Commit 249f0a25 authored by Peter Chen's avatar Peter Chen Committed by Felipe Balbi
Browse files

usb: cdns3: gadget: handle sg list use case at completion correctly 



- Judge each TRB has been handled at cdns3_trb_handled, since
the DMA pointer may be at the middle of the TD, we can't consider
this TD has finished at that time.
- Calculate req->actual according to finished TRBs.
- Handle short transfer for sg list use case correctly. When the
short transfer occurs, we check OUT_SMM at TRB to see if it is
the last TRB.

Signed-off-by: default avatarPeter Chen <peter.chen@nxp.com>
Signed-off-by: default avatarFelipe Balbi <balbi@kernel.org>
parent 87e1dcd4

drivers/usb/cdns3/gadget.c

+56 −29
Original line number Diff line number Diff line
@@ -817,6 +817,8 @@ void cdns3_gadget_giveback(struct cdns3_endpoint *priv_ep, 
		       request->length);



	priv_req->flags &= ~(REQUEST_PENDING | REQUEST_UNALIGNED);

	/* All TRBs have finished, clear the counter */

	priv_req->finished_trb = 0;

	trace_cdns3_gadget_giveback(priv_req);



	if (priv_dev->dev_ver < DEV_VER_V2) {
@@ -1239,6 +1241,7 @@ static int cdns3_ep_run_transfer(struct cdns3_endpoint *priv_ep, 
	trb = priv_req->trb;



	priv_req->flags |= REQUEST_PENDING;

	priv_req->num_of_trb = num_trb;



	if (sg_iter == 1)

		trb->control |= cpu_to_le32(TRB_IOC | TRB_ISP);
@@ -1360,7 +1363,7 @@ void cdns3_set_hw_configuration(struct cdns3_device *priv_dev) 
}



/**

 * cdns3_request_handled - check whether request has been handled by DMA

 * cdns3_trb_handled - check whether trb has been handled by DMA

 *

 * @priv_ep: extended endpoint object.

 * @priv_req: request object for checking
@@ -1377,32 +1380,28 @@ void cdns3_set_hw_configuration(struct cdns3_device *priv_dev) 
 * ET = priv_req->end_trb - index of last TRB in transfer ring

 * CI = current_index - index of processed TRB by DMA.

 *

 * As first step, function checks if cycle bit for priv_req->start_trb is

 * correct.

 * As first step, we check if the TRB between the ST and ET.

 * Then, we check if cycle bit for index priv_ep->dequeue

 * is correct.

 *

 * some rules:

 * 1. priv_ep->dequeue never exceed current_index.

 * 1. priv_ep->dequeue never equals to current_index.

 * 2  priv_ep->enqueue never exceed priv_ep->dequeue

 * 3. exception: priv_ep->enqueue == priv_ep->dequeue

 *    and priv_ep->free_trbs is zero.

 *    This case indicate that TR is full.

 *

 * Then We can split recognition into two parts:

 * At below two cases, the request have been handled.

 * Case 1 - priv_ep->dequeue < current_index

 *      SR ... EQ ... DQ ... CI ... ER

 *      SR ... DQ ... CI ... EQ ... ER

 *

 *      Request has been handled by DMA if ST and ET is between DQ and CI.

 *

 * Case 2 - priv_ep->dequeue > current_index

 * This situation take place when CI go through the LINK TRB at the end of

 * This situation takes place when CI go through the LINK TRB at the end of

 * transfer ring.

 *      SR ... CI ... EQ ... DQ ... ER

 *

 *      Request has been handled by DMA if ET is less then CI or

 *      ET is greater or equal DQ.

 */

static bool cdns3_request_handled(struct cdns3_endpoint *priv_ep,

static bool cdns3_trb_handled(struct cdns3_endpoint *priv_ep,

				  struct cdns3_request *priv_req)

{

	struct cdns3_device *priv_dev = priv_ep->cdns3_dev;
@@ -1414,7 +1413,25 @@ static bool cdns3_request_handled(struct cdns3_endpoint *priv_ep, 
	current_index = cdns3_get_dma_pos(priv_dev, priv_ep);

	doorbell = !!(readl(&priv_dev->regs->ep_cmd) & EP_CMD_DRDY);



	trb = &priv_ep->trb_pool[priv_req->start_trb];

	/* current trb doesn't belong to this request */

	if (priv_req->start_trb < priv_req->end_trb) {

		if (priv_ep->dequeue > priv_req->end_trb)

			goto finish;



		if (priv_ep->dequeue < priv_req->start_trb)

			goto finish;

