 30 ms window in a 320 ms interval effectively scanned at a much
+# higher duty cycle than requested; with the fix, that same default only
+# listens 9.4 % of the time and misses most advertisements when wifi shares
+# the radio. Espressif recommends setting the window equal to the interval in
+# that case: the coexistence arbiter still shares the radio with wifi, and
+# BLE uses the airtime wifi does not claim.
+IDF_SCAN_WINDOW_FIX_VERSION = cv.Version(5, 5, 5)
+
+
+@dataclass
+class TrackerData:
+    """Per-run validation state, namespaced under DOMAIN in CORE.data."""
+
+    scan_window_defaulted: bool = False
+
+
+def _get_data() -> TrackerData:
+    if DOMAIN not in CORE.data:
+        CORE.data[DOMAIN] = TrackerData()
+    return CORE.data[DOMAIN]
+
+
+def _scan_window_default() -> TimePeriod:
+    """Schema default for the scan window.
+
+    Records that the user did not set a window, so _raise_defaulted_scan_window
+    can tell a defaulted 30 ms from an explicit one; the raise itself must wait
+    for the outer schema because it depends on software_coexistence, a sibling
+    key not yet resolved here.
+    """
+    _get_data().scan_window_defaulted = True
+    return cv.positive_time_period(ble_device_base.DEFAULT_SCAN_WINDOW)
+
+
+def _raise_defaulted_scan_window(config: ConfigType) -> ConfigType:
+    """Raise a defaulted scan window to the interval where that is safe.
+
+    Only when the coexistence arbiter is compiled in (software_coexistence,
+    present iff wifi is configured and not disabled by the user) and the IDF
+    honors the window strictly (>= 5.5.5); without the arbiter a full-duty
+    scan would starve wifi outright, and a user-set window is never touched.
+    Raising to the interval cannot invalidate the already-validated
+    parameters, so no re-validation is needed.
+    """
+    if (
+        _get_data().scan_window_defaulted
+        and config.get(CONF_SOFTWARE_COEXISTENCE)
+        and idf_version() >= IDF_SCAN_WINDOW_FIX_VERSION
+    ):
+        params = config[CONF_SCAN_PARAMETERS]
+        # Copy so the config dump shows a plain value instead of a YAML
+        # anchor/alias pair pointing at the interval.
+        params[CONF_WINDOW] = copy.copy(params[CONF_INTERVAL])
+    return config
+
+
 # 320 ms is the ESP-IDF reference scan interval; the shared schema also
 # tightens validation to the controller's 2.5 ms .. 10240 ms range and rejects
 # window/interval pairs that collapse to the same 0.625 ms unit count.
-SCAN_PARAMETERS_SCHEMA = ble_device_base.scan_parameters_schema("320ms")
+# The window default is conditional (see _scan_window_default above).
+SCAN_PARAMETERS_SCHEMA = ble_device_base.scan_parameters_schema(
+    "320ms", window_default=_scan_window_default
+)
 
 # Codegen helpers are owned by ble_device_base; kept under the historical names
 # here for the components that import them from this module.
@@ -183,6 +249,7 @@ CONFIG_SCHEMA = cv.All(
         }
     ).extend(cv.COMPONENT_SCHEMA),
     validate_max_connections_deprecated,
+    _raise_defaulted_scan_window,
 )