Remove txbuf in favor of fifo.

Fifo incurs a second copy into a USB buffer but this ensures the
correct USB buffer alignment. Some LPC chips require 64 byte
alignment that txbuf couldn't do.

.travis.yml

@@ -19,4 +19,3 @@ before_script:
 script:
   - make -j2 -C examples/device/cdc_msc_hid BOARD=metro_m0_express
   - make -j2 -C examples/device/cdc_msc_hid BOARD=metro_m4_express
-  - cd tests/common && make

src/class/midi/midi_device.c

@@ -46,7 +46,6 @@
 //--------------------------------------------------------------------+
 #include "midi_device.h"
 #include "class/audio/audio.h"
-#include "common/tusb_txbuf.h"
 #include "device/usbd_pvt.h"
 
 //--------------------------------------------------------------------+
@@ -60,18 +59,15 @@ typedef struct
 
   // FIFO
   tu_fifo_t rx_ff;
+  tu_fifo_t tx_ff;
   uint8_t rx_ff_buf[CFG_TUD_MIDI_RX_BUFSIZE];
-  osal_mutex_def_t rx_ff_mutex;
+  uint8_t tx_ff_buf[CFG_TUD_MIDI_TX_BUFSIZE];
 
-  #if CFG_TUD_MIDI_TX_BUFSIZE % CFG_TUD_MIDI_EPSIZE != 0
-  #error "TX buffer size must be multiple of endpoint size."
+  #if CFG_FIFO_MUTEX
+  osal_mutex_def_t rx_ff_mutex;
+  osal_mutex_def_t tx_ff_mutex;
   #endif
 
-  // This is a ring buffer that aligns to word boundaries so that it can be transferred directly to
-  // the USB peripheral. There are three states to the data: free, transmitting and pending.
-  CFG_TUSB_MEM_ALIGN uint8_t raw_tx_buffer[CFG_TUD_MIDI_TX_BUFSIZE];
-  tu_txbuf_t txbuf;
-
   // We need to pack messages into words before queueing their transmission so buffer across write
   // calls.
   uint8_t message_buffer[4];
@@ -80,6 +76,7 @@ typedef struct
 
   // Endpoint Transfer buffer
   CFG_TUSB_MEM_ALIGN uint8_t epout_buf[CFG_TUD_MIDI_EPSIZE];
+  CFG_TUSB_MEM_ALIGN uint8_t epin_buf[CFG_TUD_MIDI_EPSIZE];
 
 } midid_interface_t;
 
@@ -147,6 +144,19 @@ void midi_rx_done_cb(midid_interface_t* midi, uint8_t const* buffer, uint32_t bu
 // WRITE API
 //--------------------------------------------------------------------+
 
+static bool maybe_transmit(midid_interface_t* midi, uint8_t itf_index)
+{
+    TU_VERIFY( !dcd_edpt_busy(TUD_OPT_RHPORT, midi->ep_in) ); // skip if previous transfer not complete
+
+    uint16_t count = tu_fifo_read_n(&midi->tx_ff, midi->epin_buf, CFG_TUD_MIDI_EPSIZE);
+    if (count > 0)
+    {
+      TU_VERIFY( tud_midi_n_connected(itf_index) ); // fifo is empty if not connected
+      TU_ASSERT( dcd_edpt_xfer(TUD_OPT_RHPORT, midi->ep_in, midi->epin_buf, count) );
+    }
+    return true;
+}
+
 uint32_t tud_midi_n_write(uint8_t itf, uint8_t jack_id, uint8_t const* buffer, uint32_t bufsize)
 {
   midid_interface_t* midi = &_midid_itf[itf];
@@ -204,11 +214,16 @@ uint32_t tud_midi_n_write(uint8_t itf, uint8_t jack_id, uint8_t const* buffer, u
     }
 
     if (midi->message_buffer_length == midi->message_target_length) {
-        tu_txbuf_write_n(&midi->txbuf, midi->message_buffer, 4);
+        uint16_t written = tu_fifo_write_n(&midi->tx_ff, midi->message_buffer, 4);
+        if (written < 4) {
+            TU_ASSERT( written == 0 );
+            break;
+        }
         midi->message_buffer_length = 0;
     }
     i++;
   }
+  maybe_transmit(midi, itf);
 
   return i;
 }
@@ -226,11 +241,11 @@ void midid_init(void)
 
