Increase Downstream's host command timeout to 5 seconds. It turns out

some flash drives can take up to 2 seconds to write a single block.

Downstream/Middlewares/ST/STM32_USB_Host_Library/Class/MSC/Inc/usbh_msc.h

@@ -136,7 +136,8 @@ MSC_HandleTypeDef;
 #define USB_REQ_BOT_RESET                0xFF
 #define USB_REQ_GET_MAX_LUN              0xFE
 
-#define MSC_TIMEOUT_FRAMES_PER_BLOCK    1000
+//#define MSC_TIMEOUT_FRAMES_PER_BLOCK    1000
+#define MSC_TIMEOUT_FIXED               5000    //Some flash drives take 2 seconds to write a single block!
 
 /* MSC Class Codes */
 #define USB_MSC_CLASS                                   0x08

Downstream/Middlewares/ST/STM32_USB_Host_Library/Class/MSC/Src/usbh_msc.c

@@ -735,7 +735,7 @@ USBH_StatusTypeDef USBH_MSC_Read(USBH_HandleTypeDef *phost,
   MSC_Handle->unit[lun].state = MSC_READ;
   MSC_Handle->rw_lun = lun;
   MSC_Handle->RdWrCