From 60539ea162a15d38d974ee58f7c5430c565cf0eb Mon Sep 17 00:00:00 2001
From: robert-hh <robert@hammelrath.com>
Date: Thu, 7 Jul 2022 21:19:28 +0200
Subject: [PATCH] nrf/drivers/usb: Probe for interrupt char in USB CDC task.

And ensure that the input queue is empty when scheduling the interrupt.
---
 ports/nrf/drivers/bluetooth/ble_uart.c |  2 +-
 ports/nrf/drivers/usb/usb_cdc.c        | 10 +++++++++-
 ports/nrf/modules/machine/uart.c       |  2 ++
 3 files changed, 12 insertions(+), 2 deletions(-)

diff --git a/ports/nrf/drivers/bluetooth/ble_uart.c b/ports/nrf/drivers/bluetooth/ble_uart.c
index c3712fe8c9..3020f1af62 100644
--- a/ports/nrf/drivers/bluetooth/ble_uart.c
+++ b/ports/nrf/drivers/bluetooth/ble_uart.c
@@ -193,9 +193,9 @@ STATIC void gatts_event_handler(mp_obj_t self_in, uint16_t event_id, uint16_t at
             for (uint16_t i = 0; i < length; i++) {
                 #if MICROPY_KBD_EXCEPTION
                 if (data[i] == mp_interrupt_char) {
-                    mp_sched_keyboard_interrupt();
                     m_rx_ring_buffer.start = 0;
                     m_rx_ring_buffer.end = 0;
+                    mp_sched_keyboard_interrupt();
                 } else
                 #endif
                 {
diff --git a/ports/nrf/drivers/usb/usb_cdc.c b/ports/nrf/drivers/usb/usb_cdc.c
index a1d411a256..eda933b89f 100644
--- a/ports/nrf/drivers/usb/usb_cdc.c
+++ b/ports/nrf/drivers/usb/usb_cdc.c
@@ -35,6 +35,8 @@
 #include "nrfx_uart.h"
 #include "py/ringbuf.h"
 #include "py/stream.h"
+#include "py/runtime.h"
+#include "shared/runtime/interrupt_char.h"
 
 #ifdef BLUETOOTH_SD
 #include "nrf_sdm.h"
@@ -127,7 +129,13 @@ static void cdc_task(void)
             int c;
             uint32_t count = tud_cdc_read(&c, 1);
             (void)count;
-            ringbuf_put((ringbuf_t*)&rx_ringbuf, c);
+            if (c == mp_interrupt_char) {
+                rx_ringbuf.iget = 0;
+                rx_ringbuf.iput = 0;
+                mp_sched_keyboard_interrupt();
+            } else {
+                ringbuf_put((ringbuf_t*)&rx_ringbuf, c);
+            }
         }
 
         int chars = 0;
diff --git a/ports/nrf/modules/machine/uart.c b/ports/nrf/modules/machine/uart.c
index 2cc421aa1f..e8c82e57dd 100644
--- a/ports/nrf/modules/machine/uart.c
+++ b/ports/nrf/modules/machine/uart.c
@@ -128,6 +128,8 @@ STATIC void uart_event_handler(nrfx_uart_event_t const *p_event, void *p_context
         nrfx_uart_rx(self->p_uart, &self->buf->rx_buf[0], 1);
         #if !MICROPY_PY_BLE_NUS && MICROPY_KBD_EXCEPTION
         if (chr == mp_interrupt_char) {
+            self->buf->rx_ringbuf.iget = 0;
+            self->buf->rx_ringbuf.iput = 0;
             mp_sched_keyboard_interrupt();
         } else
         #endif