esp32/esp32_rmt: Call rmt_driver_install directly if running on core 1.

Signed-off-by: Damien George <damien@micropython.org>

ports/esp32/esp32_rmt.c

@@ -60,16 +60,18 @@ typedef struct _esp32_rmt_obj_t {
     bool loop_en;
 } esp32_rmt_obj_t;
 
+// Current channel used for machine.bitstream, in the machine_bitstream_high_low_rmt
+// implementation.  A value of -1 means do not use RMT.
+int8_t esp32_rmt_bitstream_channel_id = RMT_CHANNEL_MAX - 1;
+
+#if MP_TASK_COREID == 0
+
 typedef struct _rmt_install_state_t {
     SemaphoreHandle_t handle;
     uint8_t channel_id;
     esp_err_t ret;
 } rmt_install_state_t;
 
-// Current channel used for machine.bitstream, in the machine_bitstream_high_low_rmt
-// implementation.  A value of -1 means do not use RMT.
-int8_t esp32_rmt_bitstream_channel_id = RMT_CHANNEL_MAX - 1;
-
 STATIC void rmt_install_task(void *pvParameter) {
     rmt_install_state_t *state = pvParameter;
     state->ret = rmt_driver_install(state->channel_id, 0, 0);
@@ -92,6 +94,16 @@ esp_err_t rmt_driver_install_core1(uint8_t channel_id) {
     return state.ret;
 }
 
+#else
+
+// MicroPython runs on core 1, so we can call the RMT installer directly and its
+// interrupt handler will also run on core 1.
+esp_err_t rmt_driver_install_core1(uint8_t channel_id) {
+    return rmt_driver_install(channel_id, 0, 0);
+}
+
+#endif
+
 STATIC mp_obj_t esp32_rmt_make_new(const mp_obj_type_t *type, size_t n_args, size_t n_kw, const mp_obj_t *all_args) {
     static const mp_arg_t allowed_args[] = {
         { MP_QSTR_id,        MP_ARG_REQUIRED | MP_ARG_INT, {.u_int = -1} },