From fa98307a3b82899ee157114a5742db09f768244d Mon Sep 17 00:00:00 2001
From: Robert Fisk <robert_fisk@fastmail.fm>
Date: Sun, 8 May 2016 15:27:03 +1200
Subject: [PATCH] HID class: handle host restart gracefully

---
 .../ST/STM32_USB_Device_Library/Class/HID/Src/usbd_hid.c | 1 -
 Upstream/Src/upstream_hid.c                              | 9 +++++++--
 2 files changed, 7 insertions(+), 3 deletions(-)

diff --git a/Upstream/Middlewares/ST/STM32_USB_Device_Library/Class/HID/Src/usbd_hid.c b/Upstream/Middlewares/ST/STM32_USB_Device_Library/Class/HID/Src/usbd_hid.c
index 968d258..5a35812 100644
--- a/Upstream/Middlewares/ST/STM32_USB_Device_Library/Class/HID/Src/usbd_hid.c
+++ b/Upstream/Middlewares/ST/STM32_USB_Device_Library/Class/HID/Src/usbd_hid.c
@@ -298,7 +298,6 @@ static uint8_t  USBD_HID_Init (USBD_HandleTypeDef *pdev,
 static uint8_t  USBD_HID_DeInit (USBD_HandleTypeDef *pdev, 
                                  uint8_t cfgidx)
 {
-  ActiveReportDescriptor = NULL;
   Upstream_HID_DeInit();
 
   /* Close HID EPs */
diff --git a/Upstream/Src/upstream_hid.c b/Upstream/Src/upstream_hid.c
index 0535233..dd7d1d5 100644
--- a/Upstream/Src/upstream_hid.c
+++ b/Upstream/Src/upstream_hid.c
@@ -55,6 +55,13 @@ HAL_StatusTypeDef Upstream_HID_GetNextReport(UpstreamHidSendReportCallback callb
         return HAL_ERROR;
     }
 
+    //Just return if we already have an outstanding request
+    if (ReportCallback != NULL)
+    {
+        return HAL_OK;
+    }
+    ReportCallback = callback;
+
     //Release packet used for last transaction (if any)
     if (UpstreamHidPacket != NULL)
     {
@@ -62,8 +69,6 @@ HAL_StatusTypeDef Upstream_HID_GetNextReport(UpstreamHidSendReportCallback callb
         UpstreamHidPacket = NULL;
     }
 
-    ReportCallback = callback;
-
     freePacket = Upstream_GetFreePacketImmediately();
     if (freePacket == NULL)
     {