various dwc (OTG) driver fixups

Signed-off-by: Tim Harvey <tharvey@gateworks.com>
Signed-off-by: Imre Kaloz <kaloz@openwrt.org>

SVN-Revision: 39892

8 files changed, 442 insertions, 95 deletions

diff --git a/target/linux/cns3xxx/files/drivers/usb/dwc/otg_attr.c b/target/linux/cns3xxx/files/drivers/usb/dwc/otg_attr.c
index 343acd2517..45d06788a2 100644
--- a/target/linux/cns3xxx/files/drivers/usb/dwc/otg_attr.c
+++ b/target/linux/cns3xxx/files/drivers/usb/dwc/otg_attr.c
@@ -721,9 +721,10 @@ static ssize_t hcddump_show( struct device *_dev,
 			     char *buf)
 {
 #ifndef DWC_DEVICE_ONLY
-	struct platform_device *pdev = container_of(_dev, struct platform_device, dev); \
-	dwc_otg_device_t *otg_dev = platform_get_drvdata(pdev);		\
-	dwc_otg_hcd_dump_state(otg_dev->hcd);
+	struct platform_device *pdev = container_of(_dev, struct platform_device, dev);
+	struct usb_hcd *hcd = platform_get_drvdata(pdev);
+	dwc_otg_hcd_t *otg_dev = hcd_to_dwc_otg_hcd(hcd);
+	dwc_otg_hcd_dump_state(otg_dev);
 #endif
    	return sprintf( buf, "HCD Dump\n" );
 }
diff --git a/target/linux/cns3xxx/files/drivers/usb/dwc/otg_cil.c b/target/linux/cns3xxx/files/drivers/usb/dwc/otg_cil.c
index 42983afb8c..668d4d2412 100644
--- a/target/linux/cns3xxx/files/drivers/usb/dwc/otg_cil.c
+++ b/target/linux/cns3xxx/files/drivers/usb/dwc/otg_cil.c
@@ -66,7 +66,7 @@
 #include "otg_regs.h"
 #include "otg_cil.h"
 #include "otg_pcd.h"
-
+#include "otg_hcd.h"
 
 /**
  * This function is called to initialize the DWC_otg CSR data
@@ -1156,12 +1156,13 @@ void dwc_otg_core_host_init(dwc_otg_core_if_t *core_if)
 		DWC_DEBUGPL(DBG_HCDV, "%s: Halt channel %d\n", __func__, i);
 		do {
 			hcchar.d32 = dwc_read_reg32(&hc_regs->hcchar);
-			if (++count > 1000)
+			if (++count > 200)
 			{
 				DWC_ERROR("%s: Unable to clear halt on channel %d\n",
 					  __func__, i);
 				break;
 			}
+			udelay(100);
 		}
 		while (hcchar.b.chen);
 	}
@@ -1211,6 +1212,8 @@ void dwc_otg_hc_init(dwc_otg_core_if_t *core_if, dwc_hc_t *hc)
 	hc_intr_mask.b.chhltd = 1;
 	if (core_if->dma_enable) {
 		hc_intr_mask.b.ahberr = 1;
+		/* Always record the first nak interrupt for bulk
+		 * packets. */
 		if (hc->error_state && !hc->do_split &&
 			hc->ep_type != DWC_OTG_EP_TYPE_ISOC) {
 			hc_intr_mask.b.ack = 1;
@@ -1375,7 +1378,7 @@ void dwc_otg_hc_init(dwc_otg_core_if_t *core_if, dwc_hc_t *hc)
  * @param hc Host channel to halt.
  * @param halt_status Reason for halting the channel.
  */
-void dwc_otg_hc_halt(dwc_otg_core_if_t *core_if,
+void dwc_otg_hc_halt(dwc_otg_hcd_t *hcd,
 			 dwc_hc_t *hc,
 			 dwc_otg_halt_status_e halt_status)
 {
@@ -1385,6 +1388,7 @@ void dwc_otg_hc_halt(dwc_otg_core_if_t *core_if,
 	dwc_otg_hc_regs_t		*hc_regs;
 	dwc_otg_core_global_regs_t	*global_regs;
 	dwc_otg_host_global_regs_t	*host_global_regs;
+	dwc_otg_core_if_t *core_if = hcd->core_if;
 
 	hc_regs = core_if->host_if->hc_regs[hc->hc_num];
 	global_regs = core_if->core_global_regs;
@@ -1477,6 +1481,9 @@ void dwc_otg_hc_halt(dwc_otg_core_if_t *core_if,
 
 	hc->halt_status = halt_status;
 
+	if (!hc->halt_on_queue && !hc->halt_pending && hc->qh->nak_frame != 0xffff)
+		hcd->nakking_channels--;
+
 	if (hcchar.b.chen) {
 		hc->halt_pending = 1;
 		hc->halt_on_queue = 0;
@@ -1744,9 +1751,9 @@ void dwc_otg_hc_start_transfer(dwc_otg_core_if_t *core_if, dwc_hc_t *hc)
 	dwc_write_reg32(&hc_regs->hctsiz, hctsiz.d32);
 
 	DWC_DEBUGPL(DBG_HCDV, "%s: Channel %d\n", __func__, hc->hc_num);
-	DWC_DEBUGPL(DBG_HCDV, "	 Xfer Size: %d\n", hctsiz.b.xfersize);
-	DWC_DEBUGPL(DBG_HCDV, "	 Num Pkts: %d\n", hctsiz.b.pktcnt);
-	DWC_DEBUGPL(DBG_HCDV, "	 Start PID: %d\n", hctsiz.b.pid);
+	DWC_DEBUGPL(DBG_HCDV, "  Xfer Size: %d\n", hctsiz.b.xfersize);
+	DWC_DEBUGPL(DBG_HCDV, "  Num Pkts: %d\n", hctsiz.b.pktcnt);
+	DWC_DEBUGPL(DBG_HCDV, "  Start PID: %d\n", hctsiz.b.pid);
 
 	if (core_if->dma_enable) {
 		dwc_write_reg32(&hc_regs->hcdma, (uint32_t)hc->xfer_buff);
@@ -1774,6 +1781,10 @@ void dwc_otg_hc_start_transfer(dwc_otg_core_if_t *core_if, dwc_hc_t *hc)
 	/* Set host channel enable after all other setup is complete. */
 	hcchar.b.chen = 1;
 	hcchar.b.chdis = 0;
+
+	/* Memory Barrier before enabling channel ensure the channel is setup correct */
+	mb();
+
 	dwc_write_reg32(&hc_regs->hcchar, hcchar.d32);
 
 	hc->xfer_started = 1;
@@ -1786,7 +1797,7 @@ void dwc_otg_hc_start_transfer(dwc_otg_core_if_t *core_if, dwc_hc_t *hc)
 	}
 
 #ifdef DEBUG
-	/* Start a timer for this transfer. */
+	/* Start a timer for this transfer */
 	core_if->hc_xfer_timer[hc->hc_num].function = hc_xfer_timeout;
 	core_if->hc_xfer_info[hc->hc_num].core_if = core_if;
 	core_if->hc_xfer_info[hc->hc_num].hc = hc;
@@ -1844,6 +1855,10 @@ int dwc_otg_hc_continue_transfer(dwc_otg_core_if_t *core_if, dwc_hc_t *hc)
 		hcchar.b.chen = 1;
 		hcchar.b.chdis = 0;
 		DWC_DEBUGPL(DBG_HCDV, "	 IN xfer: hcchar = 0x%08x\n", hcchar.d32);
+
+		/* Memory Barrier before enabling channel ensure the channel is setup correct */
+		mb();
+
 		dwc_write_reg32(&hc_regs->hcchar, hcchar.d32);
 		hc->requests++;
 		return 1;
@@ -1891,6 +1906,10 @@ void dwc_otg_hc_do_ping(dwc_otg_core_if_t *core_if, dwc_hc_t *hc)
 	hcchar.d32 = dwc_read_reg32(&hc_regs->hcchar);
 	hcchar.b.chen = 1;
 	hcchar.b.chdis = 0;
+
+	/* Memory Barrier before enabling channel ensure the channel is setup correct */
+	mb();
+
 	dwc_write_reg32(&hc_regs->hcchar, hcchar.d32);
 }
 
