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Commit 08a36b54 authored by Felipe Balbi's avatar Felipe Balbi
Browse files

usb: dwc3: gadget: simplify __dwc3_gadget_ep_queue() 



Many of the comments in that function are really
outdated and don't match what the driver is
doing. Moreover, recent patches combined programming
model for all non-control endpoints, this gives us
an opportunity to get rid of our special cases in
__dwc3_gadget_ep_queue().

Signed-off-by: default avatarFelipe Balbi <felipe.balbi@linux.intel.com>
parent 45438a0c

drivers/usb/dwc3/gadget.c

+7 −76
Original line number Diff line number Diff line
@@ -1063,18 +1063,6 @@ static int __dwc3_gadget_ep_queue(struct dwc3_ep *dep, struct dwc3_request *req) 


	trace_dwc3_ep_queue(req);



	/*

	 * We only add to our list of requests now and

	 * start consuming the list once we get XferNotReady

	 * IRQ.

	 *

	 * That way, we avoid doing anything that we don't need

	 * to do now and defer it until the point we receive a

	 * particular token from the Host side.

	 *

	 * This will also avoid Host cancelling URBs due to too

	 * many NAKs.

	 */

	ret = usb_gadget_map_request(&dwc->gadget, &req->request,

			dep->direction);

	if (ret)
@@ -1082,37 +1070,8 @@ static int __dwc3_gadget_ep_queue(struct dwc3_ep *dep, struct dwc3_request *req) 


	list_add_tail(&req->list, &dep->pending_list);



	/*

	 * If there are no pending requests and the endpoint isn't already

	 * busy, we will just start the request straight away.

	 *

	 * This will save one IRQ (XFER_NOT_READY) and possibly make it a

	 * little bit faster.

	 */

	if (!usb_endpoint_xfer_isoc(dep->endpoint.desc)) {

		ret = __dwc3_gadget_kick_transfer(dep, 0);

		goto out;

	}



	/*

	 * There are a few special cases:

	 *

	 * 1. XferNotReady with empty list of requests. We need to kick the

	 *    transfer here in that situation, otherwise we will be NAKing

	 *    forever. If we get XferNotReady before gadget driver has a

	 *    chance to queue a request, we will ACK the IRQ but won't be

	 *    able to receive the data until the next request is queued.

	 *    The following code is handling exactly that.

	 *

	 */

	if (dep->flags & DWC3_EP_PENDING_REQUEST) {

		/*

		 * If xfernotready is already elapsed and it is a case

		 * of isoc transfer, then issue END TRANSFER, so that

		 * you can receive xfernotready again and can have

		 * notion of current microframe.

		 */

		if (usb_endpoint_xfer_isoc(dep->endpoint.desc)) {

	if (usb_endpoint_xfer_isoc(dep->endpoint.desc) &&

			dep->flags & DWC3_EP_PENDING_REQUEST) {

		if (list_empty(&dep->started_list)) {

			dwc3_stop_active_transfer(dwc, dep->number, true);

			dep->flags = DWC3_EP_ENABLED;
@@ -1121,34 +1080,6 @@ static int __dwc3_gadget_ep_queue(struct dwc3_ep *dep, struct dwc3_request *req) 
	}



	ret = __dwc3_gadget_kick_transfer(dep, 0);

		if (!ret)

			dep->flags &= ~DWC3_EP_PENDING_REQUEST;



		goto out;

	}



	/*

	 * 2. XferInProgress on Isoc EP with an active transfer. We need to

	 *    kick the transfer here after queuing a request, otherwise the

	 *    core may not see the modified TRB(s).

	 */

	if (usb_endpoint_xfer_isoc(dep->endpoint.desc) &&

			(dep->flags & DWC3_EP_BUSY) &&

			!(dep->flags & DWC3_EP_MISSED_ISOC)) {

		WARN_ON_ONCE(!dep->resource_index);

		ret = __dwc3_gadget_kick_transfer(dep, dep->resource_index);

		goto out;

	}



	/*

	 * 4. Stream Capable Bulk Endpoints. We need to start the transfer

	 * right away, otherwise host will not know we have streams to be

	 * handled.

	 */

	if (dep->stream_capable)

		ret = __dwc3_gadget_kick_transfer(dep, 0);



out:

	if (ret && ret != -EBUSY)

		dwc3_trace(trace_dwc3_gadget,

				"%s: failed to kick transfers",