samd/mphalport: Fix USB CDC tx handling to work reliably.
@@ -80,17 +80,16 @@ void mp_hal_stdout_tx_strn(const char *str, mp_uint_t len) {
if (tud_cdc_connected()) {
for (size_t i = 0; i < len;) {
uint32_t n = len - i;
- uint32_t n2 = tud_cdc_write(str + i, n);
- if (n2 < n) {
- while (!tud_cdc_write_flush()) {
- __WFI();
+ if (n > CFG_TUD_CDC_EP_BUFSIZE) {
+ n = CFG_TUD_CDC_EP_BUFSIZE;
}
+ while (n > tud_cdc_write_available()) {
+ __WFI();
}
+ uint32_t n2 = tud_cdc_write(str + i, n);
+ tud_cdc_write_flush();
i += n2;
}
- while (!tud_cdc_write_flush()) {
- __WFI();
- }
}
while (len--) {
while (!(USARTx->USART.INTFLAG.bit.DRE)) {
