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Commit f898ae09 authored by Paul Zimmerman's avatar Paul Zimmerman Committed by Felipe Balbi
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usb: dwc3: gadget: issue Update Transfer command after queuing isoc request 



Issue an Update Transfer command after queuing a request to an isoc
EP with an active transfer. This is required according to the dwc3
databook. Pratyush Anand reports that this fixes a problem he was
having with Isoc IN transfers.

Tested-by: default avatarPratyush <Anand&lt;pratyush.anand@st.com>
Signed-off-by: default avatarPaul Zimmerman <paulz@synopsys.com>
Signed-off-by: default avatarFelipe Balbi <balbi@ti.com>
parent c12a0d86

drivers/usb/dwc3/gadget.c

+28 −17
Original line number Diff line number Diff line
@@ -957,10 +957,12 @@ static int __dwc3_gadget_kick_transfer(struct dwc3_ep *dep, u16 cmd_param, 
	}



	dep->flags |= DWC3_EP_BUSY;



	if (start_new) {

		dep->res_trans_idx = dwc3_gadget_ep_get_transfer_index(dwc,

				dep->number);



		WARN_ON_ONCE(!dep->res_trans_idx);

	}



	return 0;

}
@@ -994,28 +996,37 @@ static int __dwc3_gadget_ep_queue(struct dwc3_ep *dep, struct dwc3_request *req) 


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



	if (usb_endpoint_xfer_isoc(dep->desc) && (dep->flags & DWC3_EP_BUSY))

		dep->flags |= DWC3_EP_PENDING_REQUEST;



	/*

	 * There is one special case: XferNotReady with

	 * empty list of requests. We need to kick the

	 * transfer here in that situation, otherwise

	 * we will be NAKing forever.

	 * There are two 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 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.

	 * 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 (dep->flags & DWC3_EP_PENDING_REQUEST) {

		int	ret;

		int start_trans;

		int	start_trans = 1;

		u8	trans_idx = dep->res_trans_idx;



		start_trans = 1;

		if (usb_endpoint_xfer_isoc(dep->desc) &&

				(dep->flags & DWC3_EP_BUSY))

				(dep->flags & DWC3_EP_BUSY)) {

			start_trans = 0;

			WARN_ON_ONCE(!trans_idx);

		} else {

			trans_idx = 0;

		}



		ret = __dwc3_gadget_kick_transfer(dep, 0, start_trans);

		ret = __dwc3_gadget_kick_transfer(dep, trans_idx, start_trans);

		if (ret && ret != -EBUSY) {

			struct dwc3	*dwc = dep->dwc;