コード例 #1
0
/* Stop the current URB transfer */
void usb_stor_stop_transport(struct us_data *us)
{
	US_DEBUGP("%s called\n", __func__);

	/* If the state machine is blocked waiting for an URB,
	 * let's wake it up.  The test_and_clear_bit() call
	 * guarantees that if a URB has just been submitted,
	 * it won't be cancelled more than once. */
	if (test_and_clear_bit(US_FLIDX_URB_ACTIVE, &us->dflags)) {
		US_DEBUGP("-- cancelling URB\n");
		usb_unlink_urb(us->current_urb);
	}

	/* If we are waiting for a scatter-gather operation, cancel it. */
	if (test_and_clear_bit(US_FLIDX_SG_ACTIVE, &us->dflags)) {
		US_DEBUGP("-- cancelling sg request\n");
		usb_sg_cancel(&us->current_sg);
	}
}
コード例 #2
0
ファイル: transport.c プロジェクト: 020gzh/linux
/*
 * Transfer a scatter-gather list via bulk transfer
 *
 * This function does basically the same thing as usb_stor_bulk_transfer_buf()
 * above, but it uses the usbcore scatter-gather library.
 */
static int usb_stor_bulk_transfer_sglist(struct us_data *us, unsigned int pipe,
		struct scatterlist *sg, int num_sg, unsigned int length,
		unsigned int *act_len)
{
	int result;

	/* don't submit s-g requests during abort processing */
	if (test_bit(US_FLIDX_ABORTING, &us->dflags))
		return USB_STOR_XFER_ERROR;

	/* initialize the scatter-gather request block */
	usb_stor_dbg(us, "xfer %u bytes, %d entries\n", length, num_sg);
	result = usb_sg_init(&us->current_sg, us->pusb_dev, pipe, 0,
			sg, num_sg, length, GFP_NOIO);
	if (result) {
		usb_stor_dbg(us, "usb_sg_init returned %d\n", result);
		return USB_STOR_XFER_ERROR;
	}

	/* since the block has been initialized successfully, it's now
	 * okay to cancel it */
	set_bit(US_FLIDX_SG_ACTIVE, &us->dflags);

	/* did an abort occur during the submission? */
	if (test_bit(US_FLIDX_ABORTING, &us->dflags)) {

		/* cancel the request, if it hasn't been cancelled already */
		if (test_and_clear_bit(US_FLIDX_SG_ACTIVE, &us->dflags)) {
			usb_stor_dbg(us, "-- cancelling sg request\n");
			usb_sg_cancel(&us->current_sg);
		}
	}

	/* wait for the completion of the transfer */
	usb_sg_wait(&us->current_sg);
	clear_bit(US_FLIDX_SG_ACTIVE, &us->dflags);

	result = us->current_sg.status;
	if (act_len)
		*act_len = us->current_sg.bytes;
	return interpret_urb_result(us, pipe, length, result,
			us->current_sg.bytes);
}
コード例 #3
0
static int usb_stor_bulk_transfer_sglist(struct us_data *us, unsigned int pipe,
		struct scatterlist *sg, int num_sg, unsigned int length,
		unsigned int *act_len)
{
	int result;

	
	if (test_bit(US_FLIDX_ABORTING, &us->dflags))
		return USB_STOR_XFER_ERROR;

	
	US_DEBUGP("%s: xfer %u bytes, %d entries\n", __func__,
			length, num_sg);
	result = usb_sg_init(&us->current_sg, us->pusb_dev, pipe, 0,
			sg, num_sg, length, GFP_NOIO);
	if (result) {
		US_DEBUGP("usb_sg_init returned %d\n", result);
		return USB_STOR_XFER_ERROR;
	}

	set_bit(US_FLIDX_SG_ACTIVE, &us->dflags);

	
	if (test_bit(US_FLIDX_ABORTING, &us->dflags)) {

		
		if (test_and_clear_bit(US_FLIDX_SG_ACTIVE, &us->dflags)) {
			US_DEBUGP("-- cancelling sg request\n");
			usb_sg_cancel(&us->current_sg);
		}
	}