@@ -2089,9 +2108,10 @@ void dwc_otg_ep_activate(dwc_otg_core_if_t *core_if, dwc_ep_t *ep)
 			if(core_if->dma_desc_enable) {
 				diepmsk.b.bna = 1;
 			}
+
 /*
 			if(core_if->dma_enable) {
-				doepmsk.b.nak = 1;
+				diepmsk.b.nak = 1;
 			}
 */
 			dwc_write_reg32(&dev_if->dev_global_regs->diepeachintmsk[ep->num], diepmsk.d32);
@@ -3567,6 +3587,7 @@ void dwc_otg_flush_tx_fifo(dwc_otg_core_if_t *core_if,
 			dwc_read_reg32(&global_regs->gnptxsts));
 			break;
 		}
+		udelay(1);
 	}
 	while (greset.b.txfflsh == 1);
 
@@ -3599,6 +3620,7 @@ void dwc_otg_flush_rx_fifo(dwc_otg_core_if_t *core_if)
 				greset.d32);
 			break;
 		}
+		udelay(1);
 	}
 	while (greset.b.rxfflsh == 1);
 
@@ -3640,6 +3662,7 @@ void dwc_otg_core_reset(dwc_otg_core_if_t *core_if)
 				greset.d32);
 			break;
 		}
+		udelay(1);
 	}
 	while (greset.b.csftrst == 1);
 
diff --git a/target/linux/cns3xxx/files/drivers/usb/dwc/otg_cil.h b/target/linux/cns3xxx/files/drivers/usb/dwc/otg_cil.h
index 463214b845..d1a4993766 100644
--- a/target/linux/cns3xxx/files/drivers/usb/dwc/otg_cil.h
+++ b/target/linux/cns3xxx/files/drivers/usb/dwc/otg_cil.h
@@ -45,6 +45,8 @@
 #include "linux/timer.h"
 #endif
 
+struct dwc_otg_hcd;
+
 /**
  * @file
  * This file contains the interface to the Core Interface Layer.
@@ -402,7 +404,7 @@ typedef struct dwc_otg_core_params
 	 */
 	int32_t dma_burst_size;	 /* Translate this to GAHBCFG values */
 //#define dwc_param_dma_burst_size_default 32
-#define dwc_param_dma_burst_size_default 1
+#define dwc_param_dma_burst_size_default 32
 
 	/**
 	 * Specifies the maximum speed of operation in host and device mode.
@@ -876,7 +878,7 @@ extern void dwc_otg_iso_ep_start_buf_transfer(dwc_otg_core_if_t *core_if, dwc_ep
  */
 /**@{*/
 extern void dwc_otg_hc_init(dwc_otg_core_if_t *_core_if, dwc_hc_t *_hc);
-extern void dwc_otg_hc_halt(dwc_otg_core_if_t *_core_if,
+extern void dwc_otg_hc_halt(struct dwc_otg_hcd *_hcd,
 				dwc_hc_t *_hc,
 				dwc_otg_halt_status_e _halt_status);
 extern void dwc_otg_hc_cleanup(dwc_otg_core_if_t *_core_if, dwc_hc_t *_hc);
diff --git a/target/linux/cns3xxx/files/drivers/usb/dwc/otg_hcd.c b/target/linux/cns3xxx/files/drivers/usb/dwc/otg_hcd.c
index e51b8c8d29..5f33fa530a 100644
--- a/target/linux/cns3xxx/files/drivers/usb/dwc/otg_hcd.c
+++ b/target/linux/cns3xxx/files/drivers/usb/dwc/otg_hcd.c
@@ -176,8 +176,10 @@ static void kill_urbs_in_qh_list(dwc_otg_hcd_t *hcd, struct list_head *qh_list)
 		     qtd_item = qh->qtd_list.next) {
 			qtd = list_entry(qtd_item, dwc_otg_qtd_t, qtd_list_entry);
 			if (qtd->urb != NULL) {
+				SPIN_UNLOCK_IRQRESTORE(&hcd->lock, flags);
 				dwc_otg_hcd_complete_urb(hcd, qtd->urb,
 							 -ETIMEDOUT);
+				SPIN_LOCK_IRQSAVE(&hcd->lock, flags);
 			}
 			dwc_otg_hcd_qtd_remove_and_free(hcd, qtd);
 		}
@@ -589,6 +591,7 @@ static void hcd_reinit(dwc_otg_hcd_t *hcd)
 	hcd->non_periodic_qh_ptr = &hcd->non_periodic_sched_active;
 	hcd->non_periodic_channels = 0;
 	hcd->periodic_channels = 0;
+	hcd->nakking_channels = 0;
 
 	/*
 	 * Put all channels in the free channel list and clean up channel
@@ -853,10 +856,10 @@ static void dump_channel_info(dwc_otg_hcd_t *hcd,
 //OTG host require the DMA addr is DWORD-aligned,
 //patch it if the buffer is not DWORD-aligned
 inline
-void hcd_check_and_patch_dma_addr(struct urb *urb){
+int hcd_check_and_patch_dma_addr(struct urb *urb){
 
 	if((!urb->transfer_buffer)||!urb->transfer_dma||urb->transfer_dma==0xffffffff)
-		return;
+		return 0;
 
 	if(((u32)urb->transfer_buffer)& 0x3){
 		/*
@@ -881,11 +884,12 @@ void hcd_check_and_patch_dma_addr(struct urb *urb){
 				kfree(urb->aligned_transfer_buffer);
 			}
 			urb->aligned_transfer_buffer=kmalloc(urb->aligned_transfer_buffer_length,GFP_KERNEL|GFP_DMA|GFP_ATOMIC);
-			urb->aligned_transfer_dma=dma_map_single(NULL,(void *)(urb->aligned_transfer_buffer),(urb->aligned_transfer_buffer_length),DMA_FROM_DEVICE);
 			if(!urb->aligned_transfer_buffer){
 				DWC_ERROR("Cannot alloc required buffer!!\n");
-				BUG();
+				//BUG();
+				return -1;
 			}
+			urb->aligned_transfer_dma=dma_map_single(NULL,(void *)(urb->aligned_transfer_buffer),(urb->aligned_transfer_buffer_length),DMA_FROM_DEVICE);
 			//printk(" new allocated aligned_buf=%.8x aligned_buf_len=%d\n", (u32)urb->aligned_transfer_buffer, urb->aligned_transfer_buffer_length);
 		}
 		urb->transfer_dma=urb->aligned_transfer_dma;
@@ -894,6 +898,7 @@ void hcd_check_and_patch_dma_addr(struct urb *urb){
 			dma_sync_single_for_device(NULL,urb->transfer_dma,urb->transfer_buffer_length,DMA_TO_DEVICE);
 		}
 	}
+	return 0;
 }
 
 
@@ -910,7 +915,15 @@ int dwc_otg_hcd_urb_enqueue(struct usb_hcd *hcd,
 	int retval = 0;
 	dwc_otg_hcd_t *dwc_otg_hcd = hcd_to_dwc_otg_hcd(hcd);
 	dwc_otg_qtd_t *qtd;
+	unsigned long flags;
+
+	SPIN_LOCK_IRQSAVE(&dwc_otg_hcd->lock, flags);
+
+	if (urb->hcpriv != NULL) {
+		SPIN_UNLOCK_IRQRESTORE(&dwc_otg_hcd->lock, flags);
+		return -ENOMEM;
 
+	}
 #ifdef DEBUG
 	if (CHK_DEBUG_LEVEL(DBG_HCDV | DBG_HCD_URB)) {
 		dump_urb_info(urb, "dwc_otg_hcd_urb_enqueue");
@@ -918,13 +931,19 @@ int dwc_otg_hcd_urb_enqueue(struct usb_hcd *hcd,
 #endif
 	if (!dwc_otg_hcd->flags.b.port_connect_status) {
 		/* No longer connected. */
+		SPIN_UNLOCK_IRQRESTORE(&dwc_otg_hcd->lock, flags);
 		return -ENODEV;
 	}
 
