The patch below does not apply to the 4.20-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to stable@vger.kernel.org.

thanks,

greg k-h

------------------ original commit in Linus's tree ------------------

From bd6742249b9ca918565e4e3abaa06665e587f4b5 Mon Sep 17 00:00:00 2001

From: Jack Pham jackp@codeaurora.org Date: Thu, 10 Jan 2019 12:39:55 -0800 Subject: [PATCH] usb: dwc3: gadget: Clear req->needs_extra_trb flag on cleanup

OUT endpoint requests may somtimes have this flag set when preparing to be submitted to HW indicating that there is an additional TRB chained to the request for alignment purposes. If that request is removed before the controller can execute the transfer (e.g. ep_dequeue/ep_disable), the request will not go through the dwc3_gadget_ep_cleanup_completed_request() handler and will not have its needs_extra_trb flag cleared when dwc3_gadget_giveback() is called. This same request could be later requeued for a new transfer that does not require an extra TRB and if it is successfully completed, the cleanup and TRB reclamation will incorrectly process the additional TRB which belongs to the next request, and incorrectly advances the TRB dequeue pointer, thereby messing up calculation of the next requeust's actual/remaining count when it completes.

The right thing to do here is to ensure that the flag is cleared before it is given back to the function driver. A good place to do that is in dwc3_gadget_del_and_unmap_request().

Fixes: c6267a51639b ("usb: dwc3: gadget: align transfers to wMaxPacketSize") Cc: stable@vger.kernel.org Signed-off-by: Jack Pham jackp@codeaurora.org Signed-off-by: Felipe Balbi felipe.balbi@linux.intel.com

diff --git a/drivers/usb/dwc3/gadget.c b/drivers/usb/dwc3/gadget.c index 851fd44d56ad..6e2b6d6369aa 100644 --- a/drivers/usb/dwc3/gadget.c +++ b/drivers/usb/dwc3/gadget.c @@ -177,6 +177,7 @@ static void dwc3_gadget_del_and_unmap_request(struct dwc3_ep *dep, req->started = false; list_del(&req->list); req->remaining = 0; + req->needs_extra_trb = false;

if (req->request.status == -EINPROGRESS) req->request.status = status;