From b902669a0a8603a6427081e6ca69cabe3a9ee47a Mon Sep 17 00:00:00 2001
From: Michael McMaster <michael@codesrc.com>
Date: Sat, 29 Jan 2022 22:41:39 +1000
Subject: [PATCH] Workaround for Windows handling USB errors when no SD card
 inserted

---
 CHANGELOG                               |  4 ++++
 src/firmware/config.c                   |  2 +-
 src/firmware/usb_device/usbd_msc_scsi.c | 32 ++++++++++++++++++++++---
 3 files changed, 34 insertions(+), 4 deletions(-)

diff --git a/CHANGELOG b/CHANGELOG
index 2fe7e7fb..a3857832 100644
--- a/CHANGELOG
+++ b/CHANGELOG
@@ -1,3 +1,7 @@
+2022xxxx        6.4.14
+    - Fix firmware version displaying as "0.0" in scsi2sd-util when there is no
+    SD card inserted.
+
 20220121        6.4.13
     - Fix SCSI writes with sector sizes larger than 512.
     - Fix 2Gb SD cards being detected as 1Gb
diff --git a/src/firmware/config.c b/src/firmware/config.c
index 451ad623..3863d397 100755
--- a/src/firmware/config.c
+++ b/src/firmware/config.c
@@ -36,7 +36,7 @@
 
 #include <string.h>
 
-static const uint16_t FIRMWARE_VERSION = 0x064D;
+static const uint16_t FIRMWARE_VERSION = 0x064E;
 
 // Optional static config
 extern uint8_t* __fixed_config;
diff --git a/src/firmware/usb_device/usbd_msc_scsi.c b/src/firmware/usb_device/usbd_msc_scsi.c
index 9ebccb8c..9c2f139c 100755
--- a/src/firmware/usb_device/usbd_msc_scsi.c
+++ b/src/firmware/usb_device/usbd_msc_scsi.c
@@ -267,12 +267,38 @@ static int8_t SCSI_ReadCapacity10(USBD_HandleTypeDef  *pdev, uint8_t lun, uint8_
   
   if(((USBD_StorageTypeDef *)pdev->pUserData)->GetCapacity(lun, &hmsc->scsi_blk_nbr, &hmsc->scsi_blk_size) != 0)
   {
-    SCSI_SenseCode(pdev,
+    memset(hmsc->bot_data, 0, 8);
+    if (hmsc->bot_state == USBD_BOT_DATA_IN)
+    {
+        if (hmsc->bot_data_length > 0)
+        {
+            USBD_LL_Transmit (pdev, 
+                MSC_EPIN_ADDR,
+                hmsc->bot_data,
+                hmsc->bot_data_length);
+            hmsc->csw.dDataResidue -= hmsc->bot_data_length;
+            hmsc->bot_data_length = 0;
+            return 0;
+        }
+        else
+        {
+            return -1; // Time to send the error.
+        }
+    }
+    else
+    {
+        SCSI_SenseCode(pdev,
                    lun,
                    NOT_READY, 
                    MEDIUM_NOT_PRESENT);
-    hmsc->bot_state = USBD_BOT_NO_DATA;
-    return -1;
+
+        // Don't send the error just yet. Microsoft Windows fails to detect the CSW
+        // prior to the 8 byte response is sent. Windows also insists on calling
+        // ReadCapacity even when TestUnitReady fails with MEDIUM_NOT_PRESENT
+        hmsc->bot_state = USBD_BOT_DATA_IN;
+        hmsc->bot_data_length = MIN(8, hmsc->csw.dDataResidue);
+        return 0;
+    }
   } 
   else
   {
-- 
2.38.5