usb: dwc2: Change ISOC DDMA flow

Changed existing two descriptor-chain flow to one chain.

In two-chain implementation BNA interrupt used for switching between
two chains. BNA interrupt asserted because of returning to
beginning of the chain based on L-bit of last descriptor.

Because of that we lose packets. This issue resolved by using one
desc-chain.

Removed all staff related to two desc-chain flow from
DDMA ISOC related functions.

Removed request length checking from dwc2_gadget_fill_isoc_desc()
function. Request length checking added to dwc2_hsotg_ep_queue()
function. If request length greater than descriptor limits then
request not added to queue. Additional checking done for High
Bandwidth ISOC OUT's which not supported by driver. In
dwc2_gadget_fill_isoc_desc() function also checked desc-chain
status (full or not) to avoid of reusing not yet processed
descriptors.

In dwc2_gadget_start_isoc_ddma() function creation of desc-chain
always started from descriptor 0. Before filling descriptors, they
were initialized by HOST BUSY status.

In dwc2_gadget_complete_isoc_request_ddma() added checking for
desc-chain rollover. Also added checking completion status.
Request completed successfully if DEV_DMA_STS is DEV_DMA_STS_SUCC,
otherwise complete with actual=0. For systems with high IRQ latency
added pointer compl_desc to next descriptor to be completed by
XferCompl interrupt. This pointer replace descriptor index calculation
based on DxEPDMA register. On descriptor completion interrupt
processing all descriptors starting from compl_desc till descriptor
which Buffer Status field not equal DMA_DONE status.

Actually removed dwc2_gadget_start_next_isoc_ddma() function because
now driver use only one desc-chain and instead that function added
dwc2_gadget_handle_isoc_bna() function for handling BNA interrupts.

Handling BNA interrupt done by flushing TxFIFOs for OUT EPs,
completing request with actual=0 and resetting desc-chain number and
target frame to initial values for restarting transfers.

On handling NAK request completed with actual=0. Incremented target
frame to allow fill desc chain and start transfers.
In DDMA mode avoided of frame number incrementing, because tracking
of frame number performed in dwc2_gadget_fill_isoc_desc() function.

When core assert XferCompl along with BNA, we should ignore XferCompl
in dwc2_hsotg_epint() function.

On BNA interrupt replaced dwc2_gadget_start_next_isoc_ddma() by above
mentioned BNA handler.

In dwc2_hsotg_ep_enable() function added sanity check of bInterval
for ISOC IN in DDMA mode, because HW doesn't supported EP's with
bInterval more than 10 and check for mc for ISOC OUT transfers,
because core doesn't support high bandwidth transfers.

Signed-off-by: Minas Harutyunyan <hminas@synopsys.com>
Signed-off-by: Felipe Balbi <felipe.balbi@linux.intel.com>

2 files changed, 139 insertions, 144 deletions

diff --git a/drivers/usb/dwc2/core.h b/drivers/usb/dwc2/core.h
index d83be5651f87..274bf0a83ae4 100644
--- a/drivers/usb/dwc2/core.h
+++ b/drivers/usb/dwc2/core.h
@@ -178,8 +178,8 @@ struct dwc2_hsotg_req;
  * @desc_list_dma: The DMA address of descriptor chain currently in use.
  * @desc_list: Pointer to descriptor DMA chain head currently in use.
  * @desc_count: Count of entries within the DMA descriptor chain of EP.
- * @isoc_chain_num: Number of ISOC chain currently in use - either 0 or 1.
  * @next_desc: index of next free descriptor in the ISOC chain under SW control.
+ * @compl_desc: index of next descriptor to be completed by xFerComplete
  * @total_data: The total number of data bytes done.
  * @fifo_size: The size of the FIFO (for periodic IN endpoints)
  * @fifo_load: The amount of data loaded into the FIFO (periodic IN)
@@ -231,8 +231,8 @@ struct dwc2_hsotg_ep {
 	struct dwc2_dma_desc	*desc_list;
 	u8			desc_count;
 
-	unsigned char		isoc_chain_num;
 	unsigned int		next_desc;
+	unsigned int		compl_desc;
 
 	char                    name[10];
 };
diff --git a/drivers/usb/dwc2/gadget.c b/drivers/usb/dwc2/gadget.c
index 6c32bf26e48e..ec88f7e23f31 100644
--- a/drivers/usb/dwc2/gadget.c
+++ b/drivers/usb/dwc2/gadget.c
@@ -793,9 +793,7 @@ static void dwc2_gadget_config_nonisoc_xfer_ddma(struct dwc2_hsotg_ep *hs_ep,
  * @dma_buff: usb requests dma buffer.
  * @len: usb request transfer length.
  *
- * Finds out index of first free entry either in the bottom or up half of
- * descriptor chain depend on which is under SW control and not processed
- * by HW. Then fills that descriptor with the data of the arrived usb request,
+ * Fills next free descriptor with the data of the arrived usb request,
  * frame info, sets Last and IOC bits increments next_desc. If filled
  * descriptor is not the first one, removes L bit from the previous descriptor
  * status.
@@ -810,34 +808,17 @@ static int dwc2_gadget_fill_isoc_desc(struct dwc2_hsotg_ep *hs_ep,
 	u32 mask = 0;
 
 	maxsize = dwc2_gadget_get_desc_params(hs_ep, &mask);
-	if (len > maxsize) {
-		dev_err(hsotg->dev, "wrong len %d\n", len);
-		return -EINVAL;
-	}
 
-	/*
-	 * If SW has already filled half of chain, then return and wait for
-	 * the other chain to be processed by HW.
-	 */
-	if (hs_ep->next_desc == MAX_DMA_DESC_NUM_GENERIC / 2)
-		return -EBUSY;
-
-	/* Increment frame number by interval for IN */
-	if (hs_ep->dir_in)
-		dwc2_gadget_incr_frame_num(hs_ep);
-
-	index = (MAX_DMA_DESC_NUM_GENERIC / 2) * hs_ep->isoc_chain_num +
-		 hs_ep->next_desc;
+	index = hs_ep->next_desc;
+	desc = &hs_ep->desc_list[index];
 
-	/* Sanity check of calculated index */
-	if ((hs_ep->isoc_chain_num && index > MAX_DMA_DESC_NUM_GENERIC) ||
-	    (!hs_ep->isoc_chain_num && index > MAX_DMA_DESC_NUM_GENERIC / 2)) {
-		dev_err(hsotg->dev, "wrong index %d for iso chain\n", index);
-		return -EINVAL;
+	/* Check if descriptor chain full */
+	if ((desc->status >> DEV_DMA_BUFF_STS_SHIFT) ==
+	    DEV_DMA_BUFF_STS_HREADY) {
+		dev_dbg(hsotg->dev, "%s: desc chain full\n", __func__);
+		return 1;
 	}
 
-	desc = &hs_ep->desc_list[index];
-
 	/* Clear L bit of previous desc if more than one entries in the chain */
 	if (hs_ep->next_desc)
 		hs_ep->desc_list[index - 1].status &= ~DEV_DMA_L;
@@ -865,8 +846,14 @@ static int dwc2_gadget_fill_isoc_desc(struct dwc2_hsotg_ep *hs_ep,
 	desc->status &= ~DEV_DMA_BUFF_STS_MASK;
 	desc->status |= (DEV_DMA_BUFF_STS_HREADY << DEV_DMA_BUFF_STS_SHIFT);
 
+	/* Increment frame number by interval for IN */
+	if (hs_ep->dir_in)
+		dwc2_gadget_incr_frame_num(hs_ep);
+
 	/* Update index of last configured entry in the chain */
 	hs_ep->next_desc++;
+	if (hs_ep->next_desc >= MAX_DMA_DESC_NUM_GENERIC)
+		hs_ep->next_desc = 0;
 
 	return 0;
 }
@@ -875,11 +862,8 @@ static int dwc2_gadget_fill_isoc_desc(struct dwc2_hsotg_ep *hs_ep,
  * dwc2_gadget_start_isoc_ddma - start isochronous transfer in DDMA
  * @hs_ep: The isochronous endpoint.
  *
- * Prepare first descriptor chain for isochronous endpoints. Afterwards
+ * Prepare descriptor chain for isochronous endpoints. Afterwards
  * write DMA address to HW and enable the endpoint.
- *
- * Switch between descriptor chains via isoc_chain_num to give SW opportunity
- * to prepare second descriptor chain while first one is being processed by HW.
  */
 static void dwc2_gadget_start_isoc_ddma(struct dwc2_hsotg_ep *hs_ep)
 {
@@ -887,24 +871,34 @@ static void dwc2_gadget_start_isoc_ddma(struct dwc2_hsotg_ep *hs_ep)
 	struct dwc2_hsotg_req *hs_req, *treq;
 	int index = hs_ep->index;
 	int ret;
+	int i;
 	u32 dma_reg;
 	u32 depctl;
 	u32 ctrl;
+	struct dwc2_dma_desc *desc;
 
 	if (list_empty(&hs_ep->queue)) {
 		dev_dbg(hsotg->dev, "%s: No requests in queue\n", __func__);
 		return;
 	}
 
+	/* Initialize descriptor chain by Host Busy status */
+	for (i = 0; i < MAX_DMA_DESC_NUM_GENERIC; i++) {
+		desc = &hs_ep->desc_list[i];
+		desc->status = 0;
+		desc->status |= (DEV_DMA_BUFF_STS_HBUSY
+				    << DEV_DMA_BUFF_STS_SHIFT);
+	}
+
+	hs_ep->next_desc = 0;
 	list_for_each_entry_safe(hs_req, treq, &hs_ep->queue, queue) {
 		ret = dwc2_gadget_fill_isoc_desc(hs_ep, hs_req->req.dma,
 						 hs_req->req.length);
-		if (ret) {
-			dev_dbg(hsotg->dev, "%s: desc chain full\n", __func__);
+		if (ret)
 			break;
-		}
 	}
 
+	hs_ep->compl_desc = 0;
 	depctl = hs_ep->dir_in ? DIEPCTL(index) : DOEPCTL(index);
 	dma_reg = hs_ep->dir_in ? DIEPDMA(index) : DOEPDMA(index);
 
@@ -914,10 +908,6 @@ static void dwc2_gadget_start_isoc_ddma(struct dwc2_hsotg_ep *hs_ep)
 	ctrl = dwc2_readl(hsotg->regs + depctl);
 	ctrl |= DXEPCTL_EPENA | DXEPCTL_CNAK;
 	dwc2_writel(ctrl, hsotg->regs + depctl);
-
-	/* Switch ISOC descriptor chain number being processed by SW*/
-	hs_ep->isoc_chain_num = (hs_ep->isoc_chain_num ^ 1) & 0x1;
-	hs_ep->next_desc = 0;
 }
 
 /**
@@ -1291,6 +1281,9 @@ static int dwc2_hsotg_ep_queue(struct usb_ep *ep, struct usb_request *req,
 	struct dwc2_hsotg *hs = hs_ep->parent;
 	bool first;
 	int ret;
+	u32 maxsize = 0;
+	u32 mask = 0;
+
 
 	dev_dbg(hs->dev, "%s: req %p: %d@%p, noi=%d, zero=%d, snok=%d\n",
 		ep->name, req, req->length, req->buf, req->no_interrupt,
@@ -1308,6 +1301,24 @@ static int dwc2_hsotg_ep_queue(struct usb_ep *ep, struct usb_request *req,
 	req->actual = 0;
 	req->status = -EINPROGRESS;
 
+	/* In DDMA mode for ISOC's don't queue request if length greater
+	 * than descriptor limits.
+	 */
+	if (using_desc_dma(hs) && hs_ep->isochronous) {
+		maxsize = dwc2_gadget_get_desc_params(hs_ep, &mask);
+		if (hs_ep->dir_in && req->length > maxsize) {
+			dev_err(hs->dev, "wrong length %d (maxsize=%d)\n",
+				req->length, maxsize);
+			return -EINVAL;
+		}
+
+		if (!hs_ep->dir_in && req->length > hs_ep->ep.maxpacket) {
+			dev_err(hs->dev, "ISOC OUT: wrong length %d (mps=%d)\n",
+				req->length, hs_ep->ep.maxpacket);
+			return -EINVAL;
+		}
+	}
+
 	ret = dwc2_hsotg_handle_unaligned_buf_start(hs, hs_ep, hs_req);
 	if (ret)
 		return ret;
@@ -1330,17 +1341,15 @@ static int dwc2_hsotg_ep_queue(struct usb_ep *ep, struct usb_request *req,
 
 	/*
 	 * Handle DDMA isochronous transfers separately - just add new entry
-	 * to the half of descriptor chain that is not processed by HW.
+	 * to the descriptor chain.
 	 * Transfer will be started once SW gets either one of NAK or
 	 * OutTknEpDis interrupts.
 	 */
-	if (using_desc_dma(hs) && hs_ep->isochronous &&
-	    hs_ep->target_frame != TARGET_FRAME_INITIAL) {
-		ret = dwc2_gadget_fill_isoc_desc(hs_ep, hs_req->req.dma,
-						 hs_req->req.length);
-		if (ret)
-			dev_dbg(hs->dev, "%s: ISO desc chain full\n", __func__);
-
+	if (using_desc_dma(hs) && hs_ep->isochronous) {
+		if (hs_ep->target_frame != TARGET_FRAME_INITIAL) {
+			dwc2_gadget_fill_isoc_desc(hs_ep, hs_req->req.dma,
+						   hs_req->req.length);
+		}
 		return 0;
 	}
 
@@ -2011,108 +2020,75 @@ static void dwc2_hsotg_complete_request(struct dwc2_hsotg *hsotg,
  * @hs_ep: The endpoint the request was on.
  *
  * Get first request from the ep queue, determine descriptor on which complete
- * happened. SW based on isoc_chain_num discovers which half of the descriptor
- * chain is currently in use by HW, adjusts dma_address and calculates index
- * of completed descriptor based on the value of DEPDMA register. Update actual
- * length of request, giveback to gadget.
+ * happened. SW discovers which descriptor currently in use by HW, adjusts
+ * dma_address and calculates index of completed descriptor based on the value
+ * of DEPDMA register. Update actual length of request, giveback to gadget.
  */
 static void dwc2_gadget_complete_isoc_request_ddma(struct dwc2_hsotg_ep *hs_ep)
 {
 	struct dwc2_hsotg *hsotg = hs_ep->parent;
 	struct dwc2_hsotg_req *hs_req;
 	struct usb_request *ureq;
-	int index;
-	dma_addr_t dma_addr;
-	u32 dma_reg;
-	u32 depdma;
 	u32 desc_sts;
 	u32 mask;
 
-	hs_req = get_ep_head(hs_ep);
-	if (!hs_req) {
-		dev_warn(hsotg->dev, "%s: ISOC EP queue empty\n", __func__);
-		return;
-	}
-	ureq = &hs_req->req;
+	desc_sts = hs_ep->desc_list[hs_ep->compl_desc].status;
 
-	dma_addr = hs_ep->desc_list_dma;
+	/* Process only descriptors with buffer status set to DMA done */
+	while ((desc_sts & DEV_DMA_BUFF_STS_MASK) >>
+		DEV_DMA_BUFF_STS_SHIFT == DEV_DMA_BUFF_STS_DMADONE) {
 
-	/*
-	 * If lower half of  descriptor chain is currently use by SW,
-	 * that means higher half is being processed by HW, so shift
-	 * DMA address to higher half of descriptor chain.
-	 */
-	if (!hs_ep->isoc_chain_num)
-		dma_addr += sizeof(struct dwc2_dma_desc) *
-			    (MAX_DMA_DESC_NUM_GENERIC / 2);
-
-	dma_reg = hs_ep->dir_in ? DIEPDMA(hs_ep->index) : DOEPDMA(hs_ep->index);
-	depdma = dwc2_readl(hsotg->regs + dma_reg);
-
-	index = (depdma - dma_addr) / sizeof(struct dwc2_dma_desc) - 1;
-	desc_sts = hs_ep->desc_list[index].status;
-
-	mask = hs_ep->dir_in ? DEV_DMA_ISOC_TX_NBYTES_MASK :
-	       DEV_DMA_ISOC_RX_NBYTES_MASK;
-	ureq->actual = ureq->length -
-		       ((desc_sts & mask) >> DEV_DMA_ISOC_NBYTES_SHIFT);
+		hs_req = get_ep_head(hs_ep);
+		if (!hs_req) {
+			dev_warn(hsotg->dev, "%s: ISOC EP queue empty\n", __func__);
+			return;
+		}
+		ureq = &hs_req->req;
+
+		/* Check completion status */
+		if ((desc_sts & DEV_DMA_STS_MASK) >> DEV_DMA_STS_SHIFT ==
+			DEV_DMA_STS_SUCC) {
+			mask = hs_ep->dir_in ? DEV_DMA_ISOC_TX_NBYTES_MASK :
+				DEV_DMA_ISOC_RX_NBYTES_MASK;
+			ureq->actual = ureq->length - ((desc_sts & mask) >>
+				DEV_DMA_ISOC_NBYTES_SHIFT);
+
+			/* Adjust actual len for ISOC Out if len is
+			 * not align of 4
+			 */
+			if (!hs_ep->dir_in && ureq->length & 0x3)
+				ureq->actual += 4 - (ureq->length & 0x3);
+		}
 
-	/* Adjust actual length for ISOC Out if length is not align of 4 */
-	if (!hs_ep->dir_in && ureq->length & 0x3)
-		ureq->actual += 4 - (ureq->length & 0x3);
+		dwc2_hsotg_complete_request(hsotg, hs_ep, hs_req, 0);
 
-	dwc2_hsotg_complete_request(hsotg, hs_ep, hs_req, 0);
+		hs_ep->compl_desc++;
+		if (hs_ep->compl_desc > (MAX_DMA_DESC_NUM_GENERIC - 1))
+			hs_ep->compl_desc = 0;
+		desc_sts = hs_ep->desc_list[hs_ep->compl_desc].status;
+	}
 }
 
 /*
- * dwc2_gadget_start_next_isoc_ddma - start next isoc request, if any.
- * @hs_ep: The isochronous endpoint to be re-enabled.
+ * dwc2_gadget_handle_isoc_bna - handle BNA interrupt for ISOC.
+ * @hs_ep: The isochronous endpoint.
  *
- * If ep has been disabled due to last descriptor servicing (IN endpoint) or
- * BNA (OUT endpoint) check the status of other half of descriptor chain that
- * was under SW control till HW was busy and restart the endpoint if needed.
+ * If EP ISOC OUT then need to flush RX FIFO to remove source of BNA
+ * interrupt. Reset target frame and next_desc to allow to start
+ * ISOC's on NAK interrupt for IN direction or on OUTTKNEPDIS
+ * interrupt for OUT direction.
  */
-static void dwc2_gadget_start_next_isoc_ddma(struct dwc2_hsotg_ep *hs_ep)
+static void dwc2_gadget_handle_isoc_bna(struct dwc2_hsotg_ep *hs_ep)
 {
 	struct dwc2_hsotg *hsotg = hs_ep->parent;
-	u32 depctl;
-	u32 dma_reg;
-	u32 ctrl;
-	u32 dma_addr = hs_ep->desc_list_dma;
-	unsigned char index = hs_ep->index;
-
-	dma_reg = hs_ep->dir_in ? DIEPDMA(index) : DOEPDMA(index);
-	depctl = hs_ep->dir_in ? DIEPCTL(index) : DOEPCTL(index);
 
