uhci-hcd.c

h内核

			data);

		data += pktsze;
		len -= maxsze;

		usb_dotoggle(urb->dev, usb_pipeendpoint(urb->pipe),
			usb_pipeout(urb->pipe));
	} while (len > 0);

	/*
	 * URB_ZERO_PACKET means adding a 0-length packet, if direction
	 * is OUT and the transfer_length was an exact multiple of maxsze,
	 * hence (len = transfer_length - N * maxsze) == 0
	 * however, if transfer_length == 0, the zero packet was already
	 * prepared above.
	 */
	if (usb_pipeout(urb->pipe) && (urb->transfer_flags & URB_ZERO_PACKET) &&
	    !len && urb->transfer_buffer_length) {
		td = uhci_alloc_td(uhci, urb->dev);
		if (!td)
			return -ENOMEM;

		uhci_add_td_to_urb(urb, td);
		uhci_fill_td(td, status, destination | uhci_explen(UHCI_NULL_DATA_SIZE) |
			(usb_gettoggle(urb->dev, usb_pipeendpoint(urb->pipe),
			 usb_pipeout(urb->pipe)) << TD_TOKEN_TOGGLE_SHIFT),
			data);

		usb_dotoggle(urb->dev, usb_pipeendpoint(urb->pipe),
			usb_pipeout(urb->pipe));
	}

	/* Set the interrupt-on-completion flag on the last packet.
	 * A more-or-less typical 4 KB URB (= size of one memory page)
	 * will require about 3 ms to transfer; that's a little on the
	 * fast side but not enough to justify delaying an interrupt
	 * more than 2 or 3 URBs, so we will ignore the URB_NO_INTERRUPT
	 * flag setting. */
	td->status |= cpu_to_le32(TD_CTRL_IOC);

	qh = uhci_alloc_qh(uhci, urb->dev);
	if (!qh)
		return -ENOMEM;

	urbp->qh = qh;
	qh->urbp = urbp;

	/* Always breadth first */
	uhci_insert_tds_in_qh(qh, urb, UHCI_PTR_BREADTH);

	if (eurb)
		uhci_append_queued_urb(uhci, eurb, urb);
	else
		uhci_insert_qh(uhci, skelqh, urb);

	return -EINPROGRESS;
}

/*
 * Common result for bulk and interrupt
 */
static int uhci_result_common(struct uhci_hcd *uhci, struct urb *urb)
{
	struct urb_priv *urbp = urb->hcpriv;
	struct uhci_td *td;
	unsigned int status = 0;
	int ret = 0;

	urb->actual_length = 0;

	list_for_each_entry(td, &urbp->td_list, list) {
		unsigned int ctrlstat = td_status(td);

		status = uhci_status_bits(ctrlstat);
		if (status & TD_CTRL_ACTIVE)
			return -EINPROGRESS;

		urb->actual_length += uhci_actual_length(ctrlstat);

		if (status)
			goto td_error;

		if (uhci_actual_length(ctrlstat) <
				uhci_expected_length(td_token(td))) {
			if (urb->transfer_flags & URB_SHORT_NOT_OK) {
				ret = -EREMOTEIO;
				goto err;
			} else
				return 0;
		}
	}

	return 0;

td_error:
	ret = uhci_map_status(status, uhci_packetout(td_token(td)));

err:
	/* 
	 * Enable this chunk of code if you want to see some more debugging.
	 * But be careful, it has the tendancy to starve out khubd and prevent
	 * disconnects from happening successfully if you have a slow debug
	 * log interface (like a serial console.
	 */
#if 0
	if ((debug == 1 && ret != -EPIPE) || debug > 1) {
		/* Some debugging code */
		dev_dbg(uhci_dev(uhci), "%s: failed with status %x\n",
				__FUNCTION__, status);

		if (errbuf) {
			/* Print the chain for debugging purposes */
			uhci_show_qh(urbp->qh, errbuf, ERRBUF_LEN, 0);

			lprintk(errbuf);
		}
	}
#endif
	return ret;
}

static inline int uhci_submit_bulk(struct uhci_hcd *uhci, struct urb *urb, struct urb *eurb)
{
	int ret;

	/* Can't have low-speed bulk transfers */
	if (urb->dev->speed == USB_SPEED_LOW)
		return -EINVAL;

	ret = uhci_submit_common(uhci, urb, eurb, uhci->skel_bulk_qh);
	if (ret == -EINPROGRESS)
		uhci_inc_fsbr(uhci, urb);

	return ret;
}

static inline int uhci_submit_interrupt(struct uhci_hcd *uhci, struct urb *urb, struct urb *eurb)
{
	/* USB 1.1 interrupt transfers only involve one packet per interval;
	 * that's the uhci_submit_common() "breadth first" policy.  Drivers
	 * can submit urbs of any length, but longer ones might need many
	 * intervals to complete.
	 */
	return uhci_submit_common(uhci, urb, eurb, uhci->skelqh[__interval_to_skel(urb->interval)]);
}

/*
 * Isochronous transfers
 */
static int isochronous_find_limits(struct uhci_hcd *uhci, struct urb *urb, unsigned int *start, unsigned int *end)
{
	struct urb *last_urb = NULL;
	struct urb_priv *up;
	int ret = 0;

	list_for_each_entry(up, &uhci->urb_list, urb_list) {
		struct urb *u = up->urb;

		/* look for pending URB's with identical pipe handle */
		if ((urb->pipe == u->pipe) && (urb->dev == u->dev) &&
		    (u->status == -EINPROGRESS) && (u != urb)) {
			if (!last_urb)
				*start = u->start_frame;
			last_urb = u;
		}
	}

	if (last_urb) {
		*end = (last_urb->start_frame + last_urb->number_of_packets *
				last_urb->interval) & (UHCI_NUMFRAMES-1);
		ret = 0;
	} else
		ret = -1;	/* no previous urb found */

	return ret;
}

static int isochronous_find_start(struct uhci_hcd *uhci, struct urb *urb)
{
	int limits;
	unsigned int start = 0, end = 0;

	if (urb->number_of_packets > 900)	/* 900? Why? */
		return -EFBIG;

	limits = isochronous_find_limits(uhci, urb, &start, &end);

	if (urb->transfer_flags & URB_ISO_ASAP) {
		if (limits)
			urb->start_frame =
					(uhci_get_current_frame_number(uhci) +
						10) & (UHCI_NUMFRAMES - 1);
		else
			urb->start_frame = end;
	} else {
		urb->start_frame &= (UHCI_NUMFRAMES - 1);
		/* FIXME: Sanity check */
	}

	return 0;
}

/*
 * Isochronous transfers
 */
static int uhci_submit_isochronous(struct uhci_hcd *uhci, struct urb *urb)
{
	struct uhci_td *td;
	int i, ret, frame;
	int status, destination;

	status = TD_CTRL_ACTIVE | TD_CTRL_IOS;
	destination = (urb->pipe & PIPE_DEVEP_MASK) | usb_packetid(urb->pipe);

	ret = isochronous_find_start(uhci, urb);
	if (ret)
		return ret;

	frame = urb->start_frame;
	for (i = 0; i < urb->number_of_packets; i++, frame += urb->interval) {
		if (!urb->iso_frame_desc[i].length)
			continue;

		td = uhci_alloc_td(uhci, urb->dev);
		if (!td)
			return -ENOMEM;

		uhci_add_td_to_urb(urb, td);
		uhci_fill_td(td, status, destination | uhci_explen(urb->iso_frame_desc[i].length - 1),
			urb->transfer_dma + urb->iso_frame_desc[i].offset);

		if (i + 1 >= urb->number_of_packets)
			td->status |= cpu_to_le32(TD_CTRL_IOC);

		uhci_insert_td_frame_list(uhci, td, frame);
	}

	return -EINPROGRESS;
}

static int uhci_result_isochronous(struct uhci_hcd *uhci, struct urb *urb)
{
	struct uhci_td *td;
	struct urb_priv *urbp = (struct urb_priv *)urb->hcpriv;
	int status;
	int i, ret = 0;

