diff --git a/drivers/usb/host/ehci-au1xxx.c b/drivers/usb/host/ehci-au1xxx.c
index c3a778bd359c9b883bd6e361e78951818fd3a280..59d208d94d4e772d5b1a8cc6f8a009d94132625f 100644
--- a/drivers/usb/host/ehci-au1xxx.c
+++ b/drivers/usb/host/ehci-au1xxx.c
@@ -113,6 +113,8 @@ static const struct hc_driver ehci_au1xxx_hc_driver = {
 	.bus_resume		= ehci_bus_resume,
 	.relinquish_port	= ehci_relinquish_port,
 	.port_handed_over	= ehci_port_handed_over,
+
+	.clear_tt_buffer_complete	= ehci_clear_tt_buffer_complete,
 };
 
 static int ehci_hcd_au1xxx_drv_probe(struct platform_device *pdev)
diff --git a/drivers/usb/host/ehci-fsl.c b/drivers/usb/host/ehci-fsl.c
index bf86809c5120795eac8521b68e2159d2fef37127..991174937db31ed5d829d6e1fdc0b3ea024e47bd 100644
--- a/drivers/usb/host/ehci-fsl.c
+++ b/drivers/usb/host/ehci-fsl.c
@@ -325,6 +325,8 @@ static const struct hc_driver ehci_fsl_hc_driver = {
 	.bus_resume = ehci_bus_resume,
 	.relinquish_port = ehci_relinquish_port,
 	.port_handed_over = ehci_port_handed_over,
+
+	.clear_tt_buffer_complete = ehci_clear_tt_buffer_complete,
 };
 
 static int ehci_fsl_drv_probe(struct platform_device *pdev)
diff --git a/drivers/usb/host/ehci-hcd.c b/drivers/usb/host/ehci-hcd.c
index 99c75603ec87143eebe77e1d8794457a87c03980..7d03549c3339ecc5ebdc5025db1d9f3b6d42f148 100644
--- a/drivers/usb/host/ehci-hcd.c
+++ b/drivers/usb/host/ehci-hcd.c
@@ -1003,6 +1003,8 @@ ehci_endpoint_disable (struct usb_hcd *hcd, struct usb_host_endpoint *ep)
 		schedule_timeout_uninterruptible(1);
 		goto rescan;
 	case QH_STATE_IDLE:		/* fully unlinked */
+		if (qh->clearing_tt)
+			goto idle_timeout;
 		if (list_empty (&qh->qtd_list)) {
 			qh_put (qh);
 			break;
diff --git a/drivers/usb/host/ehci-ixp4xx.c b/drivers/usb/host/ehci-ixp4xx.c
index a44bb4a949543d797f336827edb8ac6fa088d8ac..89b7c70c6ed6f015077a6a0233b78b080f581043 100644
--- a/drivers/usb/host/ehci-ixp4xx.c
+++ b/drivers/usb/host/ehci-ixp4xx.c
@@ -61,6 +61,8 @@ static const struct hc_driver ixp4xx_ehci_hc_driver = {
 #endif
 	.relinquish_port	= ehci_relinquish_port,
 	.port_handed_over	= ehci_port_handed_over,
+
+	.clear_tt_buffer_complete	= ehci_clear_tt_buffer_complete,
 };
 
 static int ixp4xx_ehci_probe(struct platform_device *pdev)
diff --git a/drivers/usb/host/ehci-orion.c b/drivers/usb/host/ehci-orion.c
index 770dd9aba62a9f07aabd9863e59fc4acae6a81dd..dc2ac613a9d1c34e2942ff55bf639fcb9d0be29b 100644
--- a/drivers/usb/host/ehci-orion.c
+++ b/drivers/usb/host/ehci-orion.c
@@ -165,6 +165,8 @@ static const struct hc_driver ehci_orion_hc_driver = {
 	.bus_resume = ehci_bus_resume,
 	.relinquish_port = ehci_relinquish_port,
 	.port_handed_over = ehci_port_handed_over,
+
+	.clear_tt_buffer_complete = ehci_clear_tt_buffer_complete,
 };
 
 static void __init
diff --git a/drivers/usb/host/ehci-pci.c b/drivers/usb/host/ehci-pci.c
index f3683e1da16134b3c20a6239b5edfd406af923aa..c2f1b7df918cd52ddd62385e3f02f5696d7f6f06 100644
--- a/drivers/usb/host/ehci-pci.c
+++ b/drivers/usb/host/ehci-pci.c
@@ -404,6 +404,8 @@ static const struct hc_driver ehci_pci_hc_driver = {
 	.bus_resume =		ehci_bus_resume,
 	.relinquish_port =	ehci_relinquish_port,
 	.port_handed_over =	ehci_port_handed_over,
+
+	.clear_tt_buffer_complete	= ehci_clear_tt_buffer_complete,
 };
 
 /*-------------------------------------------------------------------------*/
diff --git a/drivers/usb/host/ehci-ppc-of.c b/drivers/usb/host/ehci-ppc-of.c
index fbd272288fc2cf799ef1d075adea282dd01aa863..36f96da129f5c637208031ec04913be3f0cc6e67 100644
--- a/drivers/usb/host/ehci-ppc-of.c
+++ b/drivers/usb/host/ehci-ppc-of.c
@@ -79,6 +79,8 @@ static const struct hc_driver ehci_ppc_of_hc_driver = {
 #endif
 	.relinquish_port	= ehci_relinquish_port,
 	.port_handed_over	= ehci_port_handed_over,
+
+	.clear_tt_buffer_complete	= ehci_clear_tt_buffer_complete,
 };
 
 
diff --git a/drivers/usb/host/ehci-ps3.c b/drivers/usb/host/ehci-ps3.c
index 93f7035d00a16ad1da984e9f1b81c521afa79cba..1dee33b9139e65d1f8714234c7ecde9e7b3d0d24 100644
--- a/drivers/usb/host/ehci-ps3.c
+++ b/drivers/usb/host/ehci-ps3.c
@@ -75,6 +75,8 @@ static const struct hc_driver ps3_ehci_hc_driver = {
 #endif
 	.relinquish_port	= ehci_relinquish_port,
 	.port_handed_over	= ehci_port_handed_over,
+
+	.clear_tt_buffer_complete	= ehci_clear_tt_buffer_complete,
 };
 
 static int __devinit ps3_ehci_probe(struct ps3_system_bus_device *dev)
diff --git a/drivers/usb/host/ehci-q.c b/drivers/usb/host/ehci-q.c
index 68bf81e982d239fec2f2a38dc6b20d6129edde16..e3d2b627bfb33cc41021c6872807816b91d29f82 100644
--- a/drivers/usb/host/ehci-q.c
+++ b/drivers/usb/host/ehci-q.c
@@ -139,6 +139,55 @@ qh_refresh (struct ehci_hcd *ehci, struct ehci_qh *qh)
 
 /*-------------------------------------------------------------------------*/
 
+static void qh_link_async(struct ehci_hcd *ehci, struct ehci_qh *qh);
+
+static void ehci_clear_tt_buffer_complete(struct usb_hcd *hcd,
+		struct usb_host_endpoint *ep)
+{
+	struct ehci_hcd		*ehci = hcd_to_ehci(hcd);
+	struct ehci_qh		*qh = ep->hcpriv;
+	unsigned long		flags;
+
+	spin_lock_irqsave(&ehci->lock, flags);
+	qh->clearing_tt = 0;
+	if (qh->qh_state == QH_STATE_IDLE && !list_empty(&qh->qtd_list)
+			&& HC_IS_RUNNING(hcd->state))
+		qh_link_async(ehci, qh);
+	spin_unlock_irqrestore(&ehci->lock, flags);
+}
+
+static void ehci_clear_tt_buffer(struct ehci_hcd *ehci, struct ehci_qh *qh,
+		struct urb *urb, u32 token)
+{
+
+	/* If an async split transaction gets an error or is unlinked,
+	 * the TT buffer may be left in an indeterminate state.  We
+	 * have to clear the TT buffer.
+	 *
+	 * Note: this routine is never called for Isochronous transfers.
+	 */
+	if (urb->dev->tt && !usb_pipeint(urb->pipe) && !qh->clearing_tt) {
+#ifdef DEBUG
+		struct usb_device *tt = urb->dev->tt->hub;
+		dev_dbg(&tt->dev,
+			"clear tt buffer port %d, a%d ep%d t%08x\n",
+			urb->dev->ttport, urb->dev->devnum,
+			usb_pipeendpoint(urb->pipe), token);
+#endif /* DEBUG */
+		if (!ehci_is_TDI(ehci)
+				|| urb->dev->tt->hub !=
+				   ehci_to_hcd(ehci)->self.root_hub) {
+			if (usb_hub_clear_tt_buffer(urb) == 0)
+				qh->clearing_tt = 1;
+		} else {
+
+			/* REVISIT ARC-derived cores don't clear the root
+			 * hub TT buffer in this way...
+			 */
+		}
+	}
+}
+
 static int qtd_copy_status (
 	struct ehci_hcd *ehci,
 	struct urb *urb,
@@ -195,28 +244,6 @@ static int qtd_copy_status (
 			usb_pipeendpoint (urb->pipe),
 			usb_pipein (urb->pipe) ? "in" : "out",
 			token, status);
-
-		/* if async CSPLIT failed, try cleaning out the TT buffer */
-		if (status != -EPIPE
-				&& urb->dev->tt
-				&& !usb_pipeint(urb->pipe)
-				&& ((token & QTD_STS_MMF) != 0
-					|| QTD_CERR(token) == 0)
-				&& (!ehci_is_TDI(ehci)
-			                || urb->dev->tt->hub !=
-					   ehci_to_hcd(ehci)->self.root_hub)) {
-#ifdef DEBUG
-			struct usb_device *tt = urb->dev->tt->hub;
-			dev_dbg (&tt->dev,
-				"clear tt buffer port %d, a%d ep%d t%08x\n",
-				urb->dev->ttport, urb->dev->devnum,
-				usb_pipeendpoint (urb->pipe), token);
-#endif /* DEBUG */
-			/* REVISIT ARC-derived cores don't clear the root
-			 * hub TT buffer in this way...
-			 */
-			usb_hub_clear_tt_buffer(urb);
-		}
 	}
 
 	return status;
@@ -407,9 +434,16 @@ qh_completions (struct ehci_hcd *ehci, struct ehci_qh *qh)
 			/* qh unlinked; token in overlay may be most current */
 			if (state == QH_STATE_IDLE
 					&& cpu_to_hc32(ehci, qtd->qtd_dma)
-						== qh->hw_current)
+						== qh->hw_current) {
 				token = hc32_to_cpu(ehci, qh->hw_token);
 
+				/* An unlink may leave an incomplete
+				 * async transaction in the TT buffer.
+				 * We have to clear it.
+				 */
+				ehci_clear_tt_buffer(ehci, qh, urb, token);
+			}
+
 			/* force halt for unlinked or blocked qh, so we'll
 			 * patch the qh later and so that completions can't
 			 * activate it while we "know" it's stopped.
@@ -435,6 +469,13 @@ qh_completions (struct ehci_hcd *ehci, struct ehci_qh *qh)
 					&& (qtd->hw_alt_next
 						& EHCI_LIST_END(ehci)))
 				last_status = -EINPROGRESS;
+
+			/* As part of low/full-speed endpoint-halt processing
+			 * we must clear the TT buffer (11.17.5).
+			 */
+			if (unlikely(last_status != -EINPROGRESS &&
+					last_status != -EREMOTEIO))
+				ehci_clear_tt_buffer(ehci, qh, urb, token);
 		}
 
 		/* if we're removing something not at the queue head,
@@ -864,6 +905,10 @@ static void qh_link_async (struct ehci_hcd *ehci, struct ehci_qh *qh)
 	__hc32		dma = QH_NEXT(ehci, qh->qh_dma);
 	struct ehci_qh	*head;
 
+	/* Don't link a QH if there's a Clear-TT-Buffer pending */
+	if (unlikely(qh->clearing_tt))
+		return;
+
 	/* (re)start the async schedule? */
 	head = ehci->async;
 	timer_action_done (ehci, TIMER_ASYNC_OFF);
diff --git a/drivers/usb/host/ehci.h b/drivers/usb/host/ehci.h
index 90ad3395bb21f0f96923ab21431dc7c44165badb..2bfff30f4704f7521678239df30c07323e0d3e59 100644
--- a/drivers/usb/host/ehci.h
+++ b/drivers/usb/host/ehci.h
@@ -354,7 +354,9 @@ struct ehci_qh {
 	unsigned short		period;		/* polling interval */
 	unsigned short		start;		/* where polling starts */
 #define NO_FRAME ((unsigned short)~0)			/* pick new start */
+
 	struct usb_device	*dev;		/* access to TT */
+	unsigned		clearing_tt:1;	/* Clear-TT-Buf in progress */
 } __attribute__ ((aligned (32)));
 
 /*-------------------------------------------------------------------------*/