-	ctrl = dwc2_readl(hsotg->regs + depctl);
-
-	/*
-	 * EP was disabled if HW has processed last descriptor or BNA was set.
-	 * So restart ep if SW has prepared new descriptor chain in ep_queue
-	 * routine while HW was busy.
-	 */
-	if (!(ctrl & DXEPCTL_EPENA)) {
-		if (!hs_ep->next_desc) {
-			dev_dbg(hsotg->dev, "%s: No more ISOC requests\n",
-				__func__);
-			return;
-		}
+	if (!hs_ep->dir_in)
+		dwc2_flush_rx_fifo(hsotg);
+	dwc2_hsotg_complete_request(hsotg, hs_ep, get_ep_head(hs_ep), 0);
 
-		dma_addr += sizeof(struct dwc2_dma_desc) *
-			    (MAX_DMA_DESC_NUM_GENERIC / 2) *
-			    hs_ep->isoc_chain_num;
-		dwc2_writel(dma_addr, hsotg->regs + dma_reg);
-
-		ctrl |= DXEPCTL_EPENA | DXEPCTL_CNAK;
-		dwc2_writel(ctrl, hsotg->regs + depctl);
-
-		/* Switch ISOC descriptor chain number being processed by SW*/
-		hs_ep->isoc_chain_num = (hs_ep->isoc_chain_num ^ 1) & 0x1;
-		hs_ep->next_desc = 0;
-
-		dev_dbg(hsotg->dev, "%s: Restarted isochronous endpoint\n",
-			__func__);
-	}
+	hs_ep->target_frame = TARGET_FRAME_INITIAL;
+	hs_ep->next_desc = 0;
+	hs_ep->compl_desc = 0;
 }
 
 /**
@@ -2763,7 +2739,7 @@ static void dwc2_gadget_handle_out_token_ep_disabled(struct dwc2_hsotg_ep *ep)
 	 */
 	tmp = dwc2_hsotg_read_frameno(hsotg);
 
-	dwc2_hsotg_complete_request(hsotg, ep, get_ep_head(ep), -ENODATA);
+	dwc2_hsotg_complete_request(hsotg, ep, get_ep_head(ep), 0);
 
 	if (using_desc_dma(hsotg)) {
 		if (ep->target_frame == TARGET_FRAME_INITIAL) {
@@ -2816,18 +2792,25 @@ static void dwc2_gadget_handle_nak(struct dwc2_hsotg_ep *hs_ep)
 {
 	struct dwc2_hsotg *hsotg = hs_ep->parent;
 	int dir_in = hs_ep->dir_in;
+	u32 tmp;
 
 	if (!dir_in || !hs_ep->isochronous)
 		return;
 
 	if (hs_ep->target_frame == TARGET_FRAME_INITIAL) {
-		hs_ep->target_frame = dwc2_hsotg_read_frameno(hsotg);
 
+		tmp = dwc2_hsotg_read_frameno(hsotg);
 		if (using_desc_dma(hsotg)) {
+			dwc2_hsotg_complete_request(hsotg, hs_ep,
+						    get_ep_head(hs_ep), 0);
+
+			hs_ep->target_frame = tmp;
+			dwc2_gadget_incr_frame_num(hs_ep);
 			dwc2_gadget_start_isoc_ddma(hs_ep);
 			return;
 		}
 
+		hs_ep->target_frame = tmp;
 		if (hs_ep->interval > 1) {
 			u32 ctrl = dwc2_readl(hsotg->regs +
 					      DIEPCTL(hs_ep->index));
@@ -2843,7 +2826,8 @@ static void dwc2_gadget_handle_nak(struct dwc2_hsotg_ep *hs_ep)
 					    get_ep_head(hs_ep), 0);
 	}
 
-	dwc2_gadget_incr_frame_num(hs_ep);
+	if (!using_desc_dma(hsotg))
+		dwc2_gadget_incr_frame_num(hs_ep);
 }
 
 /**
@@ -2901,9 +2885,9 @@ static void dwc2_hsotg_epint(struct dwc2_hsotg *hsotg, unsigned int idx,
 