	}



	if ((priv_req->start_trb > priv_req->end_trb) &&

		(priv_ep->dequeue > priv_req->end_trb) &&

		(priv_ep->dequeue < priv_req->start_trb))

		goto finish;



	if ((priv_req->start_trb == priv_req->end_trb) &&

		(priv_ep->dequeue != priv_req->end_trb))

		goto finish;



	trb = &priv_ep->trb_pool[priv_ep->dequeue];



	if ((le32_to_cpu(trb->control) & TRB_CYCLE) != priv_ep->ccs)

		goto finish;
@@ -1436,12 +1453,8 @@ static bool cdns3_request_handled(struct cdns3_endpoint *priv_ep, 
		    !priv_ep->dequeue)

			goto finish;



		if (priv_req->end_trb >= priv_ep->dequeue &&

		    priv_req->end_trb < current_index)

		handled = 1;

	} else if (priv_ep->dequeue  > current_index) {

		if (priv_req->end_trb  < current_index ||

		    priv_req->end_trb >= priv_ep->dequeue)

			handled = 1;

	}
@@ -1457,6 +1470,8 @@ static void cdns3_transfer_completed(struct cdns3_device *priv_dev, 
	struct cdns3_request *priv_req;

	struct usb_request *request;

	struct cdns3_trb *trb;

	bool request_handled = false;

	bool transfer_end = false;



	while (!list_empty(&priv_ep->pending_req_list)) {

		request = cdns3_next_request(&priv_ep->pending_req_list);
@@ -1476,20 +1491,32 @@ static void cdns3_transfer_completed(struct cdns3_device *priv_dev, 
			 */

			cdns3_select_ep(priv_dev, priv_ep->endpoint.address);



			if (!cdns3_request_handled(priv_ep, priv_req))

				goto prepare_next_td;

			while (cdns3_trb_handled(priv_ep, priv_req)) {

				priv_req->finished_trb++;

				if (priv_req->finished_trb >= priv_req->num_of_trb)

					request_handled = true;



				trb = priv_ep->trb_pool + priv_ep->dequeue;

				trace_cdns3_complete_trb(priv_ep, trb);



			if (trb != priv_req->trb)

				dev_warn(priv_dev->dev,

					 "request_trb=0x%p, queue_trb=0x%p\n",

					 priv_req->trb, trb);

				if (!transfer_end)

					request->actual +=

						TRB_LEN(le32_to_cpu(trb->length));



			request->actual = TRB_LEN(le32_to_cpu(trb->length));

			cdns3_move_deq_to_next_trb(priv_req);

				if (priv_req->num_of_trb > 1 &&

					le32_to_cpu(trb->control) & TRB_SMM)

					transfer_end = true;



				cdns3_ep_inc_deq(priv_ep);

			}



			if (request_handled) {

				cdns3_gadget_giveback(priv_ep, priv_req, 0);

				request_handled = false;

				transfer_end = false;

			} else {

				goto prepare_next_td;

			}



			if (priv_ep->type != USB_ENDPOINT_XFER_ISOC &&

			    TRBS_PER_SEGMENT == 2)

drivers/usb/cdns3/gadget.h

+9 −0
Original line number Diff line number Diff line
@@ -1030,6 +1030,11 @@ struct cdns3_trb { 
 * When set to '1', the device will toggle its interpretation of the Cycle bit

 */

#define TRB_TOGGLE		BIT(1)

/*

 * The controller will set it if OUTSMM (OUT size mismatch) is detected,

 * this bit is for normal TRB

 */

#define TRB_SMM			BIT(1)



/*

 * Short Packet (SP). OUT EPs at DMULT=1 only. Indicates if the TRB was
@@ -1215,6 +1220,8 @@ struct cdns3_aligned_buf { 
 *               this endpoint

 * @flags: flag specifying special usage of request

 * @list: used by internally allocated request to add to wa2_descmiss_req_list.

 * @finished_trb: number of trb has already finished per request

 * @num_of_trb: how many trbs in this request

 */

struct cdns3_request {

	struct usb_request		request;
@@ -1230,6 +1237,8 @@ struct cdns3_request { 
#define REQUEST_UNALIGNED		BIT(4)

	u32				flags;

	struct list_head		list;

	int				finished_trb;

	int				num_of_trb;

};



#define to_cdns3_request(r) (container_of(r, struct cdns3_request, request))

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