diff --git a/drivers/usb/host/uhci-debug.c b/drivers/usb/host/uhci-debug.c
index ecef5880cfd9936199719c0f72db7132d07826bc..ab8ba8220ad18a2bb12ba582935111b6fce9d3de 100644
--- a/drivers/usb/host/uhci-debug.c
+++ b/drivers/usb/host/uhci-debug.c
@@ -153,7 +153,7 @@ static int uhci_show_qh(struct uhci_qh *qh, char *buf, int len, int space)
 	char *qtype;
 
 	/* Try to make sure there's enough memory */
-	if (len < 80 * 6)
+	if (len < 80 * 7)
 		return 0;
 
 	switch (qh->type) {
@@ -167,6 +167,9 @@ static int uhci_show_qh(struct uhci_qh *qh, char *buf, int len, int space)
 	out += sprintf(out, "%*s[%p] %s QH link (%08x) element (%08x)\n",
 			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\n",
+				space, "", qh->period);
 
 	if (element & UHCI_PTR_QH)
 		out += sprintf(out, "%*s  Element points to QH (bug?)\n", space, "");
diff --git a/drivers/usb/host/uhci-hcd.h b/drivers/usb/host/uhci-hcd.h
index c87ceaa178b67470b3594b6061e975978358bdac..eaac6ddf03a07456ccec7acf57759102656fda0f 100644
--- a/drivers/usb/host/uhci-hcd.h
+++ b/drivers/usb/host/uhci-hcd.h
@@ -140,6 +140,8 @@ 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 */
+
 	int state;			/* QH_STATE_xxx; see above */
 	int type;			/* Queue type (control, bulk, etc) */
 
@@ -315,38 +317,8 @@ static inline u32 td_status(struct uhci_td *td) {
 #define skel_bulk_qh		skelqh[12]
 #define skel_term_qh		skelqh[13]
 
-/*
- * Search tree for determining where <interval> fits in the skelqh[]
- * skeleton.
- *
- * An interrupt request should be placed into the slowest skelqh[]
- * which meets the interval/period/frequency requirement.
- * An interrupt request is allowed to be faster than <interval> but not slower.
- *
- * For a given <interval>, this function returns the appropriate/matching
- * skelqh[] index value.
- */
-static inline int __interval_to_skel(int interval)
-{
-	if (interval < 16) {
-		if (interval < 4) {
-			if (interval < 2)
-				return 9;	/* int1 for 0-1 ms */
-			return 8;		/* int2 for 2-3 ms */
-		}
-		if (interval < 8)
-			return 7;		/* int4 for 4-7 ms */
-		return 6;			/* int8 for 8-15 ms */
-	}
-	if (interval < 64) {
-		if (interval < 32)
-			return 5;		/* int16 for 16-31 ms */
-		return 4;			/* int32 for 32-63 ms */
-	}
-	if (interval < 128)
-		return 3;			/* int64 for 64-127 ms */
-	return 2;				/* int128 for 128-255 ms (Max.) */
-}
+/* Find the skelqh entry corresponding to an interval exponent */
+#define UHCI_SKEL_INDEX(exponent)	(9 - exponent)
 
 
 /*
diff --git a/drivers/usb/host/uhci-q.c b/drivers/usb/host/uhci-q.c
index 96ce4c87c8719570351c17a1deca295c3e6d45a6..7acc23473c637f42c0fef4e693ea2169385b1beb 100644
--- a/drivers/usb/host/uhci-q.c
+++ b/drivers/usb/host/uhci-q.c
@@ -763,6 +763,7 @@ 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);
@@ -790,14 +791,30 @@ static inline int uhci_submit_bulk(struct uhci_hcd *uhci, struct urb *urb,
 	return ret;
 }
 
-static inline int uhci_submit_interrupt(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;
+
 	/* 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.
 	 */
-	qh->skel = uhci->skelqh[__interval_to_skel(urb->interval)];
+
+	/* Figure out which power-of-two queue to use */
+	for (exponent = 7; exponent >= 0; --exponent) {
+		if ((1 << exponent) <= urb->interval)
+			break;
+	}
+	if (exponent < 0)
+		return -EINVAL;
+	urb->interval = 1 << exponent;
+
+	if (qh->period == 0)
+		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);
 }
 
@@ -937,31 +954,50 @@ static int uhci_submit_isochronous(struct uhci_hcd *uhci, struct urb *urb,
 	unsigned long destination, status;
 	struct urb_priv *urbp = (struct urb_priv *) urb->hcpriv;
 
-	if (urb->number_of_packets > 900)	/* 900? Why? */
+	/* Values must not be too big (could overflow below) */
+	if (urb->interval >= UHCI_NUMFRAMES ||
+			urb->number_of_packets >= UHCI_NUMFRAMES)
 		return -EFBIG;
 
-	status = TD_CTRL_ACTIVE | TD_CTRL_IOS;
-	destination = (urb->pipe & PIPE_DEVEP_MASK) | usb_packetid(urb->pipe);
+	/* Check the period and figure out the starting frame number */
+	uhci_get_current_frame_number(uhci);
+	if (qh->period == 0) {
+		if (urb->transfer_flags & URB_ISO_ASAP) {
+			urb->start_frame = uhci->frame_number + 10;
+		} else {
+			i = urb->start_frame - uhci->frame_number;
+			if (i <= 0 || i >= UHCI_NUMFRAMES)
+				return -EINVAL;
+		}
+	} else if (qh->period != urb->interval) {
+		return -EINVAL;		/* Can't change the period */
 
-	/* Figure out the starting frame number */
-	if (urb->transfer_flags & URB_ISO_ASAP) {
+	} else {	/* Pick up where the last URB leaves off */
 		if (list_empty(&qh->queue)) {
-			uhci_get_current_frame_number(uhci);
-			urb->start_frame = (uhci->frame_number + 10);
-
-		} else {		/* Go right after the last one */
-			struct urb *last_urb;
+			frame = uhci->frame_number + 10;
+		} else {
+			struct urb *lurb;
 
-			last_urb = list_entry(qh->queue.prev,
+			lurb = list_entry(qh->queue.prev,
 					struct urb_priv, node)->urb;
-			urb->start_frame = (last_urb->start_frame +
-					last_urb->number_of_packets *
-					last_urb->interval);
+			frame = lurb->start_frame +
+					lurb->number_of_packets *
+					lurb->interval;
 		}
-	} else {
+		if (urb->transfer_flags & URB_ISO_ASAP)
+			urb->start_frame = frame;
 		/* FIXME: Sanity check */
 	}
 
+	/* Make sure we won't have to go too far into the future */
+	if (uhci_frame_before_eq(uhci->frame_number + UHCI_NUMFRAMES,
+			urb->start_frame + urb->number_of_packets *
+				urb->interval))
+		return -EFBIG;
+
+	status = TD_CTRL_ACTIVE | TD_CTRL_IOS;
+	destination = (urb->pipe & PIPE_DEVEP_MASK) | usb_packetid(urb->pipe);
+
 	for (i = 0; i < urb->number_of_packets; i++) {
 		td = uhci_alloc_td(uhci);
 		if (!td)
@@ -978,6 +1014,7 @@ static int uhci_submit_isochronous(struct uhci_hcd *uhci, struct urb *urb,
 	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;
@@ -1206,6 +1243,7 @@ __acquires(uhci->lock)
 		uhci_unlink_qh(uhci, qh);
 
 		/* Bandwidth stuff not yet implemented */
+		qh->period = 0;
 	}
 }