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Commit 3ca2a321 authored by Alan Stern's avatar Alan Stern Committed by Greg Kroah-Hartman
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UHCI: fix bandwidth allocation 



This patch (as840) fixes the bandwidth allocation mechanism in
uhci-hcd.  It has never worked correctly.

Signed-off-by: default avatarAlan Stern <stern@rowland.harvard.edu>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@suse.de>
parent 6a6c957e

drivers/usb/host/uhci-debug.c

+18 −3
Original line number Diff line number Diff line
@@ -168,9 +168,13 @@ static int uhci_show_qh(struct uhci_qh *qh, char *buf, int len, int space) 
			space, "", qh, qtype,

			le32_to_cpu(qh->link), le32_to_cpu(element));

	if (qh->type == USB_ENDPOINT_XFER_ISOC)

		out += sprintf(out, "%*s    period %d frame %x desc [%p]\n",

				space, "", qh->period, qh->iso_frame,

				qh->iso_packet_desc);

		out += sprintf(out, "%*s    period %d phase %d load %d us, "

				"frame %x desc [%p]\n",

				space, "", qh->period, qh->phase, qh->load,

				qh->iso_frame, qh->iso_packet_desc);

	else if (qh->type == USB_ENDPOINT_XFER_INT)

		out += sprintf(out, "%*s    period %d phase %d load %d us\n",

				space, "", qh->period, qh->phase, qh->load);



	if (element & UHCI_PTR_QH)

		out += sprintf(out, "%*s  Element points to QH (bug?)\n", space, "");
@@ -352,6 +356,17 @@ static int uhci_sprint_schedule(struct uhci_hcd *uhci, char *buf, int len) 
	out += uhci_show_root_hub_state(uhci, out, len - (out - buf));

	out += sprintf(out, "HC status\n");

	out += uhci_show_status(uhci, out, len - (out - buf));



	out += sprintf(out, "Periodic load table\n");

	for (i = 0; i < MAX_PHASE; ++i) {

		out += sprintf(out, "\t%d", uhci->load[i]);

		if (i % 8 == 7)

			*out++ = '\n';

	}

	out += sprintf(out, "Total: %d, #INT: %d, #ISO: %d\n",

			uhci->total_load,

			uhci_to_hcd(uhci)->self.bandwidth_int_reqs,

			uhci_to_hcd(uhci)->self.bandwidth_isoc_reqs);

	if (debug <= 1)

		return out - buf;

drivers/usb/host/uhci-hcd.h

+8 −0
Original line number Diff line number Diff line
@@ -83,6 +83,7 @@ 
#define UHCI_MAX_SOF_NUMBER	2047	/* in an SOF packet */

#define CAN_SCHEDULE_FRAMES	1000	/* how far in the future frames

					 * can be scheduled */

#define MAX_PHASE		32	/* Periodic scheduling length */



/* When no queues need Full-Speed Bandwidth Reclamation,

 * delay this long before turning FSBR off */
@@ -141,6 +142,8 @@ struct uhci_qh { 
	unsigned long advance_jiffies;	/* Time of last queue advance */

	unsigned int unlink_frame;	/* When the QH was unlinked */

	unsigned int period;		/* For Interrupt and Isochronous QHs */

	short phase;			/* Between 0 and period-1 */

	short load;			/* Periodic time requirement, in us */

	unsigned int iso_frame;		/* Frame # for iso_packet_desc */

	int iso_status;			/* Status for Isochronous URBs */
@@ -153,6 +156,8 @@ struct uhci_qh { 
	unsigned int needs_fixup:1;	/* Must fix the TD toggle values */

	unsigned int is_stopped:1;	/* Queue was stopped by error/unlink */

	unsigned int wait_expired:1;	/* QH_WAIT_TIMEOUT has expired */

	unsigned int bandwidth_reserved:1;	/* Periodic bandwidth has

						 * been allocated */

} __attribute__((aligned(16)));



/*
@@ -414,6 +419,9 @@ struct uhci_hcd { 


	wait_queue_head_t waitqh;		/* endpoint_disable waiters */

	int num_waiting;			/* Number of waiters */



	int total_load;				/* Sum of array values */

	short load[MAX_PHASE];			/* Periodic allocations */

};



/* Convert between a usb_hcd pointer and the corresponding uhci_hcd */

drivers/usb/host/uhci-q.c

+175 −66
Original line number Diff line number Diff line
@@ -261,6 +261,14 @@ static struct uhci_qh *uhci_alloc_qh(struct uhci_hcd *uhci, 
		qh->udev = udev;

		hep->hcpriv = qh;



		if (qh->type == USB_ENDPOINT_XFER_INT ||

				qh->type == USB_ENDPOINT_XFER_ISOC)

			qh->load = usb_calc_bus_time(udev->speed,

					usb_endpoint_dir_in(&hep->desc),

					qh->type == USB_ENDPOINT_XFER_ISOC,

					le16_to_cpu(hep->desc.wMaxPacketSize))

				/ 1000 + 1;



	} else {		/* Skeleton QH */

		qh->state = QH_STATE_ACTIVE;

		qh->type = -1;
@@ -496,6 +504,121 @@ static void uhci_make_qh_idle(struct uhci_hcd *uhci, struct uhci_qh *qh) 
		wake_up_all(&uhci->waitqh);

}



/*

 * Find the highest existing bandwidth load for a given phase and period.

 */

static int uhci_highest_load(struct uhci_hcd *uhci, int phase, int period)

{

	int highest_load = uhci->load[phase];



	for (phase += period; phase < MAX_PHASE; phase += period)

		highest_load = max_t(int, highest_load, uhci->load[phase]);

	return highest_load;

}



/*

 * Set qh->phase to the optimal phase for a periodic transfer and

 * check whether the bandwidth requirement is acceptable.

 */

static int uhci_check_bandwidth(struct uhci_hcd *uhci, struct uhci_qh *qh)

{

	int minimax_load;



	/* Find the optimal phase (unless it is already set) and get

	 * its load value. */

	if (qh->phase >= 0)

		minimax_load = uhci_highest_load(uhci, qh->phase, qh->period);

	else {

		int phase, load;

		int max_phase = min_t(int, MAX_PHASE, qh->period);



		qh->phase = 0;

		minimax_load = uhci_highest_load(uhci, qh->phase, qh->period);

		for (phase = 1; phase < max_phase; ++phase) {

			load = uhci_highest_load(uhci, phase, qh->period);

			if (load < minimax_load) {

				minimax_load = load;

				qh->phase = phase;

			}

		}

	}



	/* Maximum allowable periodic bandwidth is 90%, or 900 us per frame */

	if (minimax_load + qh->load > 900) {

		dev_dbg(uhci_dev(uhci), "bandwidth allocation failed: "

				"period %d, phase %d, %d + %d us\n",

				qh->period, qh->phase, minimax_load, qh->load);

		return -ENOSPC;

	}

	return 0;

}



/*

 * Reserve a periodic QH's bandwidth in the schedule

 */

static void uhci_reserve_bandwidth(struct uhci_hcd *uhci, struct uhci_qh *qh)

{

	int i;

	int load = qh->load;

	char *p = "??";



	for (i = qh->phase; i < MAX_PHASE; i += qh->period) {

		uhci->load[i] += load;

		uhci->total_load += load;

	}

	uhci_to_hcd(uhci)->self.bandwidth_allocated =

			uhci->total_load / MAX_PHASE;

	switch (qh->type) {

	case USB_ENDPOINT_XFER_INT:

		++uhci_to_hcd(uhci)->self.bandwidth_int_reqs;

		p = "INT";

		break;

	case USB_ENDPOINT_XFER_ISOC:

		++uhci_to_hcd(uhci)->self.bandwidth_isoc_reqs;

		p = "ISO";

		break;

	}

	qh->bandwidth_reserved = 1;

	dev_dbg(uhci_dev(uhci),

			"%s dev %d ep%02x-%s, period %d, phase %d, %d us\n",

			"reserve", qh->udev->devnum,

			qh->hep->desc.bEndpointAddress, p,

			qh->period, qh->phase, load);

}



/*

 * Release a periodic QH's bandwidth reservation

 */

static void uhci_release_bandwidth(struct uhci_hcd *uhci, struct uhci_qh *qh)