	
	usb_sg_wait(&us->current_sg);
	clear_bit(US_FLIDX_SG_ACTIVE, &us->dflags);

	result = us->current_sg.status;
	if (act_len)
		*act_len = us->current_sg.bytes;
	return interpret_urb_result(us, pipe, length, result,
			us->current_sg.bytes);
}
コード例 #4
0
ファイル: message.c プロジェクト: earthGavinLee/hg556a_source
/**
 * usb_sg_wait - synchronously execute scatter/gather request
 * @io: request block handle, as initialized with usb_sg_init().
 * 	some fields become accessible when this call returns.
 * Context: !in_interrupt ()
 *
 * This function blocks until the specified I/O operation completes.  It
 * leverages the grouping of the related I/O requests to get good transfer
 * rates, by queueing the requests.  At higher speeds, such queuing can
 * significantly improve USB throughput.
 *
 * There are three kinds of completion for this function.
 * (1) success, where io->status is zero.  The number of io->bytes
 *     transferred is as requested.
 * (2) error, where io->status is a negative errno value.  The number
 *     of io->bytes transferred before the error is usually less
 *     than requested, and can be nonzero.
 * (3) cancelation, a type of error with status -ECONNRESET that
 *     is initiated by usb_sg_cancel().
 *
 * When this function returns, all memory allocated through usb_sg_init() or
 * this call will have been freed.  The request block parameter may still be
 * passed to usb_sg_cancel(), or it may be freed.  It could also be
 * reinitialized and then reused.
 *
 * Data Transfer Rates:
 *
 * Bulk transfers are valid for full or high speed endpoints.
 * The best full speed data rate is 19 packets of 64 bytes each
 * per frame, or 1216 bytes per millisecond.
 * The best high speed data rate is 13 packets of 512 bytes each
 * per microframe, or 52 KBytes per millisecond.
 *
 * The reason to use interrupt transfers through this API would most likely
 * be to reserve high speed bandwidth, where up to 24 KBytes per millisecond
 * could be transferred.  That capability is less useful for low or full
 * speed interrupt endpoints, which allow at most one packet per millisecond,
 * of at most 8 or 64 bytes (respectively).
 */
void usb_sg_wait (struct usb_sg_request *io)
{
	int		i, entries = io->entries;

	/* queue the urbs.  */
	spin_lock_irq (&io->lock);
	for (i = 0; i < entries && !io->status; i++) {
		int	retval;

		io->urbs [i]->dev = io->dev;
		retval = usb_submit_urb (io->urbs [i], SLAB_ATOMIC);

		/* after we submit, let completions or cancelations fire;
		 * we handshake using io->status.
		 */
		spin_unlock_irq (&io->lock);
		switch (retval) {
			/* maybe we retrying will recover */
		case -ENXIO:	// hc didn't queue this one
		case -EAGAIN:
		case -ENOMEM:
			io->urbs[i]->dev = NULL;
			retval = 0;
			i--;
			yield ();
			break;

			/* no error? continue immediately.
			 *
			 * NOTE: to work better with UHCI (4K I/O buffer may
			 * need 3K of TDs) it may be good to limit how many
			 * URBs are queued at once; N milliseconds?
			 */
		case 0:
			cpu_relax ();
			break;

			/* fail any uncompleted urbs */
		default:
			spin_lock_irq (&io->lock);
			io->count -= entries - i;
			if (io->status == -EINPROGRESS)
				io->status = retval;
			if (io->count == 0)
				complete (&io->complete);
			spin_unlock_irq (&io->lock);

			io->urbs[i]->dev = NULL;
			io->urbs [i]->status = retval;
			dev_dbg (&io->dev->dev, "%s, submit --> %d\n",
				__FUNCTION__, retval);
			usb_sg_cancel (io);
		}
		spin_lock_irq (&io->lock);
		if (retval && io->status == -ECONNRESET)
			io->status = retval;
	}
	spin_unlock_irq (&io->lock);

	/* OK, yes, this could be packaged as non-blocking.
	 * So could the submit loop above ... but it's easier to
	 * solve neither problem than to solve both!
	 */
	wait_for_completion (&io->complete);

	sg_clean (io);
}