Commit d6e5a549 authored by Felipe Balbi's avatar Felipe Balbi
Browse files

usb: dwc3: simplify ZLP handling 



It's much simpler to just add one extra TRB chained to previous TRB to
handle ZLP. This helps us reduce pointless allocations and simplifies
the code a little bit.

Signed-off-by: default avatarFelipe Balbi <felipe.balbi@linux.intel.com>
parent 4199c5f8

drivers/usb/dwc3/core.h

+1 −3
Original line number Diff line number Diff line
@@ -40,7 +40,6 @@ 


/* Global constants */

#define DWC3_PULL_UP_TIMEOUT	500	/* ms */

#define DWC3_ZLP_BUF_SIZE	1024	/* size of a superspeed bulk */

#define DWC3_BOUNCE_SIZE	1024	/* size of a superspeed bulk */

#define DWC3_EP0_SETUP_SIZE	512

#define DWC3_ENDPOINTS_NUM	32
@@ -748,6 +747,7 @@ struct dwc3_request { 
	unsigned		direction:1;

	unsigned		mapped:1;

	unsigned		started:1;

	unsigned		zero:1;

};



/*
@@ -761,7 +761,6 @@ struct dwc3_scratchpad_array { 
/**

 * struct dwc3 - representation of our controller

 * @ep0_trb: trb which is used for the ctrl_req

 * @zlp_buf: used when request->zero is set

 * @setup_buf: used while precessing STD USB requests

 * @ep0_trb: dma address of ep0_trb

 * @ep0_usb_req: dummy req used while handling STD USB requests
@@ -857,7 +856,6 @@ struct dwc3_scratchpad_array { 
struct dwc3 {

	struct dwc3_trb		*ep0_trb;

	void			*bounce;

	void			*zlp_buf;

	void			*scratchbuf;

	u8			*setup_buf;

	dma_addr_t		ep0_trb_addr;

drivers/usb/dwc3/ep0.c

+29 −20
Original line number Diff line number Diff line
@@ -873,34 +873,19 @@ static void dwc3_ep0_complete_data(struct dwc3 *dwc, 
	transferred = ur->length - length;

	ur->actual += transferred;



	if (dwc->ep0_bounced) {

	if ((IS_ALIGNED(ur->length, ep0->endpoint.maxpacket) &&

	     ur->length && ur->zero) || dwc->ep0_bounced) {

		trb++;

		trb->ctrl &= ~DWC3_TRB_CTRL_HWO;

		trace_dwc3_complete_trb(ep0, trb);

		ep0->trb_enqueue = 0;

		dwc->ep0_bounced = false;

	}



	if ((epnum & 1) && ur->actual < ur->length) {

		/* for some reason we did not get everything out */



	if ((epnum & 1) && ur->actual < ur->length)

		dwc3_ep0_stall_and_restart(dwc);

	} else {

	else

		dwc3_gadget_giveback(ep0, r, 0);



		if (IS_ALIGNED(ur->length, ep0->endpoint.maxpacket) &&

				ur->length && ur->zero) {

			struct dwc3_ep *dep;

			int ret;



			dwc->ep0_next_event = DWC3_EP0_COMPLETE;



			dep = dwc->eps[epnum];

			dwc3_ep0_prepare_one_trb(dep, dwc->ep0_trb_addr,

					0, DWC3_TRBCTL_CONTROL_DATA, false);

			ret = dwc3_ep0_start_trans(dep);

			WARN_ON(ret < 0);

		}

	}

}



static void dwc3_ep0_complete_status(struct dwc3 *dwc,
@@ -1005,6 +990,30 @@ static void __dwc3_ep0_do_control_data(struct dwc3 *dwc, 
					 DWC3_TRBCTL_CONTROL_DATA,

					 false);

		ret = dwc3_ep0_start_trans(dep);

