2 files changed, 32 insertions, 1 deletions

diff --git a/drivers/usb/cdns3/cdnsp-gadget.h b/drivers/usb/cdns3/cdnsp-gadget.h
index dbee6f085277..84887dfea763 100644
--- a/drivers/usb/cdns3/cdnsp-gadget.h
+++ b/drivers/usb/cdns3/cdnsp-gadget.h
@@ -811,6 +811,7 @@ struct cdnsp_stream_info {
  *        generate Missed Service Error Event.
  *        Set skip flag when receive a Missed Service Error Event and
  *        process the missed tds on the endpoint ring.
+ * @wa1_nop_trb: hold pointer to NOP trb.
  */
 struct cdnsp_ep {
 	struct usb_ep endpoint;
@@ -838,6 +839,8 @@ struct cdnsp_ep {
 #define EP_UNCONFIGURED		BIT(7)
 
 	bool skip;
+	union cdnsp_trb	 *wa1_nop_trb;
+
 };
 
 /**
diff --git a/drivers/usb/cdns3/cdnsp-ring.c b/drivers/usb/cdns3/cdnsp-ring.c
index 02f297f5637d..dbd83d321bca 100644
--- a/drivers/usb/cdns3/cdnsp-ring.c
+++ b/drivers/usb/cdns3/cdnsp-ring.c
@@ -402,7 +402,7 @@ static u64 cdnsp_get_hw_deq(struct cdnsp_device *pdev,
 	struct cdnsp_stream_ctx *st_ctx;
 	struct cdnsp_ep *pep;
 
-	pep = &pdev->eps[stream_id];
+	pep = &pdev->eps[ep_index];
 
 	if (pep->ep_state & EP_HAS_STREAMS) {
 		st_ctx = &pep->stream_info.stream_ctx_array[stream_id];
@@ -1905,6 +1905,23 @@ int cdnsp_queue_bulk_tx(struct cdnsp_device *pdev, struct cdnsp_request *preq)
 		return ret;
 
 	/*
+	 * workaround 1: STOP EP command on LINK TRB with TC bit set to 1
+	 * causes that internal cycle bit can have incorrect state after
+	 * command complete. In consequence empty transfer ring can be
+	 * incorrectly detected when EP is resumed.
+	 * NOP TRB before LINK TRB avoid such scenario. STOP EP command is
+	 * then on NOP TRB and internal cycle bit is not changed and have
+	 * correct value.
+	 */
+	if (pep->wa1_nop_trb) {
+		field = le32_to_cpu(pep->wa1_nop_trb->trans_event.flags);
+		field ^= TRB_CYCLE;
+
+		pep->wa1_nop_trb->trans_event.flags = cpu_to_le32(field);
+		pep->wa1_nop_trb = NULL;
+	}
+
+	/*
 	 * Don't give the first TRB to the hardware (by toggling the cycle bit)
 	 * until we've finished creating all the other TRBs. The ring's cycle
 	 * state may change as we enqueue the other TRBs, so save it too.
@@ -1999,6 +2016,17 @@ int cdnsp_queue_bulk_tx(struct cdnsp_device *pdev, struct cdnsp_request *preq)
 		send_addr = addr;
 	}
 
+	if (cdnsp_trb_is_link(ring->enqueue + 1)) {
+		field = TRB_TYPE(TRB_TR_NOOP) | TRB_IOC;
+		if (!ring->cycle_state)
+			field |= TRB_CYCLE;
+
+		pep->wa1_nop_trb = ring->enqueue;
+
+		cdnsp_queue_trb(pdev, ring, 0, 0x0, 0x0,
+				TRB_INTR_TARGET(0), field);
+	}
+
 	cdnsp_check_trb_math(preq, enqd_len);
 	ret = cdnsp_giveback_first_trb(pdev, pep, preq->request.stream_id,
 				       start_cycle, start_trb);