1 files changed, 8 insertions, 5 deletions

diff --git a/sys/dev/usb/ucom.c b/sys/dev/usb/ucom.c
index 445609c81c26..0260cb6d8c9f 100644
--- a/sys/dev/usb/ucom.c
+++ b/sys/dev/usb/ucom.c
@@ -297,6 +297,7 @@ ucomopen(struct tty *tp, struct cdev *dev)
 		goto fail;
 	}
 
+	sc->sc_state |= UCS_RXSTOP;
 	ucomstartread(sc);
 
 	sc->sc_poll = 1;
@@ -621,7 +622,7 @@ ucomstop(struct tty *tp, int flag)
 
 	DPRINTF(("ucomstop: %d\n", flag));
 
-	if (flag & FREAD) {
+	if ((flag & FREAD) && (sc->sc_state & UCS_RXSTOP) == 0) {
 		DPRINTF(("ucomstop: read\n"));
 		ucomstopread(sc);
 		ucomstartread(sc);
@@ -701,10 +702,9 @@ ucomstartread(struct ucom_softc *sc)
 
 	DPRINTF(("ucomstartread: start\n"));
 
-	sc->sc_state &= ~UCS_RXSTOP;
-
-	if (sc->sc_bulkin_pipe == NULL)
+	if (sc->sc_bulkin_pipe == NULL || (sc->sc_state & UCS_RXSTOP) == 0)
 		return (USBD_NORMAL_COMPLETION);
+	sc->sc_state &= ~UCS_RXSTOP;
 
 	usbd_setup_xfer(sc->sc_ixfer, sc->sc_bulkin_pipe,
 			(usbd_private_handle)sc,
@@ -713,7 +713,8 @@ ucomstartread(struct ucom_softc *sc)
 			USBD_NO_TIMEOUT, ucomreadcb);
 
 	err = usbd_transfer(sc->sc_ixfer);
-	if (err != USBD_IN_PROGRESS) {
+	if (err && err != USBD_IN_PROGRESS) {
+		sc->sc_state |= UCS_RXSTOP;
 		DPRINTF(("ucomstartread: err = %s\n", usbd_errstr(err)));
 		return (err);
 	}
@@ -738,11 +739,13 @@ ucomreadcb(usbd_xfer_handle xfer, usbd_private_handle p, usbd_status status)
 		if (!(sc->sc_state & UCS_RXSTOP))
 			printf("%s: ucomreadcb: %s\n",
 			       USBDEVNAME(sc->sc_dev), usbd_errstr(status));
+		sc->sc_state |= UCS_RXSTOP;
 		if (status == USBD_STALLED)
 			usbd_clear_endpoint_stall_async(sc->sc_bulkin_pipe);
 		/* XXX we should restart after some delay. */
 		return;
 	}
+	sc->sc_state |= UCS_RXSTOP;
 
 	usbd_get_xfer_status(xfer, NULL, (void **)&cp, &cc, NULL);
 	DPRINTF(("ucomreadcb: got %d chars, tp = %p\n", cc, tp));