-	hcd_check_and_patch_dma_addr(urb);
+	if (hcd_check_and_patch_dma_addr(urb)) {
+		DWC_ERROR("Unable to check and patch dma addr\n");
+		SPIN_UNLOCK_IRQRESTORE(&dwc_otg_hcd->lock, flags);
+		return -ENOMEM;
+	}
 	qtd = dwc_otg_hcd_qtd_create(urb);
 	if (qtd == NULL) {
 		DWC_ERROR("DWC OTG HCD URB Enqueue failed creating QTD\n");
+		SPIN_UNLOCK_IRQRESTORE(&dwc_otg_hcd->lock, flags);
 		return -ENOMEM;
 	}
 
@@ -934,7 +953,7 @@ int dwc_otg_hcd_urb_enqueue(struct usb_hcd *hcd,
 			  "Error status %d\n", retval);
 		dwc_otg_hcd_qtd_free(qtd);
 	}
-
+	SPIN_UNLOCK_IRQRESTORE(&dwc_otg_hcd->lock, flags);
 	return retval;
 }
 
@@ -948,6 +967,7 @@ int dwc_otg_hcd_urb_dequeue(struct usb_hcd *hcd,
 	dwc_otg_qtd_t *urb_qtd;
 	dwc_otg_qh_t *qh;
 	struct usb_host_endpoint *ep = dwc_urb_to_endpoint(urb);
+	int rc;
 
 	DWC_DEBUGPL(DBG_HCD, "DWC OTG HCD URB Dequeue\n");
 
@@ -958,10 +978,6 @@ int dwc_otg_hcd_urb_dequeue(struct usb_hcd *hcd,
 	urb_qtd = (dwc_otg_qtd_t *)urb->hcpriv;
 	qh = (dwc_otg_qh_t *)ep->hcpriv;
 
-	if (urb_qtd == NULL) {
-		SPIN_UNLOCK_IRQRESTORE(&dwc_otg_hcd->lock, flags);
-		return 0;
-	}
 #ifdef DEBUG
 	if (CHK_DEBUG_LEVEL(DBG_HCDV | DBG_HCD_URB)) {
 		dump_urb_info(urb, "dwc_otg_hcd_urb_dequeue");
@@ -971,7 +987,7 @@ int dwc_otg_hcd_urb_dequeue(struct usb_hcd *hcd,
 	}
 #endif
 
-	if (urb_qtd == qh->qtd_in_process) {
+	if (qh && urb_qtd == qh->qtd_in_process) {
 		/* The QTD is in process (it has been assigned to a channel). */
 
 		if (dwc_otg_hcd->flags.b.port_connect_status) {
@@ -982,7 +998,7 @@ int dwc_otg_hcd_urb_dequeue(struct usb_hcd *hcd,
 			 * written to halt the channel since the core is in
 			 * device mode.
 			 */
-			dwc_otg_hc_halt(dwc_otg_hcd->core_if, qh->channel,
+			dwc_otg_hc_halt(dwc_otg_hcd, qh->channel,
 					DWC_OTG_HC_XFER_URB_DEQUEUE);
 		}
 	}
@@ -992,22 +1008,28 @@ int dwc_otg_hcd_urb_dequeue(struct usb_hcd *hcd,
 	 * schedule if it has any remaining QTDs.
 	 */
 	dwc_otg_hcd_qtd_remove_and_free(dwc_otg_hcd, urb_qtd);
-	if (urb_qtd == qh->qtd_in_process) {
-		/* Note that dwc_otg_hcd_qh_deactivate() locks the spin_lock again */
-		SPIN_UNLOCK_IRQRESTORE(&dwc_otg_hcd->lock, flags);
+	if (qh && urb_qtd == qh->qtd_in_process) {
 		dwc_otg_hcd_qh_deactivate(dwc_otg_hcd, qh, 0);
 		qh->channel = NULL;
 		qh->qtd_in_process = NULL;
 	} else {
-		if (list_empty(&qh->qtd_list))
+		if (qh && list_empty(&qh->qtd_list)) {
 			dwc_otg_hcd_qh_remove(dwc_otg_hcd, qh);
-		SPIN_UNLOCK_IRQRESTORE(&dwc_otg_hcd->lock, flags);
+		}
 	}
 
+
+	rc = usb_hcd_check_unlink_urb(hcd, urb, status);
+
+	if (!rc) {
+		usb_hcd_unlink_urb_from_ep(hcd, urb);
+	}
 	urb->hcpriv = NULL;
+	SPIN_UNLOCK_IRQRESTORE(&dwc_otg_hcd->lock, flags);
 
-	/* Higher layer software sets URB status. */
-	usb_hcd_giveback_urb(hcd, urb, status);
+	if (!rc) {
+		usb_hcd_giveback_urb(hcd, urb, status);
+	}
 	if (CHK_DEBUG_LEVEL(DBG_HCDV | DBG_HCD_URB)) {
 		DWC_PRINT("Called usb_hcd_giveback_urb()\n");
 		DWC_PRINT("  urb->status = %d\n", urb->status);
@@ -2035,15 +2057,19 @@ static void assign_and_init_hc(dwc_otg_hcd_t *hcd, dwc_otg_qh_t *qh)
 	dwc_otg_qtd_t	*qtd;
 	struct urb	*urb;
 
-	DWC_DEBUGPL(DBG_HCDV, "%s(%p,%p)\n", __func__, hcd, qh);
-
+	DWC_DEBUGPL(DBG_HCD_FLOOD, "%s(%p,%p)\n", __func__, hcd, qh);
 	hc = list_entry(hcd->free_hc_list.next, dwc_hc_t, hc_list_entry);
 
+	qtd = list_entry(qh->qtd_list.next, dwc_otg_qtd_t, qtd_list_entry);
+	urb = qtd->urb;
+
+	if (!urb){
+		return;
+	}
+
 	/* Remove the host channel from the free list. */
 	list_del_init(&hc->hc_list_entry);
 
-	qtd = list_entry(qh->qtd_list.next, dwc_otg_qtd_t, qtd_list_entry);
-	urb = qtd->urb;
 	qh->channel = hc;
 	qh->qtd_in_process = qtd;
 
@@ -2202,16 +2228,24 @@ static void assign_and_init_hc(dwc_otg_hcd_t *hcd, dwc_otg_qh_t *qh)
 dwc_otg_transaction_type_e dwc_otg_hcd_select_transactions(dwc_otg_hcd_t *hcd)
 {
 	struct list_head 		*qh_ptr;
-	dwc_otg_qh_t 			*qh;
+	dwc_otg_qh_t 			*qh = NULL;
 	int				num_channels;
 	dwc_otg_transaction_type_e	ret_val = DWC_OTG_TRANSACTION_NONE;
+	uint16_t      cur_frame = dwc_otg_hcd_get_frame_number(dwc_otg_hcd_to_hcd(hcd));
+	unsigned long flags;
+	int include_nakd, channels_full;
+	/* This condition has once been observed, but the cause was
+	 * never determined. Check for it here, to collect debug data if
+	 * it occurs again. */
+	WARN_ON_ONCE(hcd->non_periodic_channels < 0);
+	check_nakking(hcd, __FUNCTION__,  "start");
 
 #ifdef DEBUG_SOF
 	DWC_DEBUGPL(DBG_HCD, "  Select Transactions\n");
 #endif
 
-	spin_lock(&hcd->lock);
-	/* Process entries in the periodic ready list. */
+	SPIN_LOCK_IRQSAVE(&hcd->lock, flags);
+		/* Process entries in the periodic ready list. */
 	qh_ptr = hcd->periodic_sched_ready.next;
 	while (qh_ptr != &hcd->periodic_sched_ready &&
 	       !list_empty(&hcd->free_hc_list)) {
@@ -2234,37 +2268,140 @@ dwc_otg_transaction_type_e dwc_otg_hcd_select_transactions(dwc_otg_hcd_t *hcd)
 	 * schedule. Some free host channels may not be used if they are
 	 * reserved for periodic transfers.
 	 */
-	qh_ptr = hcd->non_periodic_sched_inactive.next;
 	num_channels = hcd->core_if->core_params->host_channels;
-	while (qh_ptr != &hcd->non_periodic_sched_inactive &&
-	       (hcd->non_periodic_channels <
-		num_channels - hcd->periodic_channels) &&
-	       !list_empty(&hcd->free_hc_list)) {
 
