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Commit 14fce33a authored by Sebastian Andrzej Siewior's avatar Sebastian Andrzej Siewior Committed by Felipe Balbi
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usb: gadget: dummy_hcd: add sg support 



This patch adds sg support to dummy_hcd. It seems that uas is not able
to work with a hcd which does not support sg only based transfers.

Signed-off-by: default avatarSebastian Andrzej Siewior <bigeasy@linutronix.de>
Acked-by: default avatarAlan Stern <stern@rowland.harvard.edu>
Signed-off-by: default avatarFelipe Balbi <balbi@ti.com>
parent a04ce20d

drivers/usb/gadget/dummy_hcd.c

+67 −13
Original line number Diff line number Diff line
@@ -39,6 +39,7 @@ 
#include <linux/usb.h>

#include <linux/usb/gadget.h>

#include <linux/usb/hcd.h>

#include <linux/scatterlist.h>



#include <asm/byteorder.h>

#include <asm/io.h>
@@ -147,6 +148,8 @@ static const char *const ep_name [] = { 
struct urbp {

	struct urb		*urb;

	struct list_head	urbp_list;

	struct sg_mapping_iter	miter;

	u32			miter_started;

};
@@ -1077,13 +1080,11 @@ static int dummy_urb_enqueue ( 
	unsigned long	flags;

	int		rc;



	if (!urb->transfer_buffer && urb->transfer_buffer_length)

		return -EINVAL;



	urbp = kmalloc (sizeof *urbp, mem_flags);

	if (!urbp)

		return -ENOMEM;

	urbp->urb = urb;

	urbp->miter_started = 0;



	dum_hcd = hcd_to_dummy_hcd(hcd);

	spin_lock_irqsave(&dum_hcd->dum->lock, flags);
@@ -1137,12 +1138,18 @@ static int dummy_perform_transfer(struct urb *urb, struct dummy_request *req, 
		u32 len)

{

	void *ubuf, *rbuf;

	struct urbp *urbp = urb->hcpriv;

	int to_host;

	struct sg_mapping_iter *miter = &urbp->miter;

	u32 trans = 0;

	u32 this_sg;

	bool next_sg;



	to_host = usb_pipein(urb->pipe);

	rbuf = req->req.buf + req->req.actual;

	ubuf = urb->transfer_buffer + urb->actual_length;



	if (!urb->num_sgs) {

		ubuf = urb->transfer_buffer + urb->actual_length;

		if (to_host)

			memcpy(ubuf, rbuf, len);

		else
@@ -1150,6 +1157,49 @@ static int dummy_perform_transfer(struct urb *urb, struct dummy_request *req, 
		return len;

	}



	if (!urbp->miter_started) {

		u32 flags = SG_MITER_ATOMIC;



		if (to_host)

			flags |= SG_MITER_TO_SG;

		else

			flags |= SG_MITER_FROM_SG;



		sg_miter_start(miter, urb->sg, urb->num_sgs, flags);

		urbp->miter_started = 1;

	}

	next_sg = sg_miter_next(miter);

	if (next_sg == false) {

		WARN_ON_ONCE(1);

		return -EINVAL;

	}

	do {

		ubuf = miter->addr;

		this_sg = min_t(u32, len, miter->length);

		miter->consumed = this_sg;

		trans += this_sg;



		if (to_host)

			memcpy(ubuf, rbuf, this_sg);

		else

			memcpy(rbuf, ubuf, this_sg);

		len -= this_sg;



		if (!len)

			break;

		next_sg = sg_miter_next(miter);

		if (next_sg == false) {

			WARN_ON_ONCE(1);

			return -EINVAL;

		}



		rbuf += this_sg;

	} while (1);



	sg_miter_stop(miter);

	return trans;

}



/* transfer up to a frame's worth; caller must own lock */

static int

transfer(struct dummy *dum, struct urb *urb, struct dummy_ep *ep, int limit,
@@ -1198,11 +1248,14 @@ top: 
			len = dummy_perform_transfer(urb, req, len);



			ep->last_io = jiffies;



			if (len < 0) {

				req->req.status = len;

			} else {

				limit -= len;

				urb->actual_length += len;

				req->req.actual += len;

			}

		}



		/* short packets terminate, maybe with overflow/underflow.

		 * it's only really an error to write too much.
@@ -2212,6 +2265,7 @@ static int dummy_h_get_frame (struct usb_hcd *hcd) 


static int dummy_setup(struct usb_hcd *hcd)

{

	hcd->self.sg_tablesize = ~0;

	if (usb_hcd_is_primary_hcd(hcd)) {

		the_controller.hs_hcd = hcd_to_dummy_hcd(hcd);

		the_controller.hs_hcd->dum = &the_controller;