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Commit 5ee85d89 authored by Felipe Balbi's avatar Felipe Balbi
Browse files

usb: dwc3: gadget: split __dwc3_gadget_kick_transfer() 



To aid code readability, we're gonna split
__dwc3_gadget_kick_transfer() into its constituent
parts: scatter gather and linear buffers.

That way, it's easier to follow the code and focus
debug effort when one or the other fails.

Signed-off-by: default avatarFelipe Balbi <felipe.balbi@linux.intel.com>
parent 6b742899

drivers/usb/dwc3/gadget.c

+65 −57
Original line number Diff line number Diff line
@@ -903,33 +903,15 @@ static u32 dwc3_calc_trbs_left(struct dwc3_ep *dep) 
	return dep->trb_dequeue - dep->trb_enqueue;

}



/*

 * dwc3_prepare_trbs - setup TRBs from requests

 * @dep: endpoint for which requests are being prepared

 *

 * The function goes through the requests list and sets up TRBs for the

 * transfers. The function returns once there are no more TRBs available or

 * it runs out of requests.

 */

static void dwc3_prepare_trbs(struct dwc3_ep *dep)

static void dwc3_prepare_one_trb_sg(struct dwc3_ep *dep,

		struct dwc3_request *req, unsigned int trbs_left)

{

	struct dwc3_request	*req, *n;

	u32			trbs_left;

	unsigned int		last_one = 0;



	BUILD_BUG_ON_NOT_POWER_OF_2(DWC3_TRB_NUM);



	trbs_left = dwc3_calc_trbs_left(dep);



	list_for_each_entry_safe(req, n, &dep->pending_list, list) {

		unsigned	length;

		dma_addr_t	dma;

		last_one = false;



		if (req->request.num_mapped_sgs > 0) {

	struct usb_request *request = &req->request;

	struct scatterlist *sg = request->sg;

	struct scatterlist *s;

	unsigned int	last = false;

	unsigned int	length;

	dma_addr_t	dma;

	int		i;



	for_each_sg(sg, s, request->num_mapped_sgs, i) {
@@ -940,45 +922,71 @@ static void dwc3_prepare_trbs(struct dwc3_ep *dep) 


		if (sg_is_last(s)) {

			if (list_is_last(&req->list, &dep->pending_list))

						last_one = true;

				last = true;



			chain = false;

		}



				trbs_left--;

		if (!trbs_left)

					last_one = true;

			last = true;



				if (last_one)

		if (last)

			chain = false;



		dwc3_prepare_one_trb(dep, req, dma, length,

						last_one, chain, i);

				last, chain, i);



				if (last_one)

		if (last)

			break;

	}

}



static void dwc3_prepare_one_trb_linear(struct dwc3_ep *dep,

		struct dwc3_request *req, unsigned int trbs_left)

{

	unsigned int	last = false;

	unsigned int	length;

	dma_addr_t	dma;



			if (last_one)

				break;

		} else {

	dma = req->request.dma;

	length = req->request.length;

			trbs_left--;



	if (!trbs_left)

				last_one = true;

		last = true;



	/* Is this the last request? */

	if (list_is_last(&req->list, &dep->pending_list))

				last_one = true;

		last = true;



	dwc3_prepare_one_trb(dep, req, dma, length,

					last_one, false, 0);



			if (last_one)

				break;

			last, false, 0);

}



/*

 * dwc3_prepare_trbs - setup TRBs from requests

 * @dep: endpoint for which requests are being prepared

 *

 * The function goes through the requests list and sets up TRBs for the

 * transfers. The function returns once there are no more TRBs available or

 * it runs out of requests.

 */

static void dwc3_prepare_trbs(struct dwc3_ep *dep)

{

	struct dwc3_request	*req, *n;

	u32			trbs_left;



	BUILD_BUG_ON_NOT_POWER_OF_2(DWC3_TRB_NUM);



	trbs_left = dwc3_calc_trbs_left(dep);



	list_for_each_entry_safe(req, n, &dep->pending_list, list) {

		if (req->request.num_mapped_sgs > 0)

			dwc3_prepare_one_trb_sg(dep, req, trbs_left--);

		else

			dwc3_prepare_one_trb_linear(dep, req, trbs_left--);



		if (!trbs_left)

			return;

	}

}