Fix ESP32-S2/S3 raw-REPL paste corruption

ports/espressif/supervisor/usb.c

@@ -30,6 +30,59 @@
 #include "hal/usb_serial_jtag_ll.h"
 #endif
 
+#if CIRCUITPY_USB_DEVICE && CIRCUITPY_USB_CDC
+#include "py/ringbuf.h"
+#include "shared-bindings/microcontroller/__init__.h"
+#include "shared-module/usb_cdc/__init__.h"
+
+// tud_task() runs in the usbd task below. Reading the TinyUSB fifo from the VM
+// task could re-arm the CDC OUT endpoint while tud_task() is still copying the
+// previous packet out of it, so console input is staged in this ringbuf on the
+// usbd task. Both tasks use it, so every access runs with interrupts disabled.
+static uint8_t _cdc_rx_buf[256];
+static ringbuf_t _cdc_rx_ringbuf = { .buf = _cdc_rx_buf, .size = sizeof(_cdc_rx_buf) };
+
+void usb_cdc_rx_drain(void) {
+    if (!usb_cdc_console_enabled()) {
+        return;
+    }
+    uint8_t chunk[64];
+    while (tud_cdc_available() > 0) {
+        common_hal_mcu_disable_interrupts();
+        size_t room = ringbuf_num_empty(&_cdc_rx_ringbuf);
+        common_hal_mcu_enable_interrupts();
+        if (room == 0) {
+            return;
+        }
+        // tud_cdc_read() can wait on the TinyUSB fifo mutex, so it runs with interrupts enabled.
+        uint32_t count = tud_cdc_read(chunk, MIN(room, sizeof(chunk)));
+        common_hal_mcu_disable_interrupts();
+        ringbuf_put_n(&_cdc_rx_ringbuf, chunk, count);
+        common_hal_mcu_enable_interrupts();
+    }
+}
+
+size_t usb_cdc_rx_read(uint8_t *data, size_t len) {
+    common_hal_mcu_disable_interrupts();
+    size_t count = ringbuf_get_n(&_cdc_rx_ringbuf, data, len);
+    common_hal_mcu_enable_interrupts();
+    return count;
+}
+
+size_t usb_cdc_rx_available(void) {
+    common_hal_mcu_disable_interrupts();
+    size_t count = ringbuf_num_filled(&_cdc_rx_ringbuf);
+    common_hal_mcu_enable_interrupts();
+    return count;
+}
+
+void usb_cdc_rx_clear(void) {
+    common_hal_mcu_disable_interrupts();
+    ringbuf_clear(&_cdc_rx_ringbuf);
+    common_hal_mcu_enable_interrupts();
+}
+#endif // CIRCUITPY_USB_DEVICE && CIRCUITPY_USB_CDC
+
 #if CIRCUITPY_USB_DEVICE
 #ifdef CFG_TUSB_DEBUG
   #define USBD_STACK_SIZE     (3 * configMINIMAL_STACK_SIZE)
@@ -51,8 +104,12 @@ static void usb_device_task(void *param) {
     while (1) {
         // tinyusb device task
         if (tusb_inited()) {
-            tud_task();
+            // Time out so console input left in the fifo while the ringbuf was full is moved in.
+            tud_task_ext(10, false);
             tud_cdc_write_flush();
+            #if CIRCUITPY_USB_CDC
+            usb_cdc_rx_drain();
+            #endif
         }
         // Yield with zero delay to switch to any other tasks at same priority.
         port_task_yield();

shared-module/usb_cdc/Serial.c

@@ -6,11 +6,25 @@
 
 #include "shared/runtime/interrupt_char.h"
 #include "shared-bindings/usb_cdc/Serial.h"
+#include "shared-module/usb_cdc/__init__.h"
 #include "shared-module/usb_cdc/Serial.h"
 #include "supervisor/shared/tick.h"
+#include "supervisor/usb.h"
 
 #include "tusb.h"
 
+// Console input goes through usb_cdc_rx_*, which a port may stage elsewhere.
+static bool _is_console(usb_cdc_serial_obj_t *self) {
+    return self->idx == 0 && usb_cdc_console_enabled();
+}
+
+static uint32_t _read(usb_cdc_serial_obj_t *self, uint8_t *data, size_t len) {
+    if (_is_console(self)) {
+        return usb_cdc_rx_read(data, len);
+    }
+    return tud_cdc_n_read(self->idx, data, len);
+}
+
 size_t common_hal_usb_cdc_serial_read(usb_cdc_serial_obj_t *self, uint8_t *data, size_t len, int *errcode) {
 
     const bool wait_forever = self->timeout < 0.0f;
@@ -19,7 +33,7 @@ size_t common_hal_usb_cdc_serial_read(usb_cdc_serial_obj_t *self, uint8_t *data,
     // Read up to len bytes immediately.
     // The number of bytes read will not be larger than what is already in the TinyUSB FIFO.
     uint32_t total_num_read = 0;
-    total_num_read = tud_cdc_n_read(self->idx, data, len);
+    total_num_read = _read(self, data, len);
 
     if (wait_forever || wait_for_timeout) {
         // Continue filling the buffer past what we already read.
@@ -46,7 +60,7 @@ size_t common_hal_usb_cdc_serial_read(usb_cdc_serial_obj_t *self, uint8_t *data,
             data += num_read;
 
             // Try to read another batch of bytes.
-            num_read = tud_cdc_n_read(self->idx, data, len);
+            num_read = _read(self, data, len);
             total_num_read += num_read;
         }
     }
@@ -98,6 +112,9 @@ size_t common_hal_usb_cdc_serial_write(usb_cdc_serial_obj_t *self, const uint8_t
 }
 
 uint32_t common_hal_usb_cdc_serial_get_in_waiting(usb_cdc_serial_obj_t *self) {
+    if (_is_console(self)) {
+        return usb_cdc_rx_available();
+    }
     return tud_cdc_n_available(self->idx);
 }
 
@@ -108,6 +125,9 @@ uint32_t common_hal_usb_cdc_serial_get_out_waiting(usb_cdc_serial_obj_t *self) {
 
 void common_hal_usb_cdc_serial_reset_input_buffer(usb_cdc_serial_obj_t *self) {
     tud_cdc_n_read_flush(self->idx);
+    if (_is_console(self)) {
+        usb_cdc_rx_clear();
+    }
 }
 
 uint32_t common_hal_usb_cdc_serial_reset_output_buffer(usb_cdc_serial_obj_t *self) {

supervisor/shared/serial.c

@@ -327,8 +327,11 @@ char serial_read(void) {
         return -1;
     }
     #endif
-    #if CIRCUITPY_TINYUSB && CIRCUITPY_USB_DEVICE
-    return (char)tud_cdc_read_char();
+    #if CIRCUITPY_TINYUSB && CIRCUITPY_USB_DEVICE && CIRCUITPY_USB_CDC
+    uint8_t c;
+    if (usb_cdc_rx_read(&c, 1) == 1) {
+        return c;
+    }
     #endif
 
     return -1;
@@ -362,7 +365,7 @@ uint32_t serial_bytes_available(void) {
 
     #if CIRCUITPY_TINYUSB && CIRCUITPY_USB_DEVICE && CIRCUITPY_USB_CDC
     if (usb_cdc_console_enabled()) {
-        count += tud_cdc_available();
+        count += usb_cdc_rx_available();
     }
     #endif
 

supervisor/shared/usb/usb_device.c

@@ -149,6 +149,23 @@ bool tud_vendor_control_xfer_cb(uint8_t rhport, uint8_t stage, tusb_control_requ
 #endif // CIRCUITPY_USB_VENDOR
 
 
+#if CIRCUITPY_USB_CDC
+// Defaults: tud_task() runs on the VM task here, so the fifo is read directly.
+MP_WEAK void usb_cdc_rx_drain(void) {
+}
+
+MP_WEAK size_t usb_cdc_rx_read(uint8_t *data, size_t len) {
+    return tud_cdc_read(data, len);
+}
+
+MP_WEAK size_t usb_cdc_rx_available(void) {
+    return tud_cdc_available();
+}
+
+MP_WEAK void usb_cdc_rx_clear(void) {
+}
+#endif
+
 #if MICROPY_KBD_EXCEPTION && CIRCUITPY_USB_CDC
 
 // The CDC RX buffer impacts monitoring for ctrl-c. TinyUSB will only ask for
@@ -173,6 +190,7 @@ void tud_cdc_rx_wanted_cb(uint8_t itf, char wanted_char) {
     // Compare mp_interrupt_char with wanted_char and ignore if not matched
     if (mp_interrupt_char == wanted_char) {
         tud_cdc_n_read_flush(itf);    // flush read fifo
+        usb_cdc_rx_clear();
         mp_sched_keyboard_interrupt();
     }
 }
@@ -186,6 +204,7 @@ void tud_cdc_send_break_cb(uint8_t itf, uint16_t duration_ms) {
 
 void tud_cdc_rx_cb(uint8_t itf) {
     (void)itf;
+    usb_cdc_rx_drain();
     // Workaround for "press any key to enter REPL" response being delayed on espressif.
     // Wake main task when any key is pressed.
     port_wake_main_task();

supervisor/usb.h

@@ -19,6 +19,16 @@ void usb_background(void);
 // Schedule usb background
 void usb_background_schedule(void);
 
+// Console (CDC interface 0) input. Defaults read the TinyUSB fifo directly; a port
+// whose tud_task() runs on another task overrides them and stages input there.
+// usb_cdc_rx_drain() runs on that task, the other three on the VM task.
+// read() fills *data with up to len bytes and returns the count, available()
+// returns the pending count, both 0 when empty. clear() drops staged input only.
+void usb_cdc_rx_drain(void);
+size_t usb_cdc_rx_read(uint8_t *data, size_t len);
+size_t usb_cdc_rx_available(void);
+void usb_cdc_rx_clear(void);
+
 // Ports must call this from their particular USB IRQ handler
 void usb_irq_handler(int instance);