	} else if (IS_ALIGNED(req->request.length, dep->endpoint.maxpacket) &&

		   req->request.length && req->request.zero) {

		u32	maxpacket;

		u32	rem;



		ret = usb_gadget_map_request_by_dev(dwc->sysdev,

				&req->request, dep->number);

		if (ret)

			return;



		maxpacket = dep->endpoint.maxpacket;

		rem = req->request.length % maxpacket;



		/* prepare normal TRB */

		dwc3_ep0_prepare_one_trb(dep, req->request.dma,

					 req->request.length,

					 DWC3_TRBCTL_CONTROL_DATA,

					 true);



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

		dwc3_ep0_prepare_one_trb(dep, dwc->bounce_addr,

					 0, DWC3_TRBCTL_CONTROL_DATA,

					 false);

		ret = dwc3_ep0_start_trans(dep);

	} else {

		ret = usb_gadget_map_request_by_dev(dwc->sysdev,

				&req->request, dep->number);

drivers/usb/dwc3/gadget.c

+29 −60
Original line number Diff line number Diff line
@@ -1044,6 +1044,22 @@ static void dwc3_prepare_one_trb_linear(struct dwc3_ep *dep, 
				false, 0, req->request.stream_id,

				req->request.short_not_ok,

				req->request.no_interrupt);

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

		   (IS_ALIGNED(req->request.length,dep->endpoint.maxpacket))) {

		struct dwc3	*dwc = dep->dwc;

		struct dwc3_trb	*trb;



		req->zero = true;



		/* prepare normal TRB */

		dwc3_prepare_one_trb(dep, req, true, 0);



		/* Now prepare one extra TRB to handle ZLP */

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

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

				false, 0, req->request.stream_id,

				req->request.short_not_ok,

				req->request.no_interrupt);

	} else {

		dwc3_prepare_one_trb(dep, req, false, 0);

	}
@@ -1259,31 +1275,6 @@ static int __dwc3_gadget_ep_queue(struct dwc3_ep *dep, struct dwc3_request *req) 
	return ret;

}



static void __dwc3_gadget_ep_zlp_complete(struct usb_ep *ep,

		struct usb_request *request)

{

	dwc3_gadget_ep_free_request(ep, request);

}



static int __dwc3_gadget_ep_queue_zlp(struct dwc3 *dwc, struct dwc3_ep *dep)

{

	struct dwc3_request		*req;

	struct usb_request		*request;

	struct usb_ep			*ep = &dep->endpoint;



	request = dwc3_gadget_ep_alloc_request(ep, GFP_ATOMIC);

	if (!request)

		return -ENOMEM;



	request->length = 0;

	request->buf = dwc->zlp_buf;

	request->complete = __dwc3_gadget_ep_zlp_complete;



	req = to_dwc3_request(request);



	return __dwc3_gadget_ep_queue(dep, req);

}



static int dwc3_gadget_ep_queue(struct usb_ep *ep, struct usb_request *request,

	gfp_t gfp_flags)

{
@@ -1297,17 +1288,6 @@ static int dwc3_gadget_ep_queue(struct usb_ep *ep, struct usb_request *request, 


	spin_lock_irqsave(&dwc->lock, flags);

	ret = __dwc3_gadget_ep_queue(dep, req);



	/*

	 * Okay, here's the thing, if gadget driver has requested for a ZLP by

	 * setting request->zero, instead of doing magic, we will just queue an

	 * extra usb_request ourselves so that it gets handled the same way as

	 * any other request.

	 */

	if (ret == 0 && request->zero && request->length &&

	    (request->length % ep->maxpacket == 0))

		ret = __dwc3_gadget_ep_queue_zlp(dwc, dep);



	spin_unlock_irqrestore(&dwc->lock, flags);



	return ret;
@@ -1387,7 +1367,7 @@ static int dwc3_gadget_ep_dequeue(struct usb_ep *ep, 
					dwc3_ep_inc_deq(dep);

