diff --git a/drivers/usb/class/cdc-acm.c b/drivers/usb/class/cdc-acm.c
index e3861b21e776600fb721699c8ede4e62dc51f8fc..e4eca7810bcf1bed6821086e4bab6130525e3c17 100644
--- a/drivers/usb/class/cdc-acm.c
+++ b/drivers/usb/class/cdc-acm.c
@@ -609,9 +609,9 @@ static int acm_tty_open(struct tty_struct *tty, struct file *filp)
 
 	acm->throttle = 0;
 
-	tasklet_schedule(&acm->urb_task);
 	set_bit(ASYNCB_INITIALIZED, &acm->port.flags);
 	rv = tty_port_block_til_ready(&acm->port, tty, filp);
+	tasklet_schedule(&acm->urb_task);
 done:
 	mutex_unlock(&acm->mutex);
 err_out:
@@ -686,15 +686,21 @@ static void acm_tty_close(struct tty_struct *tty, struct file *filp)
 
 	/* Perform the closing process and see if we need to do the hardware
 	   shutdown */
-	if (!acm || tty_port_close_start(&acm->port, tty, filp) == 0)
+	if (!acm)
+		return;
+	if (tty_port_close_start(&acm->port, tty, filp) == 0) {
+		mutex_lock(&open_mutex);
+		if (!acm->dev) {
+			tty_port_tty_set(&acm->port, NULL);
+			acm_tty_unregister(acm);
+			tty->driver_data = NULL;
+		}
+		mutex_unlock(&open_mutex);
 		return;
+	}
 	acm_port_down(acm, 0);
 	tty_port_close_end(&acm->port, tty);
-	mutex_lock(&open_mutex);
 	tty_port_tty_set(&acm->port, NULL);
-	if (!acm->dev)
-		acm_tty_unregister(acm);
-	mutex_unlock(&open_mutex);
 }
 
 static int acm_tty_write(struct tty_struct *tty,
diff --git a/drivers/usb/host/ohci-hcd.c b/drivers/usb/host/ohci-hcd.c
index 78bb7710f36d9ef641f7857b3f688b5c2c9640af..24eb74781919d58ed4454a4e7c1dd7999e04ade1 100644
--- a/drivers/usb/host/ohci-hcd.c
+++ b/drivers/usb/host/ohci-hcd.c
@@ -87,6 +87,7 @@ static int ohci_restart (struct ohci_hcd *ohci);
 #ifdef CONFIG_PCI
 static void quirk_amd_pll(int state);
 static void amd_iso_dev_put(void);
+static void sb800_prefetch(struct ohci_hcd *ohci, int on);
 #else
 static inline void quirk_amd_pll(int state)
 {
@@ -96,6 +97,10 @@ static inline void amd_iso_dev_put(void)
 {
 	return;
 }
+static inline void sb800_prefetch(struct ohci_hcd *ohci, int on)
+{
+	return;
+}
 #endif
 
 
diff --git a/drivers/usb/host/ohci-pci.c b/drivers/usb/host/ohci-pci.c
index d2ba04dd785e4942d69ad28f4b2a3a727d3efd54..b8a1148f248e4faeb404fbcedf76e6c36d0e6ea2 100644
--- a/drivers/usb/host/ohci-pci.c
+++ b/drivers/usb/host/ohci-pci.c
@@ -177,6 +177,13 @@ static int ohci_quirk_amd700(struct usb_hcd *hcd)
 		return 0;
 
 	pci_read_config_byte(amd_smbus_dev, PCI_REVISION_ID, &rev);
+
+	/* SB800 needs pre-fetch fix */
+	if ((rev >= 0x40) && (rev <= 0x4f)) {
+		ohci->flags |= OHCI_QUIRK_AMD_PREFETCH;
+		ohci_dbg(ohci, "enabled AMD prefetch quirk\n");
+	}
+
 	if ((rev > 0x3b) || (rev < 0x30)) {
 		pci_dev_put(amd_smbus_dev);
 		amd_smbus_dev = NULL;
@@ -262,6 +269,19 @@ static void amd_iso_dev_put(void)
 
 }
 
+static void sb800_prefetch(struct ohci_hcd *ohci, int on)
+{
+	struct pci_dev *pdev;
+	u16 misc;
+
+	pdev = to_pci_dev(ohci_to_hcd(ohci)->self.controller);
+	pci_read_config_word(pdev, 0x50, &misc);
+	if (on == 0)
+		pci_write_config_word(pdev, 0x50, misc & 0xfcff);
+	else
+		pci_write_config_word(pdev, 0x50, misc | 0x0300);
+}
+
 /* List of quirks for OHCI */
 static const struct pci_device_id ohci_pci_quirks[] = {
 	{
diff --git a/drivers/usb/host/ohci-q.c b/drivers/usb/host/ohci-q.c
index 16fecb8ecc39dde0360153ac4f1637c036fd0ab5..35288bcae0dbc10ccc04fe380e36ba8026f1220a 100644
--- a/drivers/usb/host/ohci-q.c
+++ b/drivers/usb/host/ohci-q.c
@@ -49,9 +49,12 @@ __acquires(ohci->lock)
 	switch (usb_pipetype (urb->pipe)) {
 	case PIPE_ISOCHRONOUS:
 		ohci_to_hcd(ohci)->self.bandwidth_isoc_reqs--;
-		if (ohci_to_hcd(ohci)->self.bandwidth_isoc_reqs == 0
-				&& quirk_amdiso(ohci))
-			quirk_amd_pll(1);
+		if (ohci_to_hcd(ohci)->self.bandwidth_isoc_reqs == 0) {
+			if (quirk_amdiso(ohci))
+				quirk_amd_pll(1);
+			if (quirk_amdprefetch(ohci))
+				sb800_prefetch(ohci, 0);
+		}
 		break;
 	case PIPE_INTERRUPT:
 		ohci_to_hcd(ohci)->self.bandwidth_int_reqs--;
@@ -680,9 +683,12 @@ static void td_submit_urb (
 				data + urb->iso_frame_desc [cnt].offset,
 				urb->iso_frame_desc [cnt].length, urb, cnt);
 		}
-		if (ohci_to_hcd(ohci)->self.bandwidth_isoc_reqs == 0
-				&& quirk_amdiso(ohci))
-			quirk_amd_pll(0);
+		if (ohci_to_hcd(ohci)->self.bandwidth_isoc_reqs == 0) {
+			if (quirk_amdiso(ohci))
+				quirk_amd_pll(0);
+			if (quirk_amdprefetch(ohci))
+				sb800_prefetch(ohci, 1);
+		}
 		periodic = ohci_to_hcd(ohci)->self.bandwidth_isoc_reqs++ == 0
 			&& ohci_to_hcd(ohci)->self.bandwidth_int_reqs == 0;
 		break;
diff --git a/drivers/usb/host/ohci.h b/drivers/usb/host/ohci.h
index 222011f6172cbccd23b199e85319730f72f7bb52..5bf15fed0d9fcd4f4654bb51c7ae38ea82cf905c 100644
--- a/drivers/usb/host/ohci.h
+++ b/drivers/usb/host/ohci.h
@@ -402,6 +402,7 @@ struct ohci_hcd {
 #define	OHCI_QUIRK_FRAME_NO	0x80			/* no big endian frame_no shift */
 #define	OHCI_QUIRK_HUB_POWER	0x100			/* distrust firmware power/oc setup */
 #define	OHCI_QUIRK_AMD_ISO	0x200			/* ISO transfers*/
+#define	OHCI_QUIRK_AMD_PREFETCH	0x400			/* pre-fetch for ISO transfer */
 	// there are also chip quirks/bugs in init logic
 
 	struct work_struct	nec_work;	/* Worker for NEC quirk */
@@ -433,6 +434,10 @@ static inline int quirk_amdiso(struct ohci_hcd *ohci)
 {
 	return ohci->flags & OHCI_QUIRK_AMD_ISO;
 }
+static inline int quirk_amdprefetch(struct ohci_hcd *ohci)
+{
+	return ohci->flags & OHCI_QUIRK_AMD_PREFETCH;
+}
 #else
 static inline int quirk_nec(struct ohci_hcd *ohci)
 {
@@ -446,6 +451,10 @@ static inline int quirk_amdiso(struct ohci_hcd *ohci)
 {
 	return 0;
 }
+static inline int quirk_amdprefetch(struct ohci_hcd *ohci)
+{
+	return 0;
+}
 #endif
 
 /* convert between an hcd pointer and the corresponding ohci_hcd */
diff --git a/drivers/usb/host/xhci-mem.c b/drivers/usb/host/xhci-mem.c
index 1db4fea8c1704e62cdc33ddfeacc353f70273a09..b8fd270a8b0d5f2630ed87dbcf6d24f8a566c86e 100644
--- a/drivers/usb/host/xhci-mem.c
+++ b/drivers/usb/host/xhci-mem.c
@@ -802,9 +802,11 @@ void xhci_mem_cleanup(struct xhci_hcd *xhci)
 	int i;
 
 	/* Free the Event Ring Segment Table and the actual Event Ring */
-	xhci_writel(xhci, 0, &xhci->ir_set->erst_size);
-	xhci_write_64(xhci, 0, &xhci->ir_set->erst_base);
-	xhci_write_64(xhci, 0, &xhci->ir_set->erst_dequeue);
+	if (xhci->ir_set) {
+		xhci_writel(xhci, 0, &xhci->ir_set->erst_size);
+		xhci_write_64(xhci, 0, &xhci->ir_set->erst_base);
+		xhci_write_64(xhci, 0, &xhci->ir_set->erst_dequeue);
+	}
 	size = sizeof(struct xhci_erst_entry)*(xhci->erst.num_entries);
 	if (xhci->erst.entries)
 		pci_free_consistent(pdev, size,
@@ -841,9 +843,9 @@ void xhci_mem_cleanup(struct xhci_hcd *xhci)
 				xhci->dcbaa, xhci->dcbaa->dma);
 	xhci->dcbaa = NULL;
 
+	scratchpad_free(xhci);
 	xhci->page_size = 0;
 	xhci->page_shift = 0;
-	scratchpad_free(xhci);
 }
 
 int xhci_mem_init(struct xhci_hcd *xhci, gfp_t flags)
diff --git a/drivers/usb/host/xhci-ring.c b/drivers/usb/host/xhci-ring.c
index 173c39c7648912a1e63ef53a38881c4091094a07..821b7b4709de6531b28afb78c428ad4f5379ff81 100644
--- a/drivers/usb/host/xhci-ring.c
+++ b/drivers/usb/host/xhci-ring.c
@@ -864,9 +864,11 @@ static struct xhci_segment *trb_in_td(
 	cur_seg = start_seg;
 
 	do {
+		if (start_dma == 0)
+			return 0;
 		/* We may get an event for a Link TRB in the middle of a TD */
 		end_seg_dma = xhci_trb_virt_to_dma(cur_seg,
-				&start_seg->trbs[TRBS_PER_SEGMENT - 1]);
+				&cur_seg->trbs[TRBS_PER_SEGMENT - 1]);
 		/* If the end TRB isn't in this segment, this is set to 0 */
 		end_trb_dma = xhci_trb_virt_to_dma(cur_seg, end_trb);
 
@@ -893,8 +895,9 @@ static struct xhci_segment *trb_in_td(
 		}
 		cur_seg = cur_seg->next;
 		start_dma = xhci_trb_virt_to_dma(cur_seg, &cur_seg->trbs[0]);
-	} while (1);
+	} while (cur_seg != start_seg);
 