 		/* In DDMA handle isochronous requests separately */
 		if (using_desc_dma(hsotg) && hs_ep->isochronous) {
-			dwc2_gadget_complete_isoc_request_ddma(hs_ep);
-			/* Try to start next isoc request */
-			dwc2_gadget_start_next_isoc_ddma(hs_ep);
+			/* XferCompl set along with BNA */
+			if (!(ints & DXEPINT_BNAINTR))
+				dwc2_gadget_complete_isoc_request_ddma(hs_ep);
 		} else if (dir_in) {
 			/*
 			 * We get OutDone from the FIFO, so we only
@@ -2978,15 +2962,8 @@ static void dwc2_hsotg_epint(struct dwc2_hsotg *hsotg, unsigned int idx,
 
 	if (ints & DXEPINT_BNAINTR) {
 		dev_dbg(hsotg->dev, "%s: BNA interrupt\n", __func__);
-
-		/*
-		 * Try to start next isoc request, if any.
-		 * Sometimes the endpoint remains enabled after BNA interrupt
-		 * assertion, which is not expected, hence we can enter here
-		 * couple of times.
-		 */
 		if (hs_ep->isochronous)
-			dwc2_gadget_start_next_isoc_ddma(hs_ep);
+			dwc2_gadget_handle_isoc_bna(hs_ep);
 	}
 
 	if (dir_in && !hs_ep->isochronous) {
@@ -3789,6 +3766,7 @@ static int dwc2_hsotg_ep_enable(struct usb_ep *ep,
 	unsigned int dir_in;
 	unsigned int i, val, size;
 	int ret = 0;
+	unsigned char ep_type;
 
 	dev_dbg(hsotg->dev,
 		"%s: ep %s: a 0x%02x, attr 0x%02x, mps 0x%04x, intr %d\n",
@@ -3807,9 +3785,26 @@ static int dwc2_hsotg_ep_enable(struct usb_ep *ep,
 		return -EINVAL;
 	}
 
+	ep_type = desc->bmAttributes & USB_ENDPOINT_XFERTYPE_MASK;
 	mps = usb_endpoint_maxp(desc);
 	mc = usb_endpoint_maxp_mult(desc);
 
+	/* ISOC IN in DDMA supported bInterval up to 10 */
+	if (using_desc_dma(hsotg) && ep_type == USB_ENDPOINT_XFER_ISOC &&
+	    dir_in && desc->bInterval > 10) {
+		dev_err(hsotg->dev,
+			"%s: ISOC IN, DDMA: bInterval>10 not supported!\n", __func__);
+		return -EINVAL;
+	}
+
+	/* High bandwidth ISOC OUT in DDMA not supported */
+	if (using_desc_dma(hsotg) && ep_type == USB_ENDPOINT_XFER_ISOC &&
+	    !dir_in && mc > 1) {
+		dev_err(hsotg->dev,
+			"%s: ISOC OUT, DDMA: HB not supported!\n", __func__);
+		return -EINVAL;
+	}
+
 	/* note, we handle this here instead of dwc2_hsotg_set_ep_maxpacket */
 
 	epctrl_reg = dir_in ? DIEPCTL(index) : DOEPCTL(index);
@@ -3850,15 +3845,15 @@ static int dwc2_hsotg_ep_enable(struct usb_ep *ep,
 	hs_ep->halted = 0;
 	hs_ep->interval = desc->bInterval;
 
-	switch (desc->bmAttributes & USB_ENDPOINT_XFERTYPE_MASK) {
+	switch (ep_type) {
 	case USB_ENDPOINT_XFER_ISOC:
 		epctrl |= DXEPCTL_EPTYPE_ISO;
 		epctrl |= DXEPCTL_SETEVENFR;
 		hs_ep->isochronous = 1;
 		hs_ep->interval = 1 << (desc->bInterval - 1);
 		hs_ep->target_frame = TARGET_FRAME_INITIAL;
-		hs_ep->isoc_chain_num = 0;
 		hs_ep->next_desc = 0;
+		hs_ep->compl_desc = 0;
 		if (dir_in) {
 			hs_ep->periodic = 1;
 			mask = dwc2_readl(hsotg->regs + DIEPMSK);