From 0672cb8460dab60a3b668217b0c96bb3626ae191 Mon Sep 17 00:00:00 2001
From: Misaka19465 <19465@misakanet.team>
Date: Sun, 15 Sep 2024 15:49:58 +0800
Subject: [PATCH 1/2] add Adafruit_USBD_CDC::ignoreFlowControl
MIME-Version: 1.0
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In some cases, the target application will not assert the DTR virtual line, thus preventing writing operations to succeed.
For this reason, the Adafruit_USBD_CDC::ignoreFlowControl() method disables the connection’s state verification, enabling the program to write on the port, even though the data might be lost.
---
 src/arduino/Adafruit_USBD_CDC.cpp |  6 +++++-
 src/arduino/Adafruit_USBD_CDC.h   | 10 ++++++++++
 2 files changed, 15 insertions(+), 1 deletion(-)

diff --git a/src/arduino/Adafruit_USBD_CDC.cpp b/src/arduino/Adafruit_USBD_CDC.cpp
index 893db83e..6345043a 100644
--- a/src/arduino/Adafruit_USBD_CDC.cpp
+++ b/src/arduino/Adafruit_USBD_CDC.cpp
@@ -118,6 +118,10 @@ void Adafruit_USBD_CDC::end(void) {
   _instance = INVALID_INSTANCE;
 }
 
+void Adafruit_USBD_CDC::ignoreFlowControl(bool ignore) {
+  _ignoreFlowControl = ignore;
+}
+
 uint32_t Adafruit_USBD_CDC::baud(void) {
   if (!isValid()) {
     return 0;
@@ -243,7 +247,7 @@ size_t Adafruit_USBD_CDC::write(const uint8_t *buffer, size_t size) {
   }
 
   size_t remain = size;
-  while (remain && tud_cdc_n_connected(_instance)) {
+  while (remain && (tud_cdc_n_connected(_instance) || _ignoreFlowControl)) {
     size_t wrcount = tud_cdc_n_write(_instance, buffer, remain);
     remain -= wrcount;
     buffer += wrcount;
diff --git a/src/arduino/Adafruit_USBD_CDC.h b/src/arduino/Adafruit_USBD_CDC.h
index 9c0952f3..8d0dab16 100644
--- a/src/arduino/Adafruit_USBD_CDC.h
+++ b/src/arduino/Adafruit_USBD_CDC.h
@@ -54,6 +54,14 @@ class Adafruit_USBD_CDC : public Stream, public Adafruit_USBD_Interface {
   void begin(uint32_t baud, uint8_t config);
   void end(void);
 
+  // In some cases, the target application will not assert
+  // the DTR virtual line, thus preventing writing operations
+  // to succeed. For this reason, the
+  // Adafruit_USBD_CDC::ignoreFlowControl() method disables the
+  // connection’s state verification, enabling the program to
+  // write on the port, even though the data might be lost.
+  void ignoreFlowControl(bool ignore = true);
+
   // return line coding set by host
   uint32_t baud(void);
   uint8_t stopbits(void);
@@ -90,6 +98,8 @@ class Adafruit_USBD_CDC : public Stream, public Adafruit_USBD_Interface {
 
   uint8_t _instance;
 
+  bool _ignoreFlowControl = false;
+
   bool isValid(void) { return _instance != INVALID_INSTANCE; }
 };
 

From e674b684745504f489d76e4af034e2b35db3b206 Mon Sep 17 00:00:00 2001
From: Misaka19465 <19465@misakanet.team>
Date: Wed, 18 Sep 2024 22:56:25 +0800
Subject: [PATCH 2/2] Limit Adafruit_USBD_CDC::ignoreFlowcontrol to rp2040 core

Adafruit_USBD_CDC::ignoreFlowcontrol added in
0672cb8 may only work for rp2040 for
now.
So add #ifdef to limit this method to rp2040 core only.
---
 src/arduino/Adafruit_USBD_CDC.cpp | 9 ++++++++-
 src/arduino/Adafruit_USBD_CDC.h   | 4 ++++
 2 files changed, 12 insertions(+), 1 deletion(-)

diff --git a/src/arduino/Adafruit_USBD_CDC.cpp b/src/arduino/Adafruit_USBD_CDC.cpp
index 6345043a..8be4bfe5 100644
--- a/src/arduino/Adafruit_USBD_CDC.cpp
+++ b/src/arduino/Adafruit_USBD_CDC.cpp
@@ -118,9 +118,11 @@ void Adafruit_USBD_CDC::end(void) {
   _instance = INVALID_INSTANCE;
 }
 
+#ifdef ARDUINO_ARCH_RP2040
 void Adafruit_USBD_CDC::ignoreFlowControl(bool ignore) {
   _ignoreFlowControl = ignore;
 }
+#endif
 
 uint32_t Adafruit_USBD_CDC::baud(void) {
   if (!isValid()) {
@@ -247,7 +249,12 @@ size_t Adafruit_USBD_CDC::write(const uint8_t *buffer, size_t size) {
   }
 
   size_t remain = size;
-  while (remain && (tud_cdc_n_connected(_instance) || _ignoreFlowControl)) {
+#ifdef ARDUINO_ARCH_RP2040
+  while (remain && (tud_cdc_n_connected(_instance) || _ignoreFlowControl))
+#else
+  while (remain && tud_cdc_n_connected(_instance))
+#endif
+  {
     size_t wrcount = tud_cdc_n_write(_instance, buffer, remain);
     remain -= wrcount;
     buffer += wrcount;
diff --git a/src/arduino/Adafruit_USBD_CDC.h b/src/arduino/Adafruit_USBD_CDC.h
index 8d0dab16..793d482e 100644
--- a/src/arduino/Adafruit_USBD_CDC.h
+++ b/src/arduino/Adafruit_USBD_CDC.h
@@ -54,6 +54,7 @@ class Adafruit_USBD_CDC : public Stream, public Adafruit_USBD_Interface {
   void begin(uint32_t baud, uint8_t config);
   void end(void);
 
+#ifdef ARDUINO_ARCH_RP2040
   // In some cases, the target application will not assert
   // the DTR virtual line, thus preventing writing operations
   // to succeed. For this reason, the
@@ -61,6 +62,7 @@ class Adafruit_USBD_CDC : public Stream, public Adafruit_USBD_Interface {
   // connection’s state verification, enabling the program to
   // write on the port, even though the data might be lost.
   void ignoreFlowControl(bool ignore = true);
+#endif
 
   // return line coding set by host
   uint32_t baud(void);
@@ -98,7 +100,9 @@ class Adafruit_USBD_CDC : public Stream, public Adafruit_USBD_Interface {
 
   uint8_t _instance;
 
+#ifdef ARDUINO_ARCH_RP2040
   bool _ignoreFlowControl = false;
+#endif
 
   bool isValid(void) { return _instance != INVALID_INSTANCE; }
 };