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Workaround for when USB CDC is unplugged #7583

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Merged
merged 4 commits into from
Dec 14, 2022
Merged

Workaround for when USB CDC is unplugged #7583

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f3ed691
Workaround for when USB CDC is unplugged
SuGlider Dec 12, 2022
88f7a5e
Considers default TX timeout
SuGlider Dec 13, 2022
f8ed7eb
fixed left over code
SuGlider Dec 13, 2022
4a2da36
Merge branch 'master' into USB-CDC-Unplugged
SuGlider Dec 13, 2022
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16 changes: 14 additions & 2 deletions cores/esp32/HWCDC.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -32,7 +32,11 @@ static uint8_t rx_data_buf[64];
static intr_handle_t intr_handle = NULL;
static volatile bool initial_empty = false;
static xSemaphoreHandle tx_lock = NULL;
static uint32_t tx_timeout_ms = 200;

// workaround for when USB CDC is not connected
static uint32_t tx_timeout_ms = 0;
static bool tx_timeout_change_request = false;

static esp_event_loop_handle_t arduino_hw_cdc_event_loop_handle = NULL;

static esp_err_t arduino_hw_cdc_event_post(esp_event_base_t event_base, int32_t event_id, void *event_data, size_t event_data_size, BaseType_t *task_unblocked){
Expand Down Expand Up @@ -72,9 +76,14 @@ static void hw_cdc_isr_handler(void *arg) {
if (usb_serial_jtag_ll_txfifo_writable() == 1) {
// We disable the interrupt here so that the interrupt won't be triggered if there is no data to send.
usb_serial_jtag_ll_disable_intr_mask(USB_SERIAL_JTAG_INTR_SERIAL_IN_EMPTY);

if(!initial_empty){
initial_empty = true;
// First time USB is plugged and the application has not explicitly set TX Timeout, set it to default 100ms.
// Otherwise, USB is still unplugged and the timeout will be kept as Zero in order to avoid any delay in the
// application whenever it uses write() and the TX Queue gets full.
if (!tx_timeout_change_request) {
tx_timeout_ms = 100;
}
//send event?
//ets_printf("CONNECTED\n");
arduino_hw_cdc_event_post(ARDUINO_HW_CDC_EVENTS, ARDUINO_HW_CDC_CONNECTED_EVENT, &event, sizeof(arduino_hw_cdc_event_data_t), &xTaskWoken);
Expand Down Expand Up @@ -197,6 +206,9 @@ void HWCDC::end()

void HWCDC::setTxTimeoutMs(uint32_t timeout){
tx_timeout_ms = timeout;
// it registers that the user has explicitly requested to use a value as TX timeout
// used for the workaround with unplugged USB and TX Queue Full that causes a delay on every write()
tx_timeout_change_request = true;
}

/*
Expand Down