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Commit 7d24c1b5 authored by Mian Yousaf Kaukab's avatar Mian Yousaf Kaukab Committed by Felipe Balbi
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usb: dwc2: gadget: add unaligned buffers support 



When using DMA, dwc2 requires buffers to be 4 bytes aligned. Use
bounce buffers if they are not.

Tested-by: default avatarRobert Baldyga <r.baldyga@samsung.com>
Acked-by: default avatarJohn Youn <johnyoun@synopsys.com>
Signed-off-by: default avatarMian Yousaf Kaukab <yousaf.kaukab@intel.com>
Signed-off-by: default avatarFelipe Balbi <balbi@ti.com>
parent d7c747c5

drivers/usb/dwc2/core.h

+2 −0
Original line number Diff line number Diff line
@@ -158,10 +158,12 @@ struct s3c_hsotg_ep { 
 * struct s3c_hsotg_req - data transfer request

 * @req: The USB gadget request

 * @queue: The list of requests for the endpoint this is queued for.

 * @saved_req_buf: variable to save req.buf when bounce buffers are used.

 */

struct s3c_hsotg_req {

	struct usb_request      req;

	struct list_head        queue;

	void *saved_req_buf;

};



#if IS_ENABLED(CONFIG_USB_DWC2_PERIPHERAL) || IS_ENABLED(CONFIG_USB_DWC2_DUAL_ROLE)

drivers/usb/dwc2/gadget.c

+61 −1
Original line number Diff line number Diff line
@@ -726,6 +726,59 @@ static int s3c_hsotg_map_dma(struct dwc2_hsotg *hsotg, 
	return -EIO;

}



static int s3c_hsotg_handle_unaligned_buf_start(struct dwc2_hsotg *hsotg,

	struct s3c_hsotg_ep *hs_ep, struct s3c_hsotg_req *hs_req)

{

	void *req_buf = hs_req->req.buf;



	/* If dma is not being used or buffer is aligned */

	if (!using_dma(hsotg) || !((long)req_buf & 3))

		return 0;



	WARN_ON(hs_req->saved_req_buf);



	dev_dbg(hsotg->dev, "%s: %s: buf=%p length=%d\n", __func__,

			hs_ep->ep.name, req_buf, hs_req->req.length);



	hs_req->req.buf = kmalloc(hs_req->req.length, GFP_ATOMIC);

	if (!hs_req->req.buf) {

		hs_req->req.buf = req_buf;

		dev_err(hsotg->dev,

			"%s: unable to allocate memory for bounce buffer\n",

			__func__);

		return -ENOMEM;

	}



	/* Save actual buffer */

	hs_req->saved_req_buf = req_buf;



	if (hs_ep->dir_in)

		memcpy(hs_req->req.buf, req_buf, hs_req->req.length);

	return 0;

}



static void s3c_hsotg_handle_unaligned_buf_complete(struct dwc2_hsotg *hsotg,

	struct s3c_hsotg_ep *hs_ep, struct s3c_hsotg_req *hs_req)

{

	/* If dma is not being used or buffer was aligned */

	if (!using_dma(hsotg) || !hs_req->saved_req_buf)

		return;



	dev_dbg(hsotg->dev, "%s: %s: status=%d actual-length=%d\n", __func__,

		hs_ep->ep.name, hs_req->req.status, hs_req->req.actual);



	/* Copy data from bounce buffer on successful out transfer */

	if (!hs_ep->dir_in && !hs_req->req.status)

		memcpy(hs_req->saved_req_buf, hs_req->req.buf,

							hs_req->req.actual);



	/* Free bounce buffer */

	kfree(hs_req->req.buf);



	hs_req->req.buf = hs_req->saved_req_buf;

	hs_req->saved_req_buf = NULL;

}



static int s3c_hsotg_ep_queue(struct usb_ep *ep, struct usb_request *req,

			      gfp_t gfp_flags)

{
@@ -733,6 +786,7 @@ static int s3c_hsotg_ep_queue(struct usb_ep *ep, struct usb_request *req, 
	struct s3c_hsotg_ep *hs_ep = our_ep(ep);

	struct dwc2_hsotg *hs = hs_ep->parent;

	bool first;

	int ret;



	dev_dbg(hs->dev, "%s: req %p: %d@%p, noi=%d, zero=%d, snok=%d\n",

		ep->name, req, req->length, req->buf, req->no_interrupt,
@@ -743,9 +797,13 @@ static int s3c_hsotg_ep_queue(struct usb_ep *ep, struct usb_request *req, 
	req->actual = 0;

	req->status = -EINPROGRESS;



	ret = s3c_hsotg_handle_unaligned_buf_start(hs, hs_ep, hs_req);

	if (ret)

		return ret;



	/* if we're using DMA, sync the buffers as necessary */

	if (using_dma(hs)) {

		int ret = s3c_hsotg_map_dma(hs, hs_ep, req);

		ret = s3c_hsotg_map_dma(hs, hs_ep, req);

		if (ret)

			return ret;

	}
@@ -1326,6 +1384,8 @@ static void s3c_hsotg_complete_request(struct dwc2_hsotg *hsotg, 
	if (hs_req->req.status == -EINPROGRESS)

		hs_req->req.status = result;



	s3c_hsotg_handle_unaligned_buf_complete(hsotg, hs_ep, hs_req);



	hs_ep->req = NULL;

	list_del_init(&hs_req->queue);