Commit b5d521a3 authored May 21, 2020 by Thinh Nguyen Committed by Mayank Rana May 21, 2020

usb: dwc3: gadget: Give back staled requests



If a request is dequeued, the transfer is cancelled. Give back all
the started requests.

In most scenarios, the function driver dequeues all requests of a
transfer when there's a failure. If the function driver follows this,
then it's fine. If not, then we'd be skipping TRBs at different points
within the dequeue and enqueue pointers, making dequeue/enqueue pointers
useless. To enforce and make sure that we're properly skipping TRBs,
cancel all the started requests and give back all the cancelled requests
to the function drivers.

Change-Id: Ia344a480048383f3fd7c16afbc9f7b0062492879
Signed-off-by: Thinh Nguyen <thinhn@synopsys.com>
Patch-mainline: linux-usb @ 05/03/20, 13:24
Signed-off-by: Mayank Rana <mrana@codeaurora.org>

parent f5e30025

drivers/usb/dwc3/gadget.c

+14 −1

Original line number	Diff line number	Diff line
		@@ -1682,6 +1682,11 @@ static int dwc3_gadget_ep_dequeue(struct usb_ep *ep,

		spin_lock_irqsave(&dwc->lock, flags);

		list_for_each_entry(r, &dep->cancelled_list, list) {
		if (r == req)
		goto out0;
		}

		list_for_each_entry(r, &dep->pending_list, list) {
		if (r == req)
		break;
		@@ -1693,13 +1698,21 @@ static int dwc3_gadget_ep_dequeue(struct usb_ep *ep,
		break;
		}
		if (r == req) {
		struct dwc3_request *t;

		/* wait until it is processed */
		dwc3_stop_active_transfer(dep, true, true);

		if (!r->trb)
		goto out0;

		dwc3_gadget_move_cancelled_request(req);
		/*
		* Remove any started request if the transfer is
		* cancelled.
		*/
		list_for_each_entry_safe(r, t, &dep->started_list, list)
		dwc3_gadget_move_cancelled_request(r);

		if (dep->flags & DWC3_EP_TRANSFER_STARTED)
		goto out0;
		else