-		qh = list_entry(qh_ptr, dwc_otg_qh_t, qh_list_entry);
-		assign_and_init_hc(hcd, qh);
+	/* Go over the queue twice: Once while not including nak'd
+	 * entries, one while including them. This is so a retransmit of
+	 * an entry that has received a nak is scheduled only after all
+	 * new entries.
+	 */
+	channels_full = 0;
+	for (include_nakd = 0; include_nakd < 2 && !channels_full; ++include_nakd) {
+	    qh_ptr = hcd->non_periodic_sched_inactive.next;
+	  while (qh_ptr != &hcd->non_periodic_sched_inactive) {
+			qh = list_entry(qh_ptr, dwc_otg_qh_t, qh_list_entry);
+			qh_ptr = qh_ptr->next;
 
-		/*
-		 * Move the QH from the non-periodic inactive schedule to the
-		 * non-periodic active schedule.
-		 */
-		qh_ptr = qh_ptr->next;
-		list_move(&qh->qh_list_entry, &hcd->non_periodic_sched_active);
+			/* If a nak'd frame is in the queue for 100ms, forget
+		 	* about its nak status, to prevent the situation where
+		 	* a nak'd frame never gets resubmitted because there
+		 	* are continously non-nakking tranfsfers available.
+		 	*/
+			if (qh->nak_frame != 0xffff &&
+		    	dwc_frame_num_gt(cur_frame, qh->nak_frame + 800))
+				qh->nak_frame = 0xffff;
 
-		if (ret_val == DWC_OTG_TRANSACTION_NONE) {
-			ret_val = DWC_OTG_TRANSACTION_NON_PERIODIC;
-		} else {
-			ret_val = DWC_OTG_TRANSACTION_ALL;
+			/* In the first pass, ignore NAK'd retransmit
+		 	* alltogether, to give them lower priority. */
+			if (!include_nakd && qh->nak_frame != 0xffff)
+				continue;
+
+			/*
+			* Check to see if this is a NAK'd retransmit, in which case ignore for retransmission
+			* we hold off on bulk retransmissions to reduce NAK interrupt overhead for
+			* cheeky devices that just hold off using NAKs
+			*/
+			if (dwc_full_frame_num(qh->nak_frame) == dwc_full_frame_num(dwc_otg_hcd_get_frame_number(dwc_otg_hcd_to_hcd(hcd))))
+				continue;
+
+			/* Ok, we found a candidate for scheduling. Is there a
+		 	* free channel? */
+			if (hcd->non_periodic_channels >=
+		    	num_channels - hcd->periodic_channels ||
+	            	list_empty(&hcd->free_hc_list)) {
+				channels_full = 1;
+				break;
+			}
+
+			/* When retrying a NAK'd transfer, we give it a fair
+		 	* chance of completing again. */
+			qh->nak_frame = 0xffff;
+			assign_and_init_hc(hcd, qh);
+
+			/*
+		 	* Move the QH from the non-periodic inactive schedule to the
+		 	* non-periodic active schedule.
+		 	*/
+			list_move(&qh->qh_list_entry, &hcd->non_periodic_sched_active);
+
+			if (ret_val == DWC_OTG_TRANSACTION_NONE) {
+				ret_val = DWC_OTG_TRANSACTION_NON_PERIODIC;
+			} else {
+				ret_val = DWC_OTG_TRANSACTION_ALL;
+			}
+
+			hcd->non_periodic_channels++;
 		}
+		if (hcd->core_if->dma_enable && channels_full &&
+			  hcd->periodic_channels + hcd->nakking_channels >= num_channels) {
+			/* There are items queued, but all channels are either
+			 * reserved for periodic or have received NAKs. This
+			 * means that it could take an indefinite amount of time
+			 * before a channel is actually freed (since in DMA
+			 * mode, the hardware takes care of retries), so we take
+			 * action here by forcing a nakking channel to halt to
+			 * give other transfers a chance to run. */
+			dwc_otg_qtd_t *qtd = list_entry(qh->qtd_list.next, dwc_otg_qtd_t, qtd_list_entry);
+			struct urb *urb = qtd->urb;
+			dwc_hc_t *hc = dwc_otg_halt_nakking_channel(hcd);
+
+			if (hc)
+			  DWC_DEBUGPL(DBG_HCD "Out of Host Channels for non-periodic transfer - Halting channel %d (dev %d ep%d%s) to service qh %p (dev %d ep%d%s)\n", hc->hc_num, hc->dev_addr, hc->ep_num, (hc->ep_is_in ? "in" : "out"), qh, usb_pipedevice(urb->pipe), usb_pipeendpoint(urb->pipe), (usb_pipein(urb->pipe) != 0) ? "in" : "out");
 
-		hcd->non_periodic_channels++;
+		}
 	}
-	spin_unlock(&hcd->lock);
+
+	SPIN_UNLOCK_IRQRESTORE(&hcd->lock, flags);
 
 	return ret_val;
 }
 
 /**
+ * Halt a bulk channel that is blocking on NAKs to free up space.
+ *
+ * This will decrement hcd->nakking_channels immediately, but
+ * hcd->non_periodic_channels is not decremented until the channel is
+ * actually halted.
+ *
+ * Returns the halted channel.
+ */
+dwc_hc_t *dwc_otg_halt_nakking_channel(dwc_otg_hcd_t *hcd) {
+ int num_channels, i;
+ uint16_t cur_frame;
+
+ cur_frame = dwc_otg_hcd_get_frame_number(dwc_otg_hcd_to_hcd(hcd));
+ num_channels = hcd->core_if->core_params->host_channels;
+
+ for (i = 0; i < num_channels; i++) {
+   int channel = (hcd->last_channel_halted + 1 + i) % num_channels;
+   dwc_hc_t *hc = hcd->hc_ptr_array[channel];
+   if (hc->xfer_started
+       && !hc->halt_on_queue
+       && !hc->halt_pending
+       && hc->qh->nak_frame != 0xffff) {
+     dwc_otg_hc_halt(hcd, hc, DWC_OTG_HC_XFER_NAK);
+     /* Store the last channel halted to
+      * fairly rotate the channel to halt.
+      * This prevent the scenario where there
+      * are three blocking endpoints and only
+      * two free host channels, where the
+      * blocking endpoint that gets hc 3 will
+      * never be halted, while the other two
+      * endpoints will be fighting over the
+      * other host channel. */
+     hcd->last_channel_halted = channel;
+     /* Update nak_frame, so this frame is
+      * kept at low priority for a period of
+      * time starting now. */
+     hc->qh->nak_frame = cur_frame;
+     return hc;
+   }
+ }
+ dwc_otg_hcd_dump_state(hcd);
+ return NULL;
+}
+
+/**
  * Attempts to queue a single transaction request for a host channel
  * associated with either a periodic or non-periodic transfer. This function
  * assumes that there is space available in the appropriate request queue. For
@@ -2298,7 +2435,7 @@ static int queue_transaction(dwc_otg_hcd_t *hcd,
 		/* Don't queue a request if the channel has been halted. */
 		retval = 0;
 	} else if (hc->halt_on_queue) {
-		dwc_otg_hc_halt(hcd->core_if, hc, hc->halt_status);
+		dwc_otg_hc_halt(hcd, hc, hc->halt_status);
 		retval = 0;
 	} else if (hc->do_ping) {
 		if (!hc->xfer_started) {
@@ -2446,12 +2583,12 @@ static void process_periodic_channels(dwc_otg_hcd_t *hcd)
 	dwc_otg_host_global_regs_t *host_regs;
 	host_regs = hcd->core_if->host_if->host_global_regs;
 
-	DWC_DEBUGPL(DBG_HCDV, "Queue periodic transactions\n");
+	DWC_DEBUGPL(DBG_HCD_FLOOD, "Queue periodic transactions\n");
 #ifdef DEBUG
 	tx_status.d32 = dwc_read_reg32(&host_regs->hptxsts);
-	DWC_DEBUGPL(DBG_HCDV, "  P Tx Req Queue Space Avail (before queue): %d\n",
+	DWC_DEBUGPL(DBG_HCD_FLOOD, "  P Tx Req Queue Space Avail (before queue): %d\n",
 		    tx_status.b.ptxqspcavail);
-	DWC_DEBUGPL(DBG_HCDV, "  P Tx FIFO Space Avail (before queue): %d\n",
+	DWC_DEBUGPL(DBG_HCD_FLOOD, "  P Tx FIFO Space Avail (before queue): %d\n",
 		    tx_status.b.ptxfspcavail);
 #endif
 
@@ -2586,7 +2723,12 @@ void dwc_otg_hcd_queue_transactions(dwc_otg_hcd_t *hcd,
  */
 void dwc_otg_hcd_complete_urb(dwc_otg_hcd_t *hcd, struct urb *urb, int status)
 {
+	unsigned long		flags;
+
+	SPIN_LOCK_IRQSAVE(&hcd->lock, flags);
+
 #ifdef DEBUG
+
 	if (CHK_DEBUG_LEVEL(DBG_HCDV | DBG_HCD_URB)) {
 		DWC_PRINT("%s: urb %p, device %d, ep %d %s, status=%d\n",
 			  __func__, urb, usb_pipedevice(urb->pipe),
@@ -2609,10 +2751,12 @@ void dwc_otg_hcd_complete_urb(dwc_otg_hcd_t *hcd, struct urb *urb, int status)
 		memcpy(urb->transfer_buffer,urb->aligned_transfer_buffer,urb->actual_length);
 	}
 
-
+	usb_hcd_unlink_urb_from_ep(dwc_otg_hcd_to_hcd(hcd), urb);
 	urb->status = status;
 	urb->hcpriv = NULL;
+	SPIN_UNLOCK_IRQRESTORE(&hcd->lock, flags);
 	usb_hcd_giveback_urb(dwc_otg_hcd_to_hcd(hcd), urb, status);
+
 }
 
 /*
@@ -2674,7 +2818,7 @@ void dwc_otg_hcd_dump_state(dwc_otg_hcd_t *hcd)
 	DWC_PRINT("  Num channels: %d\n", num_channels);
 	for (i = 0; i < num_channels; i++) {
 		dwc_hc_t *hc = hcd->hc_ptr_array[i];
-		DWC_PRINT("  Channel %d:\n", i);
+		DWC_PRINT("  Channel %d: %p\n", i, hc);
 		DWC_PRINT("    dev_addr: %d, ep_num: %d, ep_is_in: %d\n",
 			  hc->dev_addr, hc->ep_num, hc->ep_is_in);
 		DWC_PRINT("    speed: %d\n", hc->speed);
@@ -2696,6 +2840,8 @@ void dwc_otg_hcd_dump_state(dwc_otg_hcd_t *hcd)
 		DWC_PRINT("    xact_pos: %d\n", hc->xact_pos);
 		DWC_PRINT("    requests: %d\n", hc->requests);
 		DWC_PRINT("    qh: %p\n", hc->qh);
+		if (hc->qh)
+			DWC_PRINT("    nak_frame: %x\n", hc->qh->nak_frame);
 		if (hc->xfer_started) {
 			hfnum_data_t hfnum;
 			hcchar_data_t hcchar;
@@ -2735,6 +2881,8 @@ void dwc_otg_hcd_dump_state(dwc_otg_hcd_t *hcd)
 	}
 	DWC_PRINT("  non_periodic_channels: %d\n", hcd->non_periodic_channels);
 	DWC_PRINT("  periodic_channels: %d\n", hcd->periodic_channels);
+	DWC_PRINT("  nakking_channels: %d\n", hcd->nakking_channels);
+	DWC_PRINT("  last_channel_halted: %d\n", hcd->last_channel_halted);
 	DWC_PRINT("  periodic_usecs: %d\n", hcd->periodic_usecs);
 	np_tx_status.d32 = dwc_read_reg32(&hcd->core_if->core_global_regs->gnptxsts);
 	DWC_PRINT("  NP Tx Req Queue Space Avail: %d\n", np_tx_status.b.nptxqspcavail);
diff --git a/target/linux/cns3xxx/files/drivers/usb/dwc/otg_hcd.h b/target/linux/cns3xxx/files/drivers/usb/dwc/otg_hcd.h
index 935f353b92..cef2879329 100644
--- a/target/linux/cns3xxx/files/drivers/usb/dwc/otg_hcd.h
+++ b/target/linux/cns3xxx/files/drivers/usb/dwc/otg_hcd.h
@@ -194,6 +194,11 @@ typedef struct dwc_otg_qh {
 	 */
 	uint16_t		sched_frame;
 
+	/*
+	 * Frame a NAK was received on this queue head, used to minimise NAK retransmission
+	 */
+	uint16_t nak_frame;
+
 	/** (micro)frame at which last start split was initialized. */
 	uint16_t		start_split_frame;
 
@@ -328,6 +333,21 @@ typedef struct dwc_otg_hcd {
 	struct list_head	free_hc_list;
 
 	/**
+	 * The number of bulk channels in the active schedule that do
+	 * not have a halt pending or queued but received at least one
+	 * nak and thus are probably blocking a host channel.
+	 *
+	 * This number is included in non_perodic_channels as well.
+	 */
+	int nakking_channels;
+
+	/**
+	 * The number of the last host channel that was halted to free
+	 * up a host channel.
+	 */
+	int last_channel_halted;
+
+	/**
 	 * Number of host channels assigned to periodic transfers. Currently
 	 * assuming that there is a dedicated host channel for each periodic
 	 * transaction and at least one host channel available for
@@ -452,6 +472,8 @@ extern void dwc_otg_hcd_queue_transactions(dwc_otg_hcd_t *hcd,
 					   dwc_otg_transaction_type_e tr_type);
 extern void dwc_otg_hcd_complete_urb(dwc_otg_hcd_t *_hcd, struct urb *urb,
 				     int status);
+extern dwc_hc_t *dwc_otg_halt_nakking_channel(dwc_otg_hcd_t *hcd);
+
 /** @} */
 
 /** @name Interrupt Handler Functions */
@@ -612,6 +634,40 @@ static inline uint16_t dwc_micro_frame_num(uint16_t frame)
 	return frame & 0x7;
 }
 
+/* Perform some sanity checks on nakking / non_perodic channel states. */
+static inline int check_nakking(struct dwc_otg_hcd *hcd, const char *func, const char* context) {
+#ifdef DEBUG
+	int nakking = 0, non_periodic = 0, i;
+	int num_channels = hcd->core_if->core_params->host_channels;
+	for (i = 0; i < num_channels; i++) {
+		dwc_hc_t *hc = hcd->hc_ptr_array[i];
+		if (hc->xfer_started
+		    && (hc->ep_type == DWC_OTG_EP_TYPE_BULK
+			|| hc->ep_type == DWC_OTG_EP_TYPE_CONTROL)) {
+				non_periodic++;
+		}
+		if (hc->xfer_started
+		    && !hc->halt_on_queue
+		    && !hc->halt_pending
+		    && hc->qh->nak_frame != 0xffff) {
+			nakking++;
+		}
+	}
+
+	if (nakking != hcd->nakking_channels
+	    || nakking > hcd->non_periodic_channels
+	    || non_periodic != hcd->non_periodic_channels) {
+		printk("%s/%s: Inconsistent nakking state\n", func, context);
+		printk("non_periodic: %d, real %d, nakking: %d, real %d\n", hcd->non_periodic_channels, non_periodic, hcd->nakking_channels, nakking);
+		dwc_otg_hcd_dump_state(hcd);
+		WARN_ON(1);
+		return 1;
+	}
+#endif
+	return 0;
+}
+
+
 #ifdef DEBUG
 /**
  * Macro to sample the remaining PHY clocks left in the current frame. This
diff --git a/target/linux/cns3xxx/files/drivers/usb/dwc/otg_hcd_intr.c b/target/linux/cns3xxx/files/drivers/usb/dwc/otg_hcd_intr.c
index e63b8630d2..532ff7acff 100644
--- a/target/linux/cns3xxx/files/drivers/usb/dwc/otg_hcd_intr.c
+++ b/target/linux/cns3xxx/files/drivers/usb/dwc/otg_hcd_intr.c
@@ -65,14 +65,14 @@ int32_t dwc_otg_hcd_handle_intr(dwc_otg_hcd_t *dwc_otg_hcd)
 # ifndef DEBUG_SOF
 		if (gintsts.d32 != DWC_SOF_INTR_MASK)
 # endif
-			DWC_DEBUGPL(DBG_HCD, "\n");
+			DWC_DEBUGPL(DBG_HCD_FLOOD, "\n");
 #endif
 
 #ifdef DEBUG
 # ifndef DEBUG_SOF
 		if (gintsts.d32 != DWC_SOF_INTR_MASK)
 # endif
-			DWC_DEBUGPL(DBG_HCD, "DWC OTG HCD Interrupt Detected gintsts&gintmsk=0x%08x\n", gintsts.d32);
+			DWC_DEBUGPL(DBG_HCD_FLOOD, "DWC OTG HCD Interrupt Detected gintsts&gintmsk=0x%08x\n", gintsts.d32);
 #endif
 		if (gintsts.b.usbreset) {
 			DWC_PRINT("Usb Reset In Host Mode\n");
@@ -103,10 +103,10 @@ int32_t dwc_otg_hcd_handle_intr(dwc_otg_hcd_t *dwc_otg_hcd)
 		if (gintsts.d32 != DWC_SOF_INTR_MASK)
 # endif
 		{
-			DWC_DEBUGPL(DBG_HCD, "DWC OTG HCD Finished Servicing Interrupts\n");
-			DWC_DEBUGPL(DBG_HCDV, "DWC OTG HCD gintsts=0x%08x\n",
+			DWC_DEBUGPL(DBG_HCD_FLOOD, "DWC OTG HCD Finished Servicing Interrupts\n");
+			DWC_DEBUGPL(DBG_HCD_FLOOD, "DWC OTG HCD gintsts=0x%08x\n",
 				    dwc_read_reg32(&global_regs->gintsts));
-			DWC_DEBUGPL(DBG_HCDV, "DWC OTG HCD gintmsk=0x%08x\n",
+			DWC_DEBUGPL(DBG_HCD_FLOOD, "DWC OTG HCD gintmsk=0x%08x\n",
 				    dwc_read_reg32(&global_regs->gintmsk));
 		}
 #endif
@@ -115,7 +115,7 @@ int32_t dwc_otg_hcd_handle_intr(dwc_otg_hcd_t *dwc_otg_hcd)
 # ifndef DEBUG_SOF
 	if (gintsts.d32 != DWC_SOF_INTR_MASK)
 # endif
-		DWC_DEBUGPL(DBG_HCD, "\n");
+		DWC_DEBUGPL(DBG_HCD_FLOOD, "\n");
 #endif
 
 	}
@@ -534,7 +534,7 @@ static int update_urb_state_xfer_comp(dwc_hc_t *hc,
 						     DWC_OTG_HC_XFER_COMPLETE,
 						     &short_read);
 
-	if (short_read || urb->actual_length == urb->transfer_buffer_length) {
+	if (short_read || urb->actual_length >= urb->transfer_buffer_length) {
 		xfer_done = 1;
 		if (short_read && (urb->transfer_flags & URB_SHORT_NOT_OK)) {
 			urb->status = -EREMOTEIO;
@@ -551,6 +551,7 @@ static int update_urb_state_xfer_comp(dwc_hc_t *hc,
 			    __func__, (hc->ep_is_in ? "IN" : "OUT"), hc->hc_num);
 		DWC_DEBUGPL(DBG_HCDV, "  hc->xfer_len %d\n", hc->xfer_len);
 		DWC_DEBUGPL(DBG_HCDV, "  hctsiz.xfersize %d\n", hctsiz.b.xfersize);
+		DWC_DEBUGPL(DBG_HCDV, "  urb %p\n", urb);
 		DWC_DEBUGPL(DBG_HCDV, "  urb->transfer_buffer_length %d\n",
 			    urb->transfer_buffer_length);
 		DWC_DEBUGPL(DBG_HCDV, "  urb->actual_length %d\n", urb->actual_length);
@@ -603,10 +604,12 @@ static void deactivate_qh(dwc_otg_hcd_t *hcd,
 {
 	int continue_split = 0;
 	dwc_otg_qtd_t *qtd;
+	unsigned long flags;
 
 	DWC_DEBUGPL(DBG_HCDV, "  %s(%p,%p,%d)\n", __func__, hcd, qh, free_qtd);
 
-	spin_lock(&hcd->lock);
+	SPIN_LOCK_IRQSAVE(&hcd->lock, flags);
+
 	qtd = list_entry(qh->qtd_list.next, dwc_otg_qtd_t, qtd_list_entry);
 
 	if (qtd->complete_split) {
@@ -623,8 +626,9 @@ static void deactivate_qh(dwc_otg_hcd_t *hcd,
 
 	qh->channel = NULL;
 	qh->qtd_in_process = NULL;
-	spin_unlock(&hcd->lock);
+
 	dwc_otg_hcd_qh_deactivate(hcd, qh, continue_split);
+	SPIN_UNLOCK_IRQRESTORE(&hcd->lock, flags);
 }
 
 /**
@@ -764,10 +768,18 @@ static void release_channel(dwc_otg_hcd_t *hcd,
 	dwc_otg_hc_cleanup(hcd->core_if, hc);
 	list_add_tail(&hc->hc_list_entry, &hcd->free_hc_list);
 
+	if (!hc->halt_on_queue && !hc->halt_pending && hc->qh->nak_frame != 0xffff)
+		hcd->nakking_channels--;
+
 	switch (hc->ep_type) {
 	case DWC_OTG_EP_TYPE_CONTROL:
 	case DWC_OTG_EP_TYPE_BULK:
 		hcd->non_periodic_channels--;
+
+		/* This condition has once been observed, but the cause
+		 * was never determined. Check for it here, to collect
+		 * debug data if it occurs again. */
+		WARN_ON_ONCE(hcd->non_periodic_channels < 0);
 		break;
 
 	default:
@@ -779,6 +791,9 @@ static void release_channel(dwc_otg_hcd_t *hcd,
 		break;
 	}
 
+	if (halt_status != DWC_OTG_HC_XFER_NAK)
+		hc->qh->nak_frame = 0xffff;
+
 	/* Try to queue more transfers now that there's a free channel. */
 	tr_type = dwc_otg_hcd_select_transactions(hcd);
 	if (tr_type != DWC_OTG_TRANSACTION_NONE) {
@@ -807,7 +822,7 @@ static void halt_channel(dwc_otg_hcd_t *hcd,
 	}
 
 	/* Slave mode processing... */
-	dwc_otg_hc_halt(hcd->core_if, hc, halt_status);
+	dwc_otg_hc_halt(hcd, hc, halt_status);
 
 	if (hc->halt_on_queue) {
 		gintmsk_data_t gintmsk = {.d32 = 0};
@@ -1085,6 +1100,7 @@ static void update_urb_state_xfer_intr(dwc_hc_t *hc,
 		DWC_DEBUGPL(DBG_HCDV, "  hctsiz.pktcnt %d\n", hctsiz.b.pktcnt);
 		DWC_DEBUGPL(DBG_HCDV, "  hc->max_packet %d\n", hc->max_packet);
 		DWC_DEBUGPL(DBG_HCDV, "  bytes_transferred %d\n", bytes_transferred);
+		DWC_DEBUGPL(DBG_HCDV, "  urb %p\n", urb);
 		DWC_DEBUGPL(DBG_HCDV, "  urb->actual_length %d\n", urb->actual_length);
 		DWC_DEBUGPL(DBG_HCDV, "  urb->transfer_buffer_length %d\n",
 			    urb->transfer_buffer_length);
@@ -1103,6 +1119,23 @@ static int32_t handle_hc_nak_intr(dwc_otg_hcd_t *hcd,
 {
 	DWC_DEBUGPL(DBG_HCD, "--Host Channel %d Interrupt: "
 		    "NAK Received--\n", hc->hc_num);
+	/*
+	* When we get bulk NAKs then remember this so we holdoff on this qh until
+	* the beginning of the next frame
+	*/
+	switch (usb_pipetype(qtd->urb->pipe)) {
+		case PIPE_BULK:
+			/* xfer_started can be 0 when a halted interrupt
+			 * occurs with the nak flag set, then first the
+			 * halted handler runs and then this nak
+			 * handler. In this case, also don't update
+			 * nak_frame, since the qh might already be
+			 * assigned to another host channel. */
+			if (!hc->halt_on_queue && !hc->halt_pending && hc->xfer_started && hc->qh->nak_frame == 0xffff)
+				hcd->nakking_channels++;
+			if (hc->xfer_started)
+				hc->qh->nak_frame = dwc_otg_hcd_get_frame_number(dwc_otg_hcd_to_hcd(hcd));
+	}
 
 	/*
 	 * Handle NAK for IN/OUT SSPLIT/CSPLIT transfers, bulk, control, and
@@ -1410,7 +1443,7 @@ static int32_t handle_hc_ahberr_intr(dwc_otg_hcd_t *hcd,
 	 * Force a channel halt. Don't call halt_channel because that won't
 	 * write to the HCCHARn register in DMA mode to force the halt.
 	 */
-	dwc_otg_hc_halt(hcd->core_if, hc, DWC_OTG_HC_XFER_AHB_ERR);
+	dwc_otg_hc_halt(hcd, hc, DWC_OTG_HC_XFER_AHB_ERR);
 
 	disable_hc_int(hc_regs, ahberr);
 	return 1;
@@ -1515,13 +1548,28 @@ static int32_t handle_hc_datatglerr_intr(dwc_otg_hcd_t *hcd,
 					 dwc_otg_qtd_t *qtd)
 {
 	DWC_DEBUGPL(DBG_HCD, "--Host Channel %d Interrupt: "
-		    "Data Toggle Error--\n", hc->hc_num);
+		"Data Toggle Error on %s transfer--\n",
+		hc->hc_num, (hc->ep_is_in ? "IN" : "OUT"));
 
-	if (hc->ep_is_in) {
+	/* Data toggles on split transactions cause the hc to halt.
+	 * restart transfer */
+	if (hc->qh->do_split) {
+		qtd->error_count++;
+		save_data_toggle(hc, hc_regs, qtd);
+		update_urb_state_xfer_intr(hc, hc_regs,
+			qtd->urb, qtd, DWC_OTG_HC_XFER_XACT_ERR);
+		halt_channel(hcd, hc, qtd, DWC_OTG_HC_XFER_XACT_ERR);
+	} else if (hc->ep_is_in) {
+		/* An unmasked data toggle error on a non-split DMA transaction 
+is
+		 * for the sole purpose of resetting error counts. Disable other
+		 * interrupts unmasked for the same reason.
+		 */
+		if (hcd->core_if->dma_enable) {
+			disable_hc_int(hc_regs, ack);
+			disable_hc_int(hc_regs, nak);
+		}
 		qtd->error_count = 0;
-	} else {
-		DWC_ERROR("Data Toggle Error on OUT transfer,"
-			  "channel %d\n", hc->hc_num);
 	}
 
 	disable_hc_int(hc_regs, datatglerr);
@@ -1583,6 +1631,8 @@ static inline int halt_status_ok(dwc_otg_hcd_t *hcd,
 			 "hcchar 0x%08x, trying to halt again\n",
 			 __func__, hcchar.d32);
 		clear_hc_int(hc_regs, chhltd);
+		if (hc->halt_pending && !hc->halt_on_queue && hc->qh->nak_frame != 0xffff)
+			hcd->nakking_channels++;
 		hc->halt_pending = 0;
 		halt_channel(hcd, hc, qtd, hc->halt_status);
 		return 0;
@@ -1612,13 +1662,46 @@ static void handle_hc_chhltd_intr_dma(dwc_otg_hcd_t *hcd,
 		if (hc->speed == DWC_OTG_EP_SPEED_HIGH && !hc->ep_is_in &&
 		    (hc->ep_type == DWC_OTG_EP_TYPE_CONTROL ||
 		     hc->ep_type == DWC_OTG_EP_TYPE_BULK)) {
-			DWC_DEBUGPL(DBG_HCD, "OUT NAK enhancement enabled\n");
+			DWC_DEBUGPL(DBG_HCD_FLOOD, "OUT NAK enhancement enabled\n");
 			out_nak_enh = 1;
 		} else {
-			DWC_DEBUGPL(DBG_HCD, "OUT NAK enhancement disabled, not HS Ctrl/Bulk OUT EP\n");
+			DWC_DEBUGPL(DBG_HCD_FLOOD, "OUT NAK enhancement disabled, not HS Ctrl/Bulk OUT EP\n");
 		}
 	} else {
-		DWC_DEBUGPL(DBG_HCD, "OUT NAK enhancement disabled, no core support\n");
+		DWC_DEBUGPL(DBG_HCD_FLOOD, "OUT NAK enhancement disabled, no core support\n");
+	}
+
+	if (hc->halt_status == DWC_OTG_HC_XFER_NAK) {
+		/* The channel was nakking and halted to free up the
+		 * channel for another transfer. If this channel has
+		 * already received data, we need to skip that amount on
+		 * the next try.
+		 */
+		update_urb_state_xfer_intr(hc, hc_regs, qtd->urb,
+						   qtd, DWC_OTG_HC_XFER_NAK);
+
+		save_data_toggle(hc, hc_regs, qtd);
+
+		/* It turns out that sometimes a channel is halted just
+		 * as it receives its last packet. This causes the
+		 * to trigger a channel halted interrupt without a
+		 * transfer complete flag, even though the transfer is
+		 * actually complete. If we don't handle that here, the
+		 * qtd will be resubmitted and since bulk in can't have
+		 * empty packets, this will cause one full packet of
+		 * "extra" data to be transfered. So we check here to
+		 * see if the transfer is complete and handle that
+		 * accordingly.
+		 */
+		if (usb_pipebulk(qtd->urb->pipe) &&
+		    usb_pipein(qtd->urb->pipe) &&
+		    qtd->urb->actual_length == qtd->urb->transfer_buffer_length) {
+			dwc_otg_hcd_complete_urb(hcd, qtd->urb, 0);
+			complete_non_periodic_xfer(hcd, hc, hc_regs, qtd, DWC_OTG_HC_XFER_URB_COMPLETE);
+		} else {
+			release_channel(hcd, hc, qtd, hc->halt_status);
+		}
+		return;
 	}
 
 	if (hc->halt_status == DWC_OTG_HC_XFER_URB_DEQUEUE ||
@@ -1666,6 +1749,8 @@ static void handle_hc_chhltd_intr_dma(dwc_otg_hcd_t *hcd,
 		 * that started with a PING. The xacterr takes precedence.
 		 */
 		handle_hc_xacterr_intr(hcd, hc, hc_regs, qtd);
+	} else if (hcint.b.datatglerr) {
+		handle_hc_datatglerr_intr(hcd, hc, hc_regs, qtd);
 	} else if (!out_nak_enh) {
 		if (hcint.b.nyet) {
 			/*
@@ -1767,6 +1852,10 @@ int32_t dwc_otg_hcd_handle_hc_n_intr(dwc_otg_hcd_t *dwc_otg_hcd, uint32_t num)
 	DWC_DEBUGPL(DBG_HCDV, "--Host Channel Interrupt--, Channel %d\n", num);
 
 	hc = dwc_otg_hcd->hc_ptr_array[num];
+
+	check_nakking(dwc_otg_hcd, __FUNCTION__,  "start");
+
+
 	hc_regs = dwc_otg_hcd->core_if->host_if->hc_regs[num];
 	qtd = list_entry(hc->qh->qtd_list.next, dwc_otg_qtd_t, qtd_list_entry);
 
