diff --git a/drivers/usb/dwc3/gadget.c b/drivers/usb/dwc3/gadget.c index 4db97ecae885..f875b3f4b0ec 100644 --- a/drivers/usb/dwc3/gadget.c +++ b/drivers/usb/dwc3/gadget.c @@ -1342,6 +1342,68 @@ static int dwc3_gadget_ep_dequeue(struct usb_ep *ep, if (r == req) { /* wait until it is processed */ dwc3_stop_active_transfer(dwc, dep->number, true); + + /* + * If request was already started, this means we had to + * stop the transfer. With that we also need to ignore + * all TRBs used by the request, however TRBs can only + * be modified after completion of END_TRANSFER + * command. So what we do here is that we wait for + * END_TRANSFER completion and only after that, we jump + * over TRBs by clearing HWO and incrementing dequeue + * pointer. + * + * Note that we have 2 possible types of transfers here: + * + * i) Linear buffer request + * ii) SG-list based request + * + * SG-list based requests will have r->num_pending_sgs + * set to a valid number (> 0). Linear requests, + * normally use a single TRB. + * + * For each of these two cases, if r->unaligned flag is + * set, one extra TRB has been used to align transfer + * size to wMaxPacketSize. + * + * All of these cases need to be taken into + * consideration so we don't mess up our TRB ring + * pointers. + */ + wait_event_lock_irq(dep->wait_end_transfer, + !(dep->flags & DWC3_EP_END_TRANSFER_PENDING), + dwc->lock); + + if (!r->trb) + goto out1; + + if (r->num_pending_sgs) { + struct dwc3_trb *trb; + int i = 0; + + for (i = 0; i < r->num_pending_sgs; i++) { + trb = r->trb + i; + trb->ctrl &= ~DWC3_TRB_CTRL_HWO; + dwc3_ep_inc_deq(dep); + } + + if (r->unaligned) { + trb = r->trb + r->num_pending_sgs + 1; + trb->ctrl &= ~DWC3_TRB_CTRL_HWO; + dwc3_ep_inc_deq(dep); + } + } else { + struct dwc3_trb *trb = r->trb; + + trb->ctrl &= ~DWC3_TRB_CTRL_HWO; + dwc3_ep_inc_deq(dep); + + if (r->unaligned) { + trb = r->trb + 1; + trb->ctrl &= ~DWC3_TRB_CTRL_HWO; + dwc3_ep_inc_deq(dep); + } + } goto out1; } dev_err(dwc->dev, "request %p was not queued to %s\n", @@ -1352,6 +1414,7 @@ static int dwc3_gadget_ep_dequeue(struct usb_ep *ep, out1: /* giveback the request */ + dep->queued_requests--; dwc3_gadget_giveback(dep, req, -ECONNRESET); out0: