drivers/usb/host/ohci-hcd.c |   65 ++++++++++++++++++++++++++++++++++++++++++++
 drivers/usb/host/ohci-q.c   |   10 ++++++
 2 files changed, 74 insertions(+), 1 deletion(-)

Index: usb-3.10/drivers/usb/host/ohci-hcd.c
===================================================================
--- usb-3.10.orig/drivers/usb/host/ohci-hcd.c
+++ usb-3.10/drivers/usb/host/ohci-hcd.c
@@ -81,6 +81,66 @@ static const char	hcd_name [] = "ohci_hc
 static void ohci_dump (struct ohci_hcd *ohci, int verbose);
 static void ohci_stop (struct usb_hcd *hcd);
 
+#include <linux/hrtimer.h>
+
+static struct ohci_hcd	*alan_ohci;
+static struct ed	*alan_ed;
+static struct hrtimer	alan_hrtimer;
+static int		alan_irq_cnt, alan_wdh_cnt, alan_iso_cnt;
+
+static enum hrtimer_restart alan_hrtimer_func(struct hrtimer *t)
+{
+	ktime_t		timeout;
+	struct ed	*ed;
+	struct td	*td;
+	u16		cf, sf, tdPSW;
+
+	ed = ACCESS_ONCE(alan_ed);
+	if (!ed)
+		return HRTIMER_NORESTART;
+
+	if (alan_irq_cnt == 0 || alan_wdh_cnt == 0 || alan_iso_cnt == 0) {
+		ohci_info(alan_ohci, "Alan debug: irq %d wdh %d iso %d\n",
+				alan_irq_cnt, alan_wdh_cnt, alan_iso_cnt);
+		if (!list_empty(&ed->td_list)) {
+			cf = ohci_frame_no(alan_ohci);
+			td = list_entry(ed->td_list.next, struct td,
+					td_list);
+			sf = hc32_to_cpu(alan_ohci, td->hwINFO);
+			tdPSW = ohci_hwPSW(alan_ohci, td, 0);
+			ohci_info(alan_ohci, " td %p cf %04x sf %04x cc %x\n",
+					td, cf, sf, tdPSW >> 12);
+		}
+	}
+
+	alan_irq_cnt = alan_wdh_cnt = alan_iso_cnt = 0;
+	timeout = ktime_add(ktime_get(),
+			ktime_set(0, 2 * NSEC_PER_MSEC));
+	hrtimer_start_range_ns(&alan_hrtimer, timeout,
+			NSEC_PER_MSEC, HRTIMER_MODE_ABS);
+	return HRTIMER_NORESTART;
+}
+
+static void alan_start(struct ohci_hcd *ohci, struct ed *ed, struct urb *urb)
+{
+	if (urb->interval == 1 && urb->number_of_packets == 1) {
+		alan_ohci = ohci;
+		alan_ed = ed;
+		alan_irq_cnt = alan_wdh_cnt = alan_iso_cnt = 1;
+		hrtimer_init(&alan_hrtimer, CLOCK_MONOTONIC, HRTIMER_MODE_ABS);
+		alan_hrtimer.function = alan_hrtimer_func;
+		alan_hrtimer_func(&alan_hrtimer);
+	}
+}
+
+static void alan_stop(struct ohci_hcd *ohci)
+{
+	if (ohci == alan_ohci) {
+		alan_ed = NULL;
+		hrtimer_try_to_cancel(&alan_hrtimer);
+	}
+}
+
 #include "ohci-hub.c"
 #include "ohci-dbg.c"
 #include "ohci-mem.c"
@@ -816,6 +876,9 @@ static irqreturn_t ohci_irq (struct usb_
 	if (ints == 0 || unlikely(ohci->rh_state == OHCI_RH_HALTED))
 		return IRQ_NOTMINE;
 
+	if (ohci == alan_ohci)
+		++alan_irq_cnt;
+
 	if (ints & OHCI_INTR_UE) {
 		// e.g. due to PCI Master/Target Abort
 		if (quirk_nec(ohci)) {
@@ -872,6 +935,8 @@ static irqreturn_t ohci_irq (struct usb_
 	}
 
 	if (ints & OHCI_INTR_WDH) {
+		if (ohci == alan_ohci)
+			++alan_wdh_cnt;
 		spin_lock (&ohci->lock);
 		dl_done_list (ohci);
 		spin_unlock (&ohci->lock);
Index: usb-3.10/drivers/usb/host/ohci-q.c
===================================================================
--- usb-3.10.orig/drivers/usb/host/ohci-q.c
+++ usb-3.10/drivers/usb/host/ohci-q.c
@@ -1081,16 +1081,24 @@ static void takeback_td(struct ohci_hcd
 	struct ed	*ed = td->ed;
 	int		status;
 
+	if (ed->type == PIPE_ISOCHRONOUS && !alan_ed)
+		alan_start(ohci, ed, urb);
+
 	/* update URB's length and status from TD */
 	status = td_done(ohci, urb, td);
 	urb_priv->td_cnt++;
 
 	/* If all this urb's TDs are done, call complete() */
-	if (urb_priv->td_cnt == urb_priv->length)
+	if (urb_priv->td_cnt == urb_priv->length) {
+		if (ed == alan_ed)
+			++alan_iso_cnt;
 		finish_urb(ohci, urb, status);
+	}
 
 	/* clean schedule:  unlink EDs that are no longer busy */
 	if (list_empty(&ed->td_list)) {
+		if (ed == alan_ed)
+			alan_stop(ohci);
 		if (ed->state == ED_OPER)
 			start_ed_unlink(ohci, ed);