	urb->actual_length = 0;

	i = 0;
	list_for_each_entry(td, &urbp->td_list, list) {
		int actlength;
		unsigned int ctrlstat = td_status(td);

		if (ctrlstat & TD_CTRL_ACTIVE)
			return -EINPROGRESS;

		actlength = uhci_actual_length(ctrlstat);
		urb->iso_frame_desc[i].actual_length = actlength;
		urb->actual_length += actlength;

		status = uhci_map_status(uhci_status_bits(ctrlstat),
				usb_pipeout(urb->pipe));
		urb->iso_frame_desc[i].status = status;
		if (status) {
			urb->error_count++;
			ret = status;
		}

		i++;
	}

	return ret;
}

static struct urb *uhci_find_urb_ep(struct uhci_hcd *uhci, struct urb *urb)
{
	struct urb_priv *up;

	/* We don't match Isoc transfers since they are special */
	if (usb_pipeisoc(urb->pipe))
		return NULL;

	list_for_each_entry(up, &uhci->urb_list, urb_list) {
		struct urb *u = up->urb;

		if (u->dev == urb->dev && u->status == -EINPROGRESS) {
			/* For control, ignore the direction */
			if (usb_pipecontrol(urb->pipe) &&
			    (u->pipe & ~USB_DIR_IN) == (urb->pipe & ~USB_DIR_IN))
				return u;
			else if (u->pipe == urb->pipe)
				return u;
		}
	}

	return NULL;
}

static int uhci_urb_enqueue(struct usb_hcd *hcd,
		struct usb_host_endpoint *ep,
		struct urb *urb, int mem_flags)
{
	int ret;
	struct uhci_hcd *uhci = hcd_to_uhci(hcd);
	unsigned long flags;
	struct urb *eurb;
	int bustime;

	spin_lock_irqsave(&uhci->schedule_lock, flags);

	ret = urb->status;
	if (ret != -EINPROGRESS)		/* URB already unlinked! */
		goto out;

	eurb = uhci_find_urb_ep(uhci, urb);

	if (!uhci_alloc_urb_priv(uhci, urb)) {
		ret = -ENOMEM;
		goto out;
	}

	switch (usb_pipetype(urb->pipe)) {
	case PIPE_CONTROL:
		ret = uhci_submit_control(uhci, urb, eurb);
		break;
	case PIPE_INTERRUPT:
		if (!eurb) {
			bustime = usb_check_bandwidth(urb->dev, urb);
			if (bustime < 0)
				ret = bustime;
			else {
				ret = uhci_submit_interrupt(uhci, urb, eurb);
				if (ret == -EINPROGRESS)
					usb_claim_bandwidth(urb->dev, urb, bustime, 0);
			}
		} else {	/* inherit from parent */
			urb->bandwidth = eurb->bandwidth;
			ret = uhci_submit_interrupt(uhci, urb, eurb);
		}
		break;
	case PIPE_BULK:
		ret = uhci_submit_bulk(uhci, urb, eurb);
		break;
	case PIPE_ISOCHRONOUS:
		bustime = usb_check_bandwidth(urb->dev, urb);
		if (bustime < 0) {
			ret = bustime;
			break;
		}

		ret = uhci_submit_isochronous(uhci, urb);
		if (ret == -EINPROGRESS)
			usb_claim_bandwidth(urb->dev, urb, bustime, 1);
		break;
	}

	if (ret != -EINPROGRESS) {
		/* Submit failed, so delete it from the urb_list */
		struct urb_priv *urbp = urb->hcpriv;

		list_del_init(&urbp->urb_list);
		uhci_destroy_urb_priv(uhci, urb);
	} else
		ret = 0;

out:
	spin_unlock_irqrestore(&uhci->schedule_lock, flags);
	return ret;
}

/*
 * Return the result of a transfer
 */
static void uhci_transfer_result(struct uhci_hcd *uhci, struct urb *urb)
{
	int ret = -EINPROGRESS;
	struct urb_priv *urbp;

	spin_lock(&urb->lock);

	urbp = (struct urb_priv *)urb->hcpriv;

	if (urb->status != -EINPROGRESS)	/* URB already dequeued */
		goto out;

	switch (usb_pipetype(urb->pipe)) {
	case PIPE_CONTROL:
		ret = uhci_result_control(uhci, urb);
		break;
	case PIPE_BULK:
	case PIPE_INTERRUPT:
		ret = uhci_result_common(uhci, urb);
		break;
	case PIPE_ISOCHRONOUS:
		ret = uhci_result_isochronous(uhci, urb);
		break;
	}

	if (ret == -EINPROGRESS)
		goto out;
	urb->status = ret;

	switch (usb_pipetype(urb->pipe)) {
	case PIPE_CONTROL:
	case PIPE_BULK:
	case PIPE_ISOCHRONOUS:
		/* Release bandwidth for Interrupt or Isoc. transfers */
		if (urb->bandwidth)
			usb_release_bandwidth(urb->dev, urb, 1);
		uhci_unlink_generic(uhci, urb);
		break;
	case PIPE_INTERRUPT:
		/* Release bandwidth for Interrupt or Isoc. transfers */
		/* Make sure we don't release if we have a queued URB */
		if (list_empty(&urbp->queue_list) && urb->bandwidth)
			usb_release_bandwidth(urb->dev, urb, 0);
		else
			/* bandwidth was passed on to queued URB, */
			/* so don't let usb_unlink_urb() release it */
			urb->bandwidth = 0;
		uhci_unlink_generic(uhci, urb);
		break;
	default:
		dev_info(uhci_dev(uhci), "%s: unknown pipe type %d "
				"for urb %p\n",
				__FUNCTION__, usb_pipetype(urb->pipe), urb);
	}

	/* Move it from uhci->urb_list to uhci->complete_list */
	uhci_moveto_complete(uhci, urbp);

out:
	spin_unlock(&urb->lock);
}

static void uhci_unlink_generic(struct uhci_hcd *uhci, struct urb *urb)
{
	struct list_head *head;
	struct uhci_td *td;
	struct urb_priv *urbp = (struct urb_priv *)urb->hcpriv;
	int prevactive = 0;

	uhci_dec_fsbr(uhci, urb);	/* Safe since it checks */

	/*
	 * Now we need to find out what the last successful toggle was
	 * so we can update the local data toggle for the next transfer
	 *
	 * There are 2 ways the last successful completed TD is found:
	 *
	 * 1) The TD is NOT active and the actual length < expected length
	 * 2) The TD is NOT active and it's the last TD in the chain
	 *
	 * and a third way the first uncompleted TD is found:
	 *
	 * 3) The TD is active and the previous TD is NOT active
	 *
	 * Control and Isochronous ignore the toggle, so this is safe
	 * for all types
	 *
	 * FIXME: The toggle fixups won't be 100% reliable until we
	 * change over to using a single queue for each endpoint and
	 * stop the queue before unlinking.
	 */
	head = &urbp->td_list;
	list_for_each_entry(td, head, list) {
		unsigned int ctrlstat = td_status(td);

		if (!(ctrlstat & TD_CTRL_ACTIVE) &&
				(uhci_actual_length(ctrlstat) <
				 uhci_expected_length(td_token(td)) ||
				td->list.next == head))
			usb_settoggle(urb->dev, uhci_endpoint(td_token(td)),
				uhci_packetout(td_token(td)),
				uhci_toggle(td_token(td)) ^ 1);
		else if ((ctrlstat & TD_CTRL_ACTIVE) && !prevactive)
			usb_settoggle(urb->dev, uhci_endpoint(td_token(td)),
				uhci_packetout(td_token(td)),
				uhci_toggle(td_token(td)));

		prevactive = ctrlstat & TD_CTRL_ACTIVE;
	}