     // config fifo
     tu_fifo_config(&midi->rx_ff, midi->rx_ff_buf, CFG_TUD_MIDI_RX_BUFSIZE, 1, true);
+    tu_fifo_config(&midi->tx_ff, midi->tx_ff_buf, CFG_TUD_MIDI_TX_BUFSIZE, 1, true);
     #if CFG_FIFO_MUTEX
     tu_fifo_config_mutex(&midi->rx_ff, osal_mutex_create(&midi->rx_ff_mutex));
+    tu_fifo_config_mutex(&midi->tx_ff, osal_mutex_create(&midi->tx_ff_mutex));
     #endif
-
-    tu_txbuf_config(&midi->txbuf, midi->raw_tx_buffer, CFG_TUD_MIDI_TX_BUFSIZE, dcd_edpt_xfer);
   }
 }
 
@@ -243,7 +258,7 @@ void midid_reset(uint8_t rhport)
     midid_interface_t* midi = &_midid_itf[i];
     tu_memclr(midi, ITF_MEM_RESET_SIZE);
     tu_fifo_clear(&midi->rx_ff);
-    tu_txbuf_clear(&midi->txbuf);
+    tu_fifo_clear(&midi->tx_ff);
   }
 }
 
@@ -289,7 +304,6 @@ bool midid_open(uint8_t rhport, tusb_desc_interface_t const * p_interface_desc,
         uint8_t ep_addr = ((tusb_desc_endpoint_t const *) p_desc)->bEndpointAddress;
         if (tu_edpt_dir(ep_addr) == TUSB_DIR_IN) {
             p_midi->ep_in = ep_addr;
-            tu_txbuf_set_ep_addr(&p_midi->txbuf, ep_addr);
         } else {
             p_midi->ep_out = ep_addr;
         }
@@ -335,7 +349,7 @@ bool midid_xfer_cb(uint8_t rhport, uint8_t edpt_addr, xfer_result_t result, uint
     // prepare for next
     TU_ASSERT( dcd_edpt_xfer(rhport, p_midi->ep_out, p_midi->epout_buf, CFG_TUD_MIDI_EPSIZE), false );
   } else if ( edpt_addr == p_midi->ep_in ) {
-    tu_txbuf_transmit_done_cb(&p_midi->txbuf, xferred_bytes);
+    maybe_transmit(p_midi, itf);
   }
 
   // nothing to do with in and notif endpoint

src/common/tusb_txbuf.c

@@ -1,159 +0,0 @@
-/**************************************************************************/
-/*!
-    @file     tusb_txbuf.c
-    @author   Scott Shawcroft
-
-    @section LICENSE
-
-    Software License Agreement (BSD License)
-
-    Copyright (c) 2018, Scott Shawcroft
-    All rights reserved.
-
-    Redistribution and use in source and binary forms, with or without
-    modification, are permitted provided that the following conditions are met:
-    1. Redistributions of source code must retain the above copyright
-    notice, this list of conditions and the following disclaimer.
-    2. Redistributions in binary form must reproduce the above copyright
-    notice, this list of conditions and the following disclaimer in the
-    documentation and/or other materials provided with the distribution.
-    3. Neither the name of the copyright holders nor the
-    names of its contributors may be used to endorse or promote products
-    derived from this software without specific prior written permission.
-
-    THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS ''AS IS'' AND ANY
-    EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
-    WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
-    DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER BE LIABLE FOR ANY
-    DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
-    INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
-    LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION HOWEVER CAUSED AND
-    ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
-    INCLUDING NEGLIGENCE OR OTHERWISE ARISING IN ANY WAY OUT OF THE USE OF THIS
-    SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
-
- This file is part of the tinyusb stack.
- */
-/**************************************************************************/
-#include <stdio.h>
-#include <string.h>
-
-#include "tusb_txbuf.h"
-
-bool tu_txbuf_config(tu_txbuf_t *txbuf, uint8_t* buffer, uint16_t buffer_length, edpt_xfer xfer)
-{
-  txbuf->buffer = (uint8_t*) buffer;
-  txbuf->buf_len = buffer_length;
-  txbuf->first_free = 0;
-  txbuf->pending_count = 0;
-  txbuf->transmitting_count = 0;
-  txbuf->xfer = xfer;
-  txbuf->padding = 0;
-
-  return true;
-}
-
-uint16_t maybe_transmit(tu_txbuf_t* buf) {
-    if (buf->transmitting_count > 0 || buf->pending_count == 0) {
-        return 0;
-    }
-    buf->transmitting_count = buf->pending_count;
-    uint16_t transmit_start_index;
-    uint8_t over_aligned = 0;
-    // The pending zone wraps back to the end so we must do two transfers.
-    if (buf->pending_count > buf->first_free) {
-        buf->transmitting_count -= buf->first_free;
-        transmit_start_index = buf->buf_len - buf->transmitting_count;
-    } else {
-        transmit_start_index = buf->first_free - buf->transmitting_count;
-
-        // We are transmitting up to first free so ensure it's word aligned for the next transmit.
-        over_aligned = buf->first_free % sizeof(uint32_t);
-        buf->padding = sizeof(uint32_t) - over_aligned;
-        if (over_aligned != 0) {
-            buf->first_free = (buf->first_free + buf->padding) % buf->buf_len;
-        }
-    }
-    buf->pending_count -= buf->transmitting_count;
-
-    uint8_t* tx_start = buf->buffer + transmit_start_index;
-    if (!buf->xfer(0, buf->ep_addr, tx_start, buf->transmitting_count)) {
-        return 0;
-    }
-    return buf->transmitting_count;
-}
-
-uint32_t tu_txbuf_transmit_done_cb(tu_txbuf_t* buf, uint32_t bufsize) {
-    buf->transmitting_count -= bufsize;
-
-    return maybe_transmit(buf);
-}
-
-/******************************************************************************/
-/*!
-    @brief This function will write n elements into the array index specified by
-    the write pointer and increment the write index. If the write index
-    exceeds the max buffer size, then it will roll over to zero.
-
-    @param[in]  f
-                Pointer to the FIFO buffer to manipulate
-    @param[in]  p_data
-                The pointer to data to add to the FIFO
-    @param[in]  count
-                Number of element
-    @return Number of written elements
-*/
-/******************************************************************************/
-uint16_t tu_txbuf_write_n(tu_txbuf_t* txbuf, uint8_t const* buffer, uint32_t bufsize) {
-    uint32_t len;
-    int32_t last_free = txbuf->first_free - txbuf->pending_count - txbuf->transmitting_count - txbuf->padding;
-    if (last_free < 0) {
-        last_free += txbuf->buf_len;
-        len = last_free - txbuf->first_free;
-    } else {
-        len = txbuf->buf_len - txbuf->first_free;
-    }
-    if (bufsize < len) {
-        len = bufsize;
-    }
-    memcpy(txbuf->buffer + txbuf->first_free, buffer, len);
-    txbuf->first_free = (txbuf->first_free + len) % txbuf->buf_len;
-    txbuf->pending_count += len;
-    // Try to transmit now while we wrap the rest.
-    maybe_transmit(txbuf);
-    uint32_t remaining_bytes = bufsize - len;
-    if (remaining_bytes > 0 && last_free != txbuf->first_free) {
-        uint32_t second_len = remaining_bytes;
-        if (second_len > (uint32_t) last_free + 1) {
-            second_len = last_free + 1;
-        }
-        memcpy(txbuf->buffer, buffer + len, second_len);
-        txbuf->first_free = (txbuf->first_free + second_len) % txbuf->buf_len;
-        txbuf->pending_count += second_len;
-        len += second_len;
-    }
-
-    return len;
-}
-
-void tu_txbuf_set_ep_addr(tu_txbuf_t* txbuf, uint8_t ep_addr) {
-    txbuf->ep_addr = ep_addr;
-}
-
-/******************************************************************************/
-/*!
-    @brief Clear the txbuf including any currently transmitting data.
-
-    @param[in]  t
-                Pointer to the txbuf to manipulate
-*/
-/******************************************************************************/
-bool tu_txbuf_clear(tu_txbuf_t *txbuf)
-{
-
-  txbuf->first_free = 0;
-  txbuf->pending_count = 0;
-  txbuf->transmitting_count = 0;
-
-  return true;
-}

