1 files changed, 8 insertions, 5 deletions

diff --git a/sys/dev/usb/ucom.c b/sys/dev/usb/ucom.c
index f85619563cb2..44dd458ad236 100644
--- a/sys/dev/usb/ucom.c
+++ b/sys/dev/usb/ucom.c
@@ -381,6 +381,7 @@ ucomopen(struct cdev *dev, int flag, int mode, usb_proc_ptr p)
 		    (minor(dev) & UCOM_CALLOUT_MASK))
 			ttyld_modem(tp, 1);
 
+		sc->sc_state |= UCS_RXSTOP;
 		ucomstartread(sc);
 	}
 
@@ -929,7 +930,7 @@ 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);
@@ -1009,10 +1010,9 @@ 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,
@@ -1021,7 +1021,8 @@ 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);
 	}
@@ -1046,11 +1047,13 @@ 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));