esp32: Pin MicroPython to core 1 again.

This follows up on #5489, where we changed the esp32 core pinning to core 0
in order to work around an issue with IDF < 4.2.0.  Now that IDF > 4.2.0 is
available, we allow pinning back to core 1, which eliminates some
problematic callback latency with WiFi enabled.

NimBLE is also pinned to core 1 - the same core as MicroPython - when using
IDF >=4.2.

ports/esp32/CMakeLists.txt

@@ -18,12 +18,22 @@ if(NOT EXISTS ${MICROPY_BOARD_DIR}/mpconfigboard.cmake)
     message(FATAL_ERROR "Invalid MICROPY_BOARD specified: ${MICROPY_BOARD}")
 endif()
 
+# Include main IDF cmake file.
+include($ENV{IDF_PATH}/tools/cmake/project.cmake)
+
 # Define the output sdkconfig so it goes in the build directory.
 set(SDKCONFIG ${CMAKE_BINARY_DIR}/sdkconfig)
 
 # Include board config; this is expected to set SDKCONFIG_DEFAULTS (among other options).
 include(${MICROPY_BOARD_DIR}/mpconfigboard.cmake)
 
+# Add sdkconfig fragments that depend on the IDF version.
+if(IDF_VERSION_MAJOR EQUAL 4 AND IDF_VERSION_MINOR LESS 2)
+    set(SDKCONFIG_DEFAULTS ${SDKCONFIG_DEFAULTS} boards/sdkconfig.nimble_core0)
+else()
+    set(SDKCONFIG_DEFAULTS ${SDKCONFIG_DEFAULTS} boards/sdkconfig.nimble_core1)
+endif()
+
 # Concatenate all sdkconfig files into a combined one for the IDF to use.
 file(WRITE ${CMAKE_BINARY_DIR}/sdkconfig.combined.in "")
 foreach(SDKCONFIG_DEFAULT ${SDKCONFIG_DEFAULTS})
@@ -33,6 +43,5 @@ endforeach()
 configure_file(${CMAKE_BINARY_DIR}/sdkconfig.combined.in ${CMAKE_BINARY_DIR}/sdkconfig.combined COPYONLY)
 set(SDKCONFIG_DEFAULTS ${CMAKE_BINARY_DIR}/sdkconfig.combined)
 
-# Include main IDF cmake file and define the project.
-include($ENV{IDF_PATH}/tools/cmake/project.cmake)
+# Define the project.
 project(micropython)

ports/esp32/boards/sdkconfig.ble

@@ -7,11 +7,3 @@ CONFIG_BTDM_CTRL_MODE_BTDM=
 CONFIG_BT_NIMBLE_ENABLED=y
 
 CONFIG_BT_NIMBLE_MAX_CONNECTIONS=4
-
-# Pin to the same core as MP.
-# 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

ports/esp32/boards/sdkconfig.nimble_core0

@@ -0,0 +1,6 @@
+# For 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

ports/esp32/boards/sdkconfig.nimble_core1

@@ -0,0 +1,6 @@
+# For IDF >=4.2, we are able to put NimBLE on core 1, and for synchronisation
+# with the ringbuffer and scheduler MP needs to be on the same core.
+# MP on core 1 prevents interference with WiFi for time sensitive operations.
+CONFIG_BT_NIMBLE_PINNED_TO_CORE_0=n
+CONFIG_BT_NIMBLE_PINNED_TO_CORE_1=y
+CONFIG_BT_NIMBLE_PINNED_TO_CORE=1

ports/esp32/mphalport.h

@@ -38,10 +38,15 @@
 #define MICROPY_PLATFORM_VERSION "IDF" IDF_VER
 
 // 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
+// Now that we have IDF 4.2.0+, we are once again able to pin to core 1
+// and avoid the Wifi/BLE timing problems on the same core.
+// Best effort here to remain backwards compatible in rare version edge cases...
+// See https://github.com/micropython/micropython/issues/5489 for history
+#if ESP_IDF_VERSION >= ESP_IDF_VERSION_VAL(4, 2, 0)
+#define MP_TASK_COREID (1)
+#else
 #define MP_TASK_COREID (0)
+#endif
 
 extern TaskHandle_t mp_main_task_handle;