src/common/tusb_txbuf.h

@@ -1,83 +0,0 @@
-/**************************************************************************/
-/*!
-    @file     tusb_txbuf.h
-    @author   Scott Shawcroft
-
-    @section LICENSE
-
-    Software License Agreement (BSD License)
-
-    Copyright (c) 2018, Scott Shawcroft
-    All rights reserved.
-
-    Redistribution and use in source and binary forms, with or without
-    modification, are permitted provided that the following conditions are met:
-    1. Redistributions of source code must retain the above copyright
-    notice, this list of conditions and the following disclaimer.
-    2. Redistributions in binary form must reproduce the above copyright
-    notice, this list of conditions and the following disclaimer in the
-    documentation and/or other materials provided with the distribution.
-    3. Neither the name of the copyright holders nor the
-    names of its contributors may be used to endorse or promote products
-    derived from this software without specific prior written permission.
-
-    THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS ''AS IS'' AND ANY
-    EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
-    WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
-    DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER BE LIABLE FOR ANY
-    DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
-    INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
-    LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION HOWEVER CAUSED AND
-    ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
-    INCLUDING NEGLIGENCE OR OTHERWISE ARISING IN ANY WAY OUT OF THE USE OF THIS
-    SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
-
-	  This file is part of the tinyusb stack.
-*/
-/**************************************************************************/
-
-/** \ingroup Group_Common
- * \defgroup group_txbuf txbuf
- *  @{ */
-
-#ifndef _TUSB_TXBUF_H_
-#define _TUSB_TXBUF_H_
-
-#include <stdint.h>
-#include <stdbool.h>
-
-#ifdef __cplusplus
- extern "C" {
-#endif
-
-typedef bool (*edpt_xfer) (uint8_t rhport, uint8_t ep_addr, uint8_t* buffer, uint16_t total_bytes);
-
-
-/** \struct tu_txbuf_t
- * \brief Circular transmit buffer that manages USB transfer memory. It is not threadsafe and is
- *        only meant for use in the main task.
- */
-typedef struct
-{
-    uint8_t* buffer    ; ///< buffer pointer
-    uint16_t buf_len;
-    uint16_t first_free;
-    uint16_t pending_count;
-    uint16_t transmitting_count;
-    uint16_t padding;
-    uint8_t ep_addr;
-    edpt_xfer xfer;
-} tu_txbuf_t;
-
-bool tu_txbuf_clear(tu_txbuf_t *f);
-bool tu_txbuf_config(tu_txbuf_t *f, uint8_t* buffer, uint16_t depth, edpt_xfer xfer);
-
-uint16_t tu_txbuf_write_n (tu_txbuf_t* txbuf, uint8_t const * buffer, uint32_t length);
-void tu_txbuf_set_ep_addr(tu_txbuf_t* txbuf, uint8_t ep_addr);
-uint32_t tu_txbuf_transmit_done_cb(tu_txbuf_t* buf, uint32_t bufsize);
-
-#ifdef __cplusplus
- }
-#endif
-
-#endif /* _TUSB_TXBUF_H_ */

