1 files changed, 2 insertions, 0 deletions
diff --git a/os/hal/src/serial_usb.c b/os/hal/src/serial_usb.c
index 29aec2650..430218edb 100644
--- a/os/hal/src/serial_usb.c
+++ b/os/hal/src/serial_usb.c
@@ -124,6 +124,7 @@ static void inotify(GenericQueue *qp) {
     if (n != USB_ENDPOINT_BUSY) {
       sdup->iqueue.q_rdptr = sdup->iqueue.q_buffer;
       chSemSetCounterI(&sdup->iqueue.q_sem, n);
+      chIOAddFlagsI(sdup, IO_INPUT_AVAILABLE);
     }
   }
 }
@@ -142,6 +143,7 @@ static void onotify(GenericQueue *qp) {
   if (n != USB_ENDPOINT_BUSY) {
     sdup->oqueue.q_wrptr = sdup->oqueue.q_buffer;
     chSemSetCounterI(&sdup->oqueue.q_sem, SERIAL_USB_BUFFERS_SIZE);
+    chIOAddFlagsI(sdup, IO_OUTPUT_EMPTY);
   }
 }