From f37a3dc42fb08d7c4ebdeefb8c369b6c2f21a2e4 Mon Sep 17 00:00:00 2001
From: Vadim Galyant <vgal@rambler.ru>
Date: Mon, 22 Jan 2018 14:15:57 +0900
Subject: [PATCH] [USBPORT] Add USB2_BIT_STUFFING_OVERHEAD constant.

---
 drivers/usb/usbport/endpoint.c | 2 +-
 drivers/usb/usbport/usbport.h  | 2 ++
 2 files changed, 3 insertions(+), 1 deletion(-)

diff --git a/drivers/usb/usbport/endpoint.c b/drivers/usb/usbport/endpoint.c
index 2e9881bff2f..56ad3411b21 100644
--- a/drivers/usb/usbport/endpoint.c
+++ b/drivers/usb/usbport/endpoint.c
@@ -47,7 +47,7 @@ USBPORT_CalculateUsbBandwidth(IN PDEVICE_OBJECT FdoDevice,
     }
     else
     {
-        Bandwidth = (EndpointProperties->TotalMaxPacketSize + Overhead) * 8 * 7 / 6;
+        Bandwidth = (EndpointProperties->TotalMaxPacketSize + Overhead) * USB2_BIT_STUFFING_OVERHEAD;
     }
 
     if (EndpointProperties->DeviceSpeed == UsbLowSpeed)
diff --git a/drivers/usb/usbport/usbport.h b/drivers/usb/usbport/usbport.h
index 55c97e53307..20386f4845e 100644
--- a/drivers/usb/usbport/usbport.h
+++ b/drivers/usb/usbport/usbport.h
@@ -479,6 +479,8 @@ typedef struct _TIMER_WORK_QUEUE_ITEM {
 #define USB2_HS_SS_ISOCHRONOUS_IN_OVERHEAD     39
 #define USB2_HS_CS_ISOCHRONOUS_IN_OVERHEAD     38
 
+#define USB2_BIT_STUFFING_OVERHEAD  (8 * (7/6)) // 7.1.9 Bit Stuffing
+
 typedef union _USB2_TT_ENDPOINT_PARAMS {
   struct {
     ULONG TransferType           : 4;
-- 
2.17.1