+	return 0;
 }
 
 /*
diff --git a/drivers/usb/mon/mon_bin.c b/drivers/usb/mon/mon_bin.c
index 9ed3e741bee160c7f2d71906810146f95f1da59a..10f3205798e880ce4f1351735666bac903e34398 100644
--- a/drivers/usb/mon/mon_bin.c
+++ b/drivers/usb/mon/mon_bin.c
@@ -348,12 +348,12 @@ static unsigned int mon_buff_area_alloc_contiguous(struct mon_reader_bin *rp,
 
 /*
  * Return a few (kilo-)bytes to the head of the buffer.
- * This is used if a DMA fetch fails.
+ * This is used if a data fetch fails.
  */
 static void mon_buff_area_shrink(struct mon_reader_bin *rp, unsigned int size)
 {
 
-	size = (size + PKT_ALIGN-1) & ~(PKT_ALIGN-1);
+	/* size &= ~(PKT_ALIGN-1);  -- we're called with aligned size */
 	rp->b_cnt -= size;
 	if (rp->b_in < size)
 		rp->b_in += rp->b_size;
@@ -433,6 +433,7 @@ static void mon_bin_event(struct mon_reader_bin *rp, struct urb *urb,
 	unsigned int urb_length;
 	unsigned int offset;
 	unsigned int length;
+	unsigned int delta;
 	unsigned int ndesc, lendesc;
 	unsigned char dir;
 	struct mon_bin_hdr *ep;
@@ -537,8 +538,10 @@ static void mon_bin_event(struct mon_reader_bin *rp, struct urb *urb,
 	if (length != 0) {
 		ep->flag_data = mon_bin_get_data(rp, offset, urb, length);
 		if (ep->flag_data != 0) {	/* Yes, it's 0x00, not '0' */
-			ep->len_cap = 0;
-			mon_buff_area_shrink(rp, length);
+			delta = (ep->len_cap + PKT_ALIGN-1) & ~(PKT_ALIGN-1);
+			ep->len_cap -= length;
+			delta -= (ep->len_cap + PKT_ALIGN-1) & ~(PKT_ALIGN-1);
+			mon_buff_area_shrink(rp, delta);
 		}
 	} else {
 		ep->flag_data = data_tag;
diff --git a/drivers/usb/serial/option.c b/drivers/usb/serial/option.c
index cd44c68954df55e65dff18ae6f89c007d698b938..319aaf9725b37f99678381637fa605d29bfe3346 100644
--- a/drivers/usb/serial/option.c
+++ b/drivers/usb/serial/option.c
@@ -308,6 +308,7 @@ static int  option_resume(struct usb_serial *serial);
 
 #define DLINK_VENDOR_ID				0x1186
 #define DLINK_PRODUCT_DWM_652			0x3e04
+#define DLINK_PRODUCT_DWM_652_U5		0xce16
 
 #define QISDA_VENDOR_ID				0x1da5
 #define QISDA_PRODUCT_H21_4512			0x4512
@@ -586,6 +587,7 @@ static struct usb_device_id option_ids[] = {
 	{ USB_DEVICE_AND_INTERFACE_INFO(ZTE_VENDOR_ID, ZTE_PRODUCT_AC2726, 0xff, 0xff, 0xff) },
 	{ USB_DEVICE(BENQ_VENDOR_ID, BENQ_PRODUCT_H10) },
 	{ USB_DEVICE(DLINK_VENDOR_ID, DLINK_PRODUCT_DWM_652) },
+	{ USB_DEVICE(ALINK_VENDOR_ID, DLINK_PRODUCT_DWM_652_U5) }, /* Yes, ALINK_VENDOR_ID */
 	{ USB_DEVICE(QISDA_VENDOR_ID, QISDA_PRODUCT_H21_4512) },
 	{ USB_DEVICE(QISDA_VENDOR_ID, QISDA_PRODUCT_H21_4523) },
 	{ USB_DEVICE(QISDA_VENDOR_ID, QISDA_PRODUCT_H20_4515) },