				}



				if (r->unaligned) {

				if (r->unaligned || r->zero) {

					trb = r->trb + r->num_pending_sgs + 1;

					trb->ctrl &= ~DWC3_TRB_CTRL_HWO;

					dwc3_ep_inc_deq(dep);
@@ -1398,7 +1378,7 @@ static int dwc3_gadget_ep_dequeue(struct usb_ep *ep, 
				trb->ctrl &= ~DWC3_TRB_CTRL_HWO;

				dwc3_ep_inc_deq(dep);



				if (r->unaligned) {

				if (r->unaligned || r->zero) {

					trb = r->trb + 1;

					trb->ctrl &= ~DWC3_TRB_CTRL_HWO;

					dwc3_ep_inc_deq(dep);
@@ -2164,7 +2144,7 @@ static int __dwc3_cleanup_done_trbs(struct dwc3 *dwc, struct dwc3_ep *dep, 
	 * with one TRB pending in the ring. We need to manually clear HWO bit

	 * from that TRB.

	 */

	if (req->unaligned && (trb->ctrl & DWC3_TRB_CTRL_HWO)) {

	if ((req->zero || req->unaligned) && (trb->ctrl & DWC3_TRB_CTRL_HWO)) {

		trb->ctrl &= ~DWC3_TRB_CTRL_HWO;

		return 1;

	}
@@ -2258,11 +2238,12 @@ static int dwc3_cleanup_done_reqs(struct dwc3 *dwc, struct dwc3_ep *dep, 
					event, status, chain);

		}



		if (req->unaligned) {

		if (req->unaligned || req->zero) {

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

			ret = __dwc3_cleanup_done_trbs(dwc, dep, req, trb,

					event, status, false);

			req->unaligned = false;

			req->zero = false;

		}



		req->request.actual = length - req->remaining;
@@ -3143,17 +3124,11 @@ int dwc3_gadget_init(struct dwc3 *dwc) 
		goto err1;

	}



	dwc->zlp_buf = kzalloc(DWC3_ZLP_BUF_SIZE, GFP_KERNEL);

	if (!dwc->zlp_buf) {

		ret = -ENOMEM;

		goto err2;

	}



	dwc->bounce = dma_alloc_coherent(dwc->sysdev, DWC3_BOUNCE_SIZE,

			&dwc->bounce_addr, GFP_KERNEL);

	if (!dwc->bounce) {

		ret = -ENOMEM;

		goto err3;

		goto err2;

	}



	init_completion(&dwc->ep0_in_setup);
@@ -3193,24 +3168,22 @@ int dwc3_gadget_init(struct dwc3 *dwc) 


	ret = dwc3_gadget_init_endpoints(dwc, dwc->num_eps);

	if (ret)

		goto err4;

		goto err3;



	ret = usb_add_gadget_udc(dwc->dev, &dwc->gadget);

	if (ret) {

		dev_err(dwc->dev, "failed to register udc\n");

		goto err5;

		goto err4;

	}



	return 0;

err5:

	dwc3_gadget_free_endpoints(dwc);



err4:

	dma_free_coherent(dwc->sysdev, DWC3_BOUNCE_SIZE, dwc->bounce,

			dwc->bounce_addr);

	dwc3_gadget_free_endpoints(dwc);



err3:

	kfree(dwc->zlp_buf);

	dma_free_coherent(dwc->sysdev, DWC3_BOUNCE_SIZE, dwc->bounce,

			dwc->bounce_addr);



err2:

	kfree(dwc->setup_buf);
@@ -3228,14 +3201,10 @@ err0: 
void dwc3_gadget_exit(struct dwc3 *dwc)

{

	usb_del_gadget_udc(&dwc->gadget);



	dwc3_gadget_free_endpoints(dwc);



	dma_free_coherent(dwc->sysdev, DWC3_BOUNCE_SIZE, dwc->bounce,

			  dwc->bounce_addr);

	kfree(dwc->setup_buf);

	kfree(dwc->zlp_buf);



	dma_free_coherent(dwc->sysdev, sizeof(*dwc->ep0_trb) * 2,

			  dwc->ep0_trb, dwc->ep0_trb_addr);

}