Commit 2b80357b authored by Thinh Nguyen's avatar Thinh Nguyen Committed by Felipe Balbi
Browse files

usb: dwc3: gadget: Refactor preparing extra TRB 



When the driver prepares the extra TRB, it uses bounce buffer. If we
just add a new parameter to dwc3_prepare_one_trb() to indicate this,
then we can refactor and simplify the driver quite a bit.
dwc3_prepare_one_trb() also checks if a request had been moved to the
started list. This is a prerequisite to subsequence patches improving
the handling of extra TRBs.

Signed-off-by: default avatarThinh Nguyen <Thinh.Nguyen@synopsys.com>
Signed-off-by: default avatarFelipe Balbi <balbi@kernel.org>
parent 690e5c2d

drivers/usb/dwc3/gadget.c

+25 −68
Original line number Diff line number Diff line
@@ -1060,10 +1060,11 @@ static void __dwc3_prepare_one_trb(struct dwc3_ep *dep, struct dwc3_trb *trb, 
 * @trb_length: buffer size of the TRB

 * @chain: should this TRB be chained to the next?

 * @node: only for isochronous endpoints. First TRB needs different type.

 * @use_bounce_buffer: set to use bounce buffer

 */

static void dwc3_prepare_one_trb(struct dwc3_ep *dep,

		struct dwc3_request *req, unsigned int trb_length,

		unsigned int chain, unsigned int node)

		unsigned int chain, unsigned int node, bool use_bounce_buffer)

{

	struct dwc3_trb		*trb;

	dma_addr_t		dma;
@@ -1072,7 +1073,9 @@ static void dwc3_prepare_one_trb(struct dwc3_ep *dep, 
	unsigned int		no_interrupt = req->request.no_interrupt;

	unsigned int		is_last = req->request.is_last;



	if (req->request.num_sgs > 0)

	if (use_bounce_buffer)

		dma = dep->dwc->bounce_addr;

	else if (req->request.num_sgs > 0)

		dma = sg_dma_address(req->start_sg);

	else

		dma = req->request.dma;
@@ -1129,56 +1132,35 @@ static void dwc3_prepare_one_trb_sg(struct dwc3_ep *dep, 
			chain = false;



		if (rem && usb_endpoint_dir_out(dep->endpoint.desc) && !chain) {

			struct dwc3	*dwc = dep->dwc;

			struct dwc3_trb	*trb;



			req->needs_extra_trb = true;



			/* prepare normal TRB */

			dwc3_prepare_one_trb(dep, req, trb_length, true, i);

			dwc3_prepare_one_trb(dep, req, trb_length,

					true, i, false);



			/* Now prepare one extra TRB to align transfer size */

			trb = &dep->trb_pool[dep->trb_enqueue];

			req->num_trbs++;

			__dwc3_prepare_one_trb(dep, trb, dwc->bounce_addr,

					maxp - rem, false, 1,

					req->request.stream_id,

					req->request.short_not_ok,

					req->request.no_interrupt,

					req->request.is_last);

			dwc3_prepare_one_trb(dep, req, maxp - rem,

					false, 1, true);

		} else if (req->request.zero && req->request.length &&

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

			   !rem && !chain) {

			struct dwc3	*dwc = dep->dwc;

			struct dwc3_trb	*trb;



			req->needs_extra_trb = true;



			/* Prepare normal TRB */

			dwc3_prepare_one_trb(dep, req, trb_length, true, i);

			dwc3_prepare_one_trb(dep, req, trb_length,

					true, i, false);



			/* Prepare one extra TRB to handle ZLP */

			trb = &dep->trb_pool[dep->trb_enqueue];

			req->num_trbs++;

			__dwc3_prepare_one_trb(dep, trb, dwc->bounce_addr, 0,

					       !req->direction, 1,

					       req->request.stream_id,

					       req->request.short_not_ok,

					       req->request.no_interrupt,

					       req->request.is_last);

			dwc3_prepare_one_trb(dep, req, 0,

					!req->direction, 1, true);



			/* Prepare one more TRB to handle MPS alignment */

			if (!req->direction) {

				trb = &dep->trb_pool[dep->trb_enqueue];

				req->num_trbs++;

				__dwc3_prepare_one_trb(dep, trb, dwc->bounce_addr, maxp,

						       false, 1, req->request.stream_id,

						       req->request.short_not_ok,

						       req->request.no_interrupt,

						       req->request.is_last);

			}

			if (!req->direction)

				dwc3_prepare_one_trb(dep, req, maxp,

						false, 1, true);

		} else {

			dwc3_prepare_one_trb(dep, req, trb_length, chain, i);

			dwc3_prepare_one_trb(dep, req, trb_length,

					chain, i, false);

		}



		/*
@@ -1216,54 +1198,29 @@ static void dwc3_prepare_one_trb_linear(struct dwc3_ep *dep, 
	unsigned int rem = length % maxp;



	if ((!length || rem) && usb_endpoint_dir_out(dep->endpoint.desc)) {

		struct dwc3	*dwc = dep->dwc;

		struct dwc3_trb	*trb;



		req->needs_extra_trb = true;



		/* prepare normal TRB */

		dwc3_prepare_one_trb(dep, req, length, true, 0);

		dwc3_prepare_one_trb(dep, req, length, true, 0, false);



		/* Now prepare one extra TRB to align transfer size */

		trb = &dep->trb_pool[dep->trb_enqueue];

		req->num_trbs++;

		__dwc3_prepare_one_trb(dep, trb, dwc->bounce_addr, maxp - rem,

				false, 1, req->request.stream_id,

				req->request.short_not_ok,

				req->request.no_interrupt,

				req->request.is_last);

		dwc3_prepare_one_trb(dep, req, maxp - rem, false, 1, true);

	} else if (req->request.zero && req->request.length &&

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

		   (IS_ALIGNED(req->request.length, maxp))) {

		struct dwc3	*dwc = dep->dwc;

		struct dwc3_trb	*trb;



		req->needs_extra_trb = true;



		/* prepare normal TRB */

		dwc3_prepare_one_trb(dep, req, length, true, 0);

		dwc3_prepare_one_trb(dep, req, length, true, 0, false);



		/* Prepare one extra TRB to handle ZLP */

		trb = &dep->trb_pool[dep->trb_enqueue];

		req->num_trbs++;

		__dwc3_prepare_one_trb(dep, trb, dwc->bounce_addr, 0,

				!req->direction, 1, req->request.stream_id,

				req->request.short_not_ok,

				req->request.no_interrupt,

				req->request.is_last);

		dwc3_prepare_one_trb(dep, req, 0, !req->direction, 1, true);



		/* Prepare one more TRB to handle MPS alignment for OUT */

		if (!req->direction) {

			trb = &dep->trb_pool[dep->trb_enqueue];

			req->num_trbs++;

			__dwc3_prepare_one_trb(dep, trb, dwc->bounce_addr, maxp,

					       false, 1, req->request.stream_id,

					       req->request.short_not_ok,

					       req->request.no_interrupt,

					       req->request.is_last);

		}

		if (!req->direction)

			dwc3_prepare_one_trb(dep, req, maxp, false, 1, true);

	} else {

		dwc3_prepare_one_trb(dep, req, length, false, 0);

		dwc3_prepare_one_trb(dep, req, length, false, 0, false);

	}

}

CRA Git | Maintained and supported by SUSTech CRA and CCSE