1 files changed, 18 insertions, 4 deletions

diff --git a/sys/dev/usb/usb_transfer.c b/sys/dev/usb/usb_transfer.c
index e7cb202aef57..9be1c0f4bde0 100644
--- a/sys/dev/usb/usb_transfer.c
+++ b/sys/dev/usb/usb_transfer.c
@@ -2410,21 +2410,24 @@ usbd_pipe_start(struct usb_xfer_queue *pq)
 	 * Check if we are supposed to stall the endpoint:
 	 */
 	if (xfer->flags.stall_pipe) {
+		struct usb_device *udev;
+		struct usb_xfer_root *info;
+
 		/* clear stall command */
 		xfer->flags.stall_pipe = 0;
 
+		/* get pointer to USB device */
+		info = xfer->xroot;
+		udev = info->udev;
+
 		/*
 		 * Only stall BULK and INTERRUPT endpoints.
 		 */
 		type = (ep->edesc->bmAttributes & UE_XFERTYPE);
 		if ((type == UE_BULK) ||
 		    (type == UE_INTERRUPT)) {
-			struct usb_device *udev;
-			struct usb_xfer_root *info;
 			uint8_t did_stall;
 
-			info = xfer->xroot;
-			udev = info->udev;
 			did_stall = 1;
 
 			if (udev->flags.usb_mode == USB_MODE_DEVICE) {
@@ -2452,6 +2455,17 @@ usbd_pipe_start(struct usb_xfer_queue *pq)
 				ep->is_stalled = 1;
 				return;
 			}
+		} else if (type == UE_ISOCHRONOUS) {
+
+			/* 
+			 * Make sure any FIFO overflow or other FIFO
+			 * error conditions go away by resetting the
+			 * endpoint FIFO through the clear stall
+			 * method.
+			 */
+			if (udev->flags.usb_mode == USB_MODE_DEVICE) {
+				(udev->bus->methods->clear_stall) (udev, ep);
+			}
 		}
 	}
 	/* Set or clear stall complete - special case */