@@ -1774,6 +1863,7 @@ int32_t dwc_otg_hcd_handle_hc_n_intr(dwc_otg_hcd_t *dwc_otg_hcd, uint32_t num)
 	hcintmsk.d32 = dwc_read_reg32(&hc_regs->hcintmsk);
 	DWC_DEBUGPL(DBG_HCDV, "  hcint 0x%08x, hcintmsk 0x%08x, hcint&hcintmsk 0x%08x\n",
 		    hcint.d32, hcintmsk.d32, (hcint.d32 & hcintmsk.d32));
+
 	hcint.d32 = hcint.d32 & hcintmsk.d32;
 
 	if (!dwc_otg_hcd->core_if->dma_enable) {
@@ -1803,7 +1893,7 @@ int32_t dwc_otg_hcd_handle_hc_n_intr(dwc_otg_hcd_t *dwc_otg_hcd, uint32_t num)
 	if (hcint.b.nak) {
 		retval |= handle_hc_nak_intr(dwc_otg_hcd, hc, hc_regs, qtd);
 	}
-	if (hcint.b.ack) {
+	if (hcint.b.ack && !hcint.b.chhltd) {
 		retval |= handle_hc_ack_intr(dwc_otg_hcd, hc, hc_regs, qtd);
 	}
 	if (hcint.b.nyet) {
@@ -1821,6 +1911,11 @@ int32_t dwc_otg_hcd_handle_hc_n_intr(dwc_otg_hcd_t *dwc_otg_hcd, uint32_t num)
 	if (hcint.b.datatglerr) {
 		retval |= handle_hc_datatglerr_intr(dwc_otg_hcd, hc, hc_regs, qtd);
 	}
+	if (check_nakking(dwc_otg_hcd, __FUNCTION__,  "end")) {
+		DWC_WARN("--Host Channel Interrupt--, Channel %d\n", num);
+		DWC_WARN("  hcint 0x%08x, hcintmsk 0x%08x, hcint&hcintmsk 0x%08x\n",
+		    hcint.d32, hcintmsk.d32, (hcint.d32 & hcintmsk.d32));
+	}
 
 	return retval;
 }
diff --git a/target/linux/cns3xxx/files/drivers/usb/dwc/otg_hcd_queue.c b/target/linux/cns3xxx/files/drivers/usb/dwc/otg_hcd_queue.c
index 7395d1dcfc..6e7b53c392 100644
--- a/target/linux/cns3xxx/files/drivers/usb/dwc/otg_hcd_queue.c
+++ b/target/linux/cns3xxx/files/drivers/usb/dwc/otg_hcd_queue.c
@@ -211,6 +211,8 @@ void dwc_otg_hcd_qh_init(dwc_otg_hcd_t *hcd, dwc_otg_qh_t *qh, struct urb *urb)
 		    usb_pipeendpoint(urb->pipe),
 		    usb_pipein(urb->pipe) == USB_DIR_IN ? "IN" : "OUT");
 
+	qh->nak_frame = 0xffff;
+
 	switch(urb->dev->speed) {
 	case USB_SPEED_LOW:
 		speed = "low";
@@ -453,7 +455,26 @@ static int schedule_periodic(dwc_otg_hcd_t *hcd, dwc_otg_qh_t *qh)
 	int status;
 	struct usb_bus *bus = hcd_to_bus(dwc_otg_hcd_to_hcd(hcd));
 	int frame;
-
+	int num_channels;
+
+	num_channels = hcd->core_if->core_params->host_channels;
+
+	if ((hcd->periodic_channels < num_channels - 1)) {
+	  if (hcd->periodic_channels + hcd->nakking_channels >= num_channels) {
+	    /* All non-periodic channels are nakking? Halt
+	     * one to make room (as long as there is at
+	     * least one channel for non-periodic transfers,
+	     * all the blocking non-periodics can time-share
+	     * that one channel. */
+	    dwc_hc_t *hc = dwc_otg_halt_nakking_channel(hcd);
+	    if (hc)
+	      DWC_DEBUGPL(DBG_HCD, "Out of Host Channels for periodic transfer - Halting channel %d (dev %d ep%d%s)\n", hc->hc_num, hc->dev_addr, hc->ep_num, (hc->ep_is_in ? "in" : "out"));
+	  }
+	  /* It could be that all channels are currently occupied,
+	   * but in that case one will be freed up soon (either
+	   * because it completed or because it was forced to halt
+	   * above). */
+	}
 	status = find_uframe(hcd, qh);
 	frame = -1;
 	if (status == 0) {
@@ -483,6 +504,8 @@ static int schedule_periodic(dwc_otg_hcd_t *hcd, dwc_otg_qh_t *qh)
 	/* Always start in the inactive schedule. */
 	list_add_tail(&qh->qh_list_entry, &hcd->periodic_sched_inactive);
 
+	hcd->periodic_channels++;
+
 	/* Update claimed usecs per (micro)frame. */
 	hcd->periodic_usecs += qh->usecs;
 
@@ -553,6 +576,9 @@ static void deschedule_periodic(dwc_otg_hcd_t *hcd, dwc_otg_qh_t *qh)
 	int i;
 
 	list_del_init(&qh->qh_list_entry);
+
+	hcd->periodic_channels--;
+
 	/* Update claimed usecs per (micro)frame. */
 	hcd->periodic_usecs -= qh->usecs;
 	for (i = 0; i < 8; i++) {
@@ -628,9 +654,6 @@ void dwc_otg_hcd_qh_remove (dwc_otg_hcd_t *hcd, dwc_otg_qh_t *qh)
  */
 void dwc_otg_hcd_qh_deactivate(dwc_otg_hcd_t *hcd, dwc_otg_qh_t *qh, int sched_next_periodic_split)
 {
-	unsigned long flags;
-	SPIN_LOCK_IRQSAVE(&hcd->lock, flags);
-
 	if (dwc_qh_is_non_per(qh)) {
 		dwc_otg_hcd_qh_remove(hcd, qh);
 		if (!list_empty(&qh->qtd_list)) {
@@ -690,8 +713,6 @@ void dwc_otg_hcd_qh_deactivate(dwc_otg_hcd_t *hcd, dwc_otg_qh_t *qh, int sched_n
 			}
 		}
 	}
-
-	SPIN_UNLOCK_IRQRESTORE(&hcd->lock, flags);
 }
 
 /**
@@ -759,22 +780,22 @@ int dwc_otg_hcd_qtd_add (dwc_otg_qtd_t *qtd,
 {
 	struct usb_host_endpoint *ep;
 	dwc_otg_qh_t *qh;
-	unsigned long flags;
 	int retval = 0;
 
 	struct urb *urb = qtd->urb;
 
-	SPIN_LOCK_IRQSAVE(&dwc_otg_hcd->lock, flags);
-
 	/*
 	 * Get the QH which holds the QTD-list to insert to. Create QH if it
 	 * doesn't exist.
 	 */
+	usb_hcd_link_urb_to_ep(dwc_otg_hcd_to_hcd(dwc_otg_hcd), urb);
 	ep = dwc_urb_to_endpoint(urb);
 	qh = (dwc_otg_qh_t *)ep->hcpriv;
 	if (qh == NULL) {
 		qh = dwc_otg_hcd_qh_create (dwc_otg_hcd, urb);
 		if (qh == NULL) {
+			usb_hcd_unlink_urb_from_ep(dwc_otg_hcd_to_hcd(dwc_otg_hcd), urb);
+			retval = -ENOMEM;
 			goto done;
 		}
 		ep->hcpriv = qh;
@@ -783,11 +804,11 @@ int dwc_otg_hcd_qtd_add (dwc_otg_qtd_t *qtd,
 	retval = dwc_otg_hcd_qh_add(dwc_otg_hcd, qh);
 	if (retval == 0) {
 		list_add_tail(&qtd->qtd_list_entry, &qh->qtd_list);
+	} else {
+		usb_hcd_unlink_urb_from_ep(dwc_otg_hcd_to_hcd(dwc_otg_hcd), urb);
 	}
 
  done:
-	SPIN_UNLOCK_IRQRESTORE(&dwc_otg_hcd->lock, flags);
-
 	return retval;
 }
 
diff --git a/target/linux/cns3xxx/files/drivers/usb/dwc/otg_plat.h b/target/linux/cns3xxx/files/drivers/usb/dwc/otg_plat.h
index 1744a1fbc8..7b9ae57f59 100644
--- a/target/linux/cns3xxx/files/drivers/usb/dwc/otg_plat.h
+++ b/target/linux/cns3xxx/files/drivers/usb/dwc/otg_plat.h
@@ -202,6 +202,7 @@ static inline uint32_t SET_DEBUG_LEVEL( const uint32_t new )
 /** When debug level has the DBG_HCD_URB bit set, display enqueued URBs in host
  *  mode. */
 #define DBG_HCD_URB	(0x800)
+#define DBG_HCD_FLOOD (0x1)
 
 /** When debug level has any bit set, display debug messages */
 #define DBG_ANY		(0xFF)