{

	int i;

	int load = qh->load;

	char *p = "??";



	for (i = qh->phase; i < MAX_PHASE; i += qh->period) {

		uhci->load[i] -= load;

		uhci->total_load -= load;

	}

	uhci_to_hcd(uhci)->self.bandwidth_allocated =

			uhci->total_load / MAX_PHASE;

	switch (qh->type) {

	case USB_ENDPOINT_XFER_INT:

		--uhci_to_hcd(uhci)->self.bandwidth_int_reqs;

		p = "INT";

		break;

	case USB_ENDPOINT_XFER_ISOC:

		--uhci_to_hcd(uhci)->self.bandwidth_isoc_reqs;

		p = "ISO";

		break;

	}

	qh->bandwidth_reserved = 0;

	dev_dbg(uhci_dev(uhci),

			"%s dev %d ep%02x-%s, period %d, phase %d, %d us\n",

			"release", qh->udev->devnum,

			qh->hep->desc.bEndpointAddress, p,

			qh->period, qh->phase, load);

}



static inline struct urb_priv *uhci_alloc_urb_priv(struct uhci_hcd *uhci,

		struct urb *urb)

{
@@ -799,7 +922,6 @@ static int uhci_submit_common(struct uhci_hcd *uhci, struct urb *urb, 
	wmb();

	qh->dummy_td->status |= __constant_cpu_to_le32(TD_CTRL_ACTIVE);

	qh->dummy_td = td;

	qh->period = urb->interval;



	usb_settoggle(urb->dev, usb_pipeendpoint(urb->pipe),

			usb_pipeout(urb->pipe), toggle);
@@ -830,13 +952,16 @@ static inline int uhci_submit_bulk(struct uhci_hcd *uhci, struct urb *urb, 
static int uhci_submit_interrupt(struct uhci_hcd *uhci, struct urb *urb,

		struct uhci_qh *qh)

{

	int exponent;

	int ret;



	/* USB 1.1 interrupt transfers only involve one packet per interval.

	 * Drivers can submit URBs of any length, but longer ones will need

	 * multiple intervals to complete.

	 */



	if (!qh->bandwidth_reserved) {

		int exponent;



		/* Figure out which power-of-two queue to use */

		for (exponent = 7; exponent >= 0; --exponent) {

			if ((1 << exponent) <= urb->interval)
@@ -844,14 +969,25 @@ static int uhci_submit_interrupt(struct uhci_hcd *uhci, struct urb *urb, 
		}

		if (exponent < 0)

			return -EINVAL;

	urb->interval = 1 << exponent;



	if (qh->period == 0)

		qh->period = 1 << exponent;

		qh->skel = uhci->skelqh[UHCI_SKEL_INDEX(exponent)];

	else if (qh->period != urb->interval)

		return -EINVAL;		/* Can't change the period */



	return uhci_submit_common(uhci, urb, qh);

		/* For now, interrupt phase is fixed by the layout

		 * of the QH lists. */

		qh->phase = (qh->period / 2) & (MAX_PHASE - 1);

		ret = uhci_check_bandwidth(uhci, qh);

		if (ret)

			return ret;

	} else if (qh->period > urb->interval)

		return -EINVAL;		/* Can't decrease the period */



	ret = uhci_submit_common(uhci, urb, qh);

	if (ret == 0) {

		urb->interval = qh->period;

		if (!qh->bandwidth_reserved)

			uhci_reserve_bandwidth(uhci, qh);

	}

	return ret;

}



/*
@@ -998,15 +1134,32 @@ static int uhci_submit_isochronous(struct uhci_hcd *uhci, struct urb *urb, 
		return -EFBIG;



	/* Check the period and figure out the starting frame number */

	if (qh->period == 0) {

	if (!qh->bandwidth_reserved) {

		qh->period = urb->interval;

		if (urb->transfer_flags & URB_ISO_ASAP) {

			qh->phase = -1;		/* Find the best phase */

			i = uhci_check_bandwidth(uhci, qh);

			if (i)

				return i;



			/* Allow a little time to allocate the TDs */

			uhci_get_current_frame_number(uhci);

			urb->start_frame = uhci->frame_number + 10;

			frame = uhci->frame_number + 10;



