esp32: Pin MicroPython and NimBLE tasks to core 0.

jimmo · dpgeorge · commit 311b8519af75 · 2020-09-08T12:53:24.000+10:00
MicroPython and NimBLE must be on the same core, for synchronisation of the BLE ringbuf and the MicroPython scheduler. However, in the current IDF versions (3.3 and 4.0) there are issues (see e.g. #5489) with running NimBLE on core 1. This change - pinning both tasks to core 0 - makes it possible to reliably run the BLE multitests on esp32 boards.
diff --git a/ports/esp32/boards/sdkconfig.ble b/ports/esp32/boards/sdkconfig.ble
@@ -9,9 +9,12 @@ CONFIG_BT_NIMBLE_ENABLED=y
 CONFIG_BT_NIMBLE_MAX_CONNECTIONS=4
 
 # Pin to the same core as MP.
-CONFIG_BT_NIMBLE_PINNED_TO_CORE_0=n
-CONFIG_BT_NIMBLE_PINNED_TO_CORE_1=y
-CONFIG_BT_NIMBLE_PINNED_TO_CORE=1
+# Until we move to IDF 4.2+, we need NimBLE on core 0, and for synchronisation
+# with the ringbuffer and scheduler MP needs to be on the same core.
+# See https://github.com/micropython/micropython/issues/5489
+CONFIG_BT_NIMBLE_PINNED_TO_CORE_0=y
+CONFIG_BT_NIMBLE_PINNED_TO_CORE_1=n
+CONFIG_BT_NIMBLE_PINNED_TO_CORE=0
 
 # v3.3-only (renamed in 4.0)
 CONFIG_BTDM_CONTROLLER_MODE_BLE_ONLY=y
diff --git a/ports/esp32/mphalport.h b/ports/esp32/mphalport.h
@@ -35,8 +35,11 @@
 #include "freertos/FreeRTOS.h"
 #include "freertos/task.h"
 
-// The core that the MicroPython task(s) are pinned to
-#define MP_TASK_COREID (1)
+// The core that the MicroPython task(s) are pinned to.
+// Until we move to IDF 4.2+, we need NimBLE on core 0, and for synchronisation
+// with the ringbuffer and scheduler MP needs to be on the same core.
+// See https://github.com/micropython/micropython/issues/5489
+#define MP_TASK_COREID (0)
 
 extern TaskHandle_t mp_main_task_handle;
 
