On Fri, Jan 25, 2019 at 05:51:53PM -0800, Jack Pham wrote:

commit bd6742249b9ca918565e4e3abaa06665e587f4b5 upstream.

OUT endpoint requests may somtimes have one of these flags 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 unaligned or zero 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 flags are 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") Signed-off-by: Jack Pham jackp@codeaurora.org Signed-off-by: Felipe Balbi felipe.balbi@linux.intel.com [jackp: backport to <= 4.20: replaced 'needs_extra_trb' with 'unaligned' and 'zero' members in patch and reworded commit text] Signed-off-by: Jack Pham jackp@codeaurora.org

---

drivers/usb/dwc3/gadget.c | 2 ++ 1 file changed, 2 insertions(+)

diff --git a/drivers/usb/dwc3/gadget.c b/drivers/usb/dwc3/gadget.c index 9f92ee03dde7..2a4ea9a1b1e3 100644 --- a/drivers/usb/dwc3/gadget.c +++ b/drivers/usb/dwc3/gadget.c @@ -177,6 +177,8 @@ static void dwc3_gadget_del_and_unmap_request(struct dwc3_ep *dep, req->started = false; list_del(&req->list); req->remaining = 0;

• req->unaligned = false;

• req->zero = false;

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

Thanks! I'll let Greg pick it up (as the upstream patch was explicitly tagged for stable).

-- Thanks, Sasha