			/* Move forward to the first frame having the

			 * correct phase */

			urb->start_frame = frame + ((qh->phase - frame) &

					(qh->period - 1));

		} else {

			i = urb->start_frame - uhci->last_iso_frame;

			if (i <= 0 || i >= UHCI_NUMFRAMES)

				return -EINVAL;

			qh->phase = urb->start_frame & (qh->period - 1);

			i = uhci_check_bandwidth(uhci, qh);

			if (i)

				return i;

		}



	} else if (qh->period != urb->interval) {

		return -EINVAL;		/* Can't change the period */
@@ -1052,9 +1205,6 @@ static int uhci_submit_isochronous(struct uhci_hcd *uhci, struct urb *urb, 
	/* Set the interrupt-on-completion flag on the last packet. */

	td->status |= __constant_cpu_to_le32(TD_CTRL_IOC);



	qh->skel = uhci->skel_iso_qh;

	qh->period = urb->interval;



	/* Add the TDs to the frame list */

	frame = urb->start_frame;

	list_for_each_entry(td, &urbp->td_list, list) {
@@ -1068,6 +1218,9 @@ static int uhci_submit_isochronous(struct uhci_hcd *uhci, struct urb *urb, 
		qh->iso_status = 0;

	}



	qh->skel = uhci->skel_iso_qh;

	if (!qh->bandwidth_reserved)

		uhci_reserve_bandwidth(uhci, qh);

	return 0;

}
@@ -1122,7 +1275,6 @@ static int uhci_urb_enqueue(struct usb_hcd *hcd, 
	unsigned long flags;

	struct urb_priv *urbp;

	struct uhci_qh *qh;

	int bustime;



	spin_lock_irqsave(&uhci->lock, flags);
@@ -1152,35 +1304,11 @@ static int uhci_urb_enqueue(struct usb_hcd *hcd, 
		ret = uhci_submit_bulk(uhci, urb, qh);

		break;

	case USB_ENDPOINT_XFER_INT:

		if (list_empty(&qh->queue)) {

			bustime = usb_check_bandwidth(urb->dev, urb);

			if (bustime < 0)

				ret = bustime;

			else {

		ret = uhci_submit_interrupt(uhci, urb, qh);

				if (ret == 0)

					usb_claim_bandwidth(urb->dev, urb, bustime, 0);

			}

		} else {	/* inherit from parent */

			struct urb_priv *eurbp;



			eurbp = list_entry(qh->queue.prev, struct urb_priv,

					node);

			urb->bandwidth = eurbp->urb->bandwidth;

			ret = uhci_submit_interrupt(uhci, urb, qh);

		}

		break;

	case USB_ENDPOINT_XFER_ISOC:

		urb->error_count = 0;

		bustime = usb_check_bandwidth(urb->dev, urb);

		if (bustime < 0) {

			ret = bustime;

			break;

		}



		ret = uhci_submit_isochronous(uhci, urb, qh);

		if (ret == 0)

			usb_claim_bandwidth(urb->dev, urb, bustime, 1);

		break;

	}

	if (ret != 0)
@@ -1277,24 +1405,6 @@ __acquires(uhci->lock) 


	uhci_free_urb_priv(uhci, urbp);



	switch (qh->type) {

	case USB_ENDPOINT_XFER_ISOC:

		/* Release bandwidth for Interrupt or Isoc. transfers */

		if (urb->bandwidth)

			usb_release_bandwidth(urb->dev, urb, 1);

		break;

	case USB_ENDPOINT_XFER_INT:

		/* Release bandwidth for Interrupt or Isoc. transfers */

		/* Make sure we don't release if we have a queued URB */

		if (list_empty(&qh->queue) && 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;

		break;

	}



	spin_unlock(&uhci->lock);

	usb_hcd_giveback_urb(uhci_to_hcd(uhci), urb);

	spin_lock(&uhci->lock);
@@ -1303,9 +1413,8 @@ __acquires(uhci->lock) 
	 * reserved bandwidth. */

	if (list_empty(&qh->queue)) {

		uhci_unlink_qh(uhci, qh);



		/* Bandwidth stuff not yet implemented */

		qh->period = 0;

		if (qh->bandwidth_reserved)

			uhci_release_bandwidth(uhci, qh);

	}

}