DM USB: xHCI: use new isoch transfer implementation

The old implementation processes isoch TRB one by one, this method
can't support scenario which needs high performance, such as real
time USB camera video.

New implementions will compose all the isoch TRBs for one Door Bell
Ring, and give them to libusb as a single request. The test result
shows that this method could greatly improve the porfermance.

Tracked-On: #3054
Signed-off-by: Xiaoguang Wu <xiaoguang.wu@intel.com>
Acked-by: Yu Wang <yu1.wang@intel.com>

Author: xiaoguangwu

devicemodel/hw/pci/xhci.c

@@ -2586,6 +2586,7 @@ pci_xhci_xfer_complete(struct pci_xhci_vdev *xdev,
 	uint32_t edtla;
 	uint32_t i;
 	int  err = XHCI_TRB_ERROR_SUCCESS;
+	int rem_len = 0;
 
 	dev_ctx = pci_xhci_get_dev_ctx(xdev, slot);
 
@@ -2626,11 +2627,12 @@ pci_xhci_xfer_complete(struct pci_xhci_vdev *xdev,
 		trbflags = trb->dwTrb3;
 
 		UPRINTF(LDBG, "xfer[%d] done?%u:%d trb %x %016lx %x "
-			 "(err %d) IOC?%d\r\n",
+			 "(err %d) IOC?%d, chained %d\r\n",
 			 i, xfer->data[i].processed, xfer->data[i].blen,
 			 XHCI_TRB_3_TYPE_GET(trbflags), evtrb.qwTrb0,
 			 trbflags, err,
-			 trb->dwTrb3 & XHCI_TRB_3_IOC_BIT ? 1 : 0);
+			 trb->dwTrb3 & XHCI_TRB_3_IOC_BIT ? 1 : 0,
+			 xfer->data[i].chained);
 
 		if (xfer->data[i].processed < USB_XFER_BLK_HANDLED) {
 			xfer->head = (int)i;
@@ -2643,6 +2645,21 @@ pci_xhci_xfer_complete(struct pci_xhci_vdev *xdev,
 		edtla += xfer->data[i].bdone;
 
 		trb->dwTrb3 = (trb->dwTrb3 & ~0x1) | (xfer->data[i].ccs);
+		if (xfer->data[i].chained == 1) {
+			rem_len += xfer->data[i].blen;
+			i = (i + 1) % USB_MAX_XFER_BLOCKS;
+
+			/* When the chained == 1, this 'continue' will delay
+			 * the IOC behavior which could decrease the number
+			 * of virtual interrupts. This could GREATLY improve
+			 * the performance especially under ISOCH scenario.
+			 */
+			continue;
+		} else
+			rem_len += xfer->data[i].blen;
+
+		if (rem_len > 0)
+			err = XHCI_TRB_ERROR_SHORT_PKT;
 
 		/* Only interrupt if IOC or short packet */
 		if (!(trb->dwTrb3 & XHCI_TRB_3_IOC_BIT) &&
@@ -2654,7 +2671,7 @@ pci_xhci_xfer_complete(struct pci_xhci_vdev *xdev,
 		}
 
 		evtrb.dwTrb2 = XHCI_TRB_2_ERROR_SET(err) |
-			XHCI_TRB_2_REM_SET(xfer->data[i].blen);
+			XHCI_TRB_2_REM_SET(rem_len);
 
 		evtrb.dwTrb3 = XHCI_TRB_3_TYPE_SET(XHCI_TRB_EVENT_TRANSFER) |
 			XHCI_TRB_3_SLOT_SET(slot) | XHCI_TRB_3_EP_SET(epid);
@@ -2675,6 +2692,7 @@ pci_xhci_xfer_complete(struct pci_xhci_vdev *xdev,
 			break;
 
 		i = (i + 1) % USB_MAX_XFER_BLOCKS;
+		rem_len = 0;
 	}
 
 	return err;
@@ -2782,6 +2800,7 @@ pci_xhci_handle_transfer(struct pci_xhci_vdev *xdev,
 	uint32_t	trbflags;
 	int		do_intr, err;
 	int		do_retry;
+	bool		is_isoch = false;
 
 	ep_ctx->dwEpCtx0 = FIELD_REPLACE(ep_ctx->dwEpCtx0,
 					 XHCI_ST_EPCTX_RUNNING, 0x7, 0);
@@ -2858,8 +2877,11 @@ pci_xhci_handle_transfer(struct pci_xhci_vdev *xdev,
 			xfer_block->processed = USB_XFER_BLK_HANDLED;
 			break;
 
-		case XHCI_TRB_TYPE_NORMAL:
 		case XHCI_TRB_TYPE_ISOCH:
+			is_isoch = true;
+			/* fall through */
+
+		case XHCI_TRB_TYPE_NORMAL:
 			if (setup_trb != NULL) {
 				UPRINTF(LWRN, "trb not supposed to be in "
 					 "ctl scope\r\n");
@@ -2931,6 +2953,10 @@ pci_xhci_handle_transfer(struct pci_xhci_vdev *xdev,
 					xfer_block->trbnext, xfer_block->ccs);
 		}
 
+		if (is_isoch == true || XHCI_TRB_3_TYPE_GET(trbflags) ==
+				XHCI_TRB_TYPE_EVENT_DATA /* win10 needs it */)
+			continue;
+
 		/* handle current batch that requires interrupt on complete */
 		if (trbflags & XHCI_TRB_3_IOC_BIT) {
 			UPRINTF(LDBG, "trb IOC bit set\r\n");