tests/common/Makefile

@@ -1,91 +0,0 @@
-ifeq ($(OS),Windows_NT)
-  ifeq ($(shell uname -s),) # not in a bash-like shell
-	CLEANUP = del /F /Q
-	MKDIR = mkdir
-  else # in a bash-like shell, like msys
-	CLEANUP = rm -f
-	MKDIR = mkdir -p
-  endif
-	TARGET_EXTENSION=.exe
-else
-	CLEANUP = rm -f
-	MKDIR = mkdir -p
-	TARGET_EXTENSION=out
-endif
-
-.PHONY: clean
-.PHONY: test
-
-PATHU = ../vendor/unity/src/
-PATHS = ../../src/
-PATHT = test/
-PATHB = build/
-PATHD = build/depends/
-PATHO = build/objs/
-PATHR = build/results/
-
-BUILD_PATHS = $(PATHB) $(PATHD) $(PATHO) $(PATHR)
-
-SRCT = $(wildcard $(PATHT)*.c)
-
-$(info $(SRCT))
-
-COMPILE=gcc -c
-LINK=gcc
-DEPEND=gcc -MM -MG -MF
-CFLAGS=-I. -I$(PATHU) -I$(PATHS) -DTEST
-
-RESULTS = $(patsubst $(PATHT)test%.c,$(PATHR)test%.txt,$(SRCT) )
-
-PASSED = `grep -s PASS $(PATHR)*.txt`
-FAIL = `grep -s FAIL $(PATHR)*.txt`
-IGNORE = `grep -s IGNORE $(PATHR)*.txt`
-
-test: $(BUILD_PATHS) $(RESULTS)
-	@echo "-----------------------\nIGNORES:\n-----------------------"
-	@echo "$(IGNORE)"
-	@echo "-----------------------\nFAILURES:\n-----------------------"
-	@echo "$(FAIL)"
-	@echo "-----------------------\nPASSED:\n-----------------------"
-	@echo "$(PASSED)"
-	@echo "\nDONE"
-
-$(PATHR)%.txt: $(PATHB)%.$(TARGET_EXTENSION)
-	-./$< > $@ 2>&1
-
-$(PATHB)test_%.$(TARGET_EXTENSION): $(PATHO)test_%.o $(PATHO)tusb_%.o $(PATHU)unity.o #$(PATHD)test%.d
-	$(LINK) -o $@ $^
-
-$(PATHO)%.o:: $(PATHT)%.c
-	$(COMPILE) $(CFLAGS) $< -o $@
-
-$(PATHO)%.o:: $(PATHS)common/%.c
-	$(COMPILE) $(CFLAGS) $< -o $@
-
-$(PATHO)%.o:: $(PATHU)%.c $(PATHU)%.h
-	$(COMPILE) $(CFLAGS) $< -o $@
-
-$(PATHD)%.d:: $(PATHT)%.c
-	$(DEPEND) $@ $<
-
-$(PATHB):
-	$(MKDIR) $(PATHB)
-
-$(PATHD):
-	$(MKDIR) $(PATHD)
-
-$(PATHO):
-	$(MKDIR) $(PATHO)
-
-$(PATHR):
-	$(MKDIR) $(PATHR)
-
-clean:
-	$(CLEANUP) $(PATHO)*.o
-	$(CLEANUP) $(PATHB)*.$(TARGET_EXTENSION)
-	$(CLEANUP) $(PATHR)*.txt
-
-.PRECIOUS: $(PATHB)test%.$(TARGET_EXTENSION)
-.PRECIOUS: $(PATHD)%.d
-.PRECIOUS: $(PATHO)%.o
-.PRECIOUS: $(PATHR)%.txt

tests/common/build/results/test_txbuf.txt

@@ -1,8 +0,0 @@
-test/test_txbuf.c:140:test_normal:PASS
-test/test_txbuf.c:141:test_nearly_full:PASS
-test/test_txbuf.c:142:test_wrap_around:PASS
-test/test_txbuf.c:143:test_wrap_around_too_much:PASS
-
------------------------
-4 Tests 0 Failures 0 Ignored 
-OK

tests/common/test/test_txbuf.c

@@ -1,145 +0,0 @@
-/**************************************************************************/
-/*!
-    @file     test_fifo.c
-    @author   Scott Shawcroft
-
-    @section LICENSE
-
-    Software License Agreement (BSD License)
-
-    Copyright (c) 2019, Scott Shawcroft
-    All rights reserved.
-
-    Redistribution and use in source and binary forms, with or without
-    modification, are permitted provided that the following conditions are met:
-    1. Redistributions of source code must retain the above copyright
-    notice, this list of conditions and the following disclaimer.
-    2. Redistributions in binary form must reproduce the above copyright
-    notice, this list of conditions and the following disclaimer in the
-    documentation and/or other materials provided with the distribution.
-    3. Neither the name of the copyright holders nor the
-    names of its contributors may be used to endorse or promote products
-    derived from this software without specific prior written permission.
-
-    THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS ''AS IS'' AND ANY
-    EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
-    WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
-    DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER BE LIABLE FOR ANY
-    DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
-    INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
-    LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION HOWEVER CAUSED AND
-    ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
-    INCLUDING NEGLIGENCE OR OTHERWISE ARISING IN ANY WAY OUT OF THE USE OF THIS
-    SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
-
-    This file is part of the tinyusb stack.
-*/
-/**************************************************************************/
-
-#include "unity.h"
-#include "common/tusb_txbuf.h"
-
-uint32_t xfer_count = 0;
-uint32_t freshly_transmitted = 0;
-
-bool mock_xfer(uint8_t rhport, uint8_t ep_addr, uint8_t* buffer, uint16_t total_bytes) {
-    TEST_ASSERT_EQUAL_INT_MESSAGE(0, ((size_t) buffer) % 4, "Transferred buffer not word aligned.");
-    xfer_count++;
-    freshly_transmitted += total_bytes;
-    return true;
-}
-
-tu_txbuf_t txbuf;
-__attribute__((aligned(4))) uint8_t buffer[16];
-
-uint8_t data[] = {1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16};
-
-void setUp(void) {
-    tu_txbuf_config(&txbuf, buffer, 16, mock_xfer);
-    tu_txbuf_set_ep_addr(&txbuf, 1);
-}
-
-void tearDown(void) {
-    xfer_count = 0;
-    freshly_transmitted = 0;
-}
-
-void xfer_callback(void) {
-    uint32_t previously_transmitted = freshly_transmitted;
-    freshly_transmitted = 0;
-
-    tu_txbuf_transmit_done_cb(&txbuf, previously_transmitted);
-}
-
-// Test that we transfer immediately at the start and that the pointer is rounded to a word.
-void test_normal(void) {
-    uint16_t written = tu_txbuf_write_n(&txbuf, data, 4);
-    TEST_ASSERT_EQUAL_INT(4, written);
-    TEST_ASSERT_EQUAL_INT(1, xfer_count);
-    xfer_callback();
-    TEST_ASSERT_EQUAL_INT(1, xfer_count);
-}
-
-// Test that we only accept the data we have room for.
-void test_nearly_full(void) {
-    uint16_t written = tu_txbuf_write_n(&txbuf, data, 11);
-    TEST_ASSERT_EQUAL_INT(11, written);
-    TEST_ASSERT_EQUAL_INT(1, xfer_count);
-
-    written = tu_txbuf_write_n(&txbuf, data, 11);
-    // We only have space for 4 more bytes because 11 + padding are being written.
-    TEST_ASSERT_EQUAL_INT(4, written);
-
-    // Callback triggers a second write of remaining data.
-    xfer_callback();
-    TEST_ASSERT_EQUAL_INT(2, xfer_count);
-    TEST_ASSERT_EQUAL_INT(4, freshly_transmitted);
-}
-
-// Test that we only accept the data even when we have to wrap around.
-void test_wrap_around(void) {
-    uint16_t written = tu_txbuf_write_n(&txbuf, data, 11);
-    TEST_ASSERT_EQUAL_INT(11, written);
-    TEST_ASSERT_EQUAL_INT(1, xfer_count);
-    xfer_callback();
-    TEST_ASSERT_EQUAL_INT(1, xfer_count);
-
-    written = tu_txbuf_write_n(&txbuf, data, 11);
-    // We can queue all 11 bytes but they are split.
-    TEST_ASSERT_EQUAL_INT(11, written);
-    // Four immediately and seven more after the callback.
-    TEST_ASSERT_EQUAL_INT(2, xfer_count);
-    TEST_ASSERT_EQUAL_INT(4, freshly_transmitted);
-    xfer_callback();
-    TEST_ASSERT_EQUAL_INT(7, freshly_transmitted);
-    TEST_ASSERT_EQUAL_INT(3, xfer_count);
-}
-
-// Test that we only accept the data even when we have to wrap around.
-void test_wrap_around_too_much(void) {
-    uint16_t written = tu_txbuf_write_n(&txbuf, data, 11);
-    TEST_ASSERT_EQUAL_INT(11, written);
-    TEST_ASSERT_EQUAL_INT(1, xfer_count);
-    xfer_callback();
-    TEST_ASSERT_EQUAL_INT(1, xfer_count);
-
-    written = tu_txbuf_write_n(&txbuf, data, 17);
-    // We can queue 16 of 17 bytes but they are split.
-    TEST_ASSERT_EQUAL_INT(16, written);
-    // Four immediately and 12 more after the callback.
-    TEST_ASSERT_EQUAL_INT(2, xfer_count);
-    TEST_ASSERT_EQUAL_INT(4, freshly_transmitted);
-    xfer_callback();
-    TEST_ASSERT_EQUAL_INT(12, freshly_transmitted);
-    TEST_ASSERT_EQUAL_INT(3, xfer_count);
-}
-
-int main(void)
-{
-UNITY_BEGIN();
-RUN_TEST(test_normal);
-RUN_TEST(test_nearly_full);
-RUN_TEST(test_wrap_around);
-RUN_TEST(test_wrap_around_too_much);
-return UNITY_END();
-}