1 files changed, 84 insertions, 13 deletions

diff --git a/drivers/usb/dwc3/gadget.c b/drivers/usb/dwc3/gadget.c
index 4db97ecae885..79e7a3480d51 100644
--- a/drivers/usb/dwc3/gadget.c
+++ b/drivers/usb/dwc3/gadget.c
@@ -171,6 +171,7 @@ void dwc3_gadget_giveback(struct dwc3_ep *dep, struct dwc3_request *req,
                 int status)
 {
         struct dwc3                     *dwc = dep->dwc;
+        unsigned int                    unmap_after_complete = false;
 
         req->started = false;
         list_del(&req->list);
@@ -180,11 +181,19 @@ void dwc3_gadget_giveback(struct dwc3_ep *dep, struct dwc3_request *req,
         if (req->request.status == -EINPROGRESS)
                 req->request.status = status;
 
-        if (dwc->ep0_bounced && dep->number <= 1)
+        /*
+         * NOTICE we don't want to unmap before calling ->complete() if we're
+         * dealing with a bounced ep0 request. If we unmap it here, we would end
+         * up overwritting the contents of req->buf and this could confuse the
+         * gadget driver.
+         */
+        if (dwc->ep0_bounced && dep->number <= 1) {
                 dwc->ep0_bounced = false;
-
-        usb_gadget_unmap_request_by_dev(dwc->sysdev,
-                        &req->request, req->direction);
+                unmap_after_complete = true;
+        } else {
+                usb_gadget_unmap_request_by_dev(dwc->sysdev,
+                                &req->request, req->direction);
+        }
 
         trace_dwc3_gadget_giveback(req);
 
@@ -192,6 +201,10 @@ void dwc3_gadget_giveback(struct dwc3_ep *dep, struct dwc3_request *req,
         usb_gadget_giveback_request(&dep->endpoint, &req->request);
         spin_lock(&dwc->lock);
 
+        if (unmap_after_complete)
+                usb_gadget_unmap_request_by_dev(dwc->sysdev,
+                                &req->request, req->direction);
+
         if (dep->number > 1)
                 pm_runtime_put(dwc->dev);
 }
@@ -1342,6 +1355,68 @@ 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 +1427,7 @@ static int dwc3_gadget_ep_dequeue(struct usb_ep *ep,
 
 out1:
         /* giveback the request */
+        dep->queued_requests--;
         dwc3_gadget_giveback(dep, req, -ECONNRESET);
 
 out0:
@@ -2126,12 +2202,12 @@ static int __dwc3_cleanup_done_trbs(struct dwc3 *dwc, struct dwc3_ep *dep,
                 return 1;
         }
 
-        if ((trb->ctrl & DWC3_TRB_CTRL_HWO) && status != -ESHUTDOWN)
-                return 1;
-
         count = trb->size & DWC3_TRB_SIZE_MASK;
         req->remaining += count;
 
+        if ((trb->ctrl & DWC3_TRB_CTRL_HWO) && status != -ESHUTDOWN)
+                return 1;
+
         if (dep->direction) {
                 if (count) {
                         trb_status = DWC3_TRB_SIZE_TRBSTS(trb->size);
@@ -3228,15 +3304,10 @@ void dwc3_gadget_exit(struct dwc3 *dwc)
 
 int dwc3_gadget_suspend(struct dwc3 *dwc)
 {
-        int ret;
-
         if (!dwc->gadget_driver)
                 return 0;
 
-        ret = dwc3_gadget_run_stop(dwc, false, false);
-        if (ret < 0)
-                return ret;
-
+        dwc3_gadget_run_stop(dwc, false, false);
         dwc3_disconnect_gadget(dwc);
         __dwc3_gadget_stop(dwc);