Merge pull request #2630 from HiFiPhile/dcd_race

1 files changed, 8 insertions, 0 deletions

diff --git a/src/class/cdc/cdc_device.c b/src/class/cdc/cdc_device.c
index 681a1b852..ebc408f5a 100644
--- a/src/class/cdc/cdc_device.c
+++ b/src/class/cdc/cdc_device.c
@@ -83,6 +83,10 @@ static tud_cdc_configure_fifo_t _cdcd_fifo_cfg;
 
 static bool _prep_out_transaction (cdcd_interface_t* p_cdc) {
   uint8_t const rhport = 0;
+
+  // Skip if usb is not ready yet
+  TU_VERIFY(tud_ready() && p_cdc->ep_out);
+
   uint16_t available = tu_fifo_remaining(&p_cdc->rx_ff);
 
   // Prepare for incoming data but only allow what we can store in the ring buffer.
@@ -116,6 +120,10 @@ bool tud_cdc_configure_fifo(tud_cdc_configure_fifo_t const* cfg) {
   return true;
 }
 
+bool tud_cdc_n_ready(uint8_t itf) {
+  return tud_ready() && _cdcd_itf[itf].ep_in != 0 && _cdcd_itf[itf].ep_out != 0;
+}
+
 bool tud_cdc_n_connected(uint8_t itf) {
   // DTR (bit 0) active  is considered as connected
   return tud_ready() && tu_bit_test(_cdcd_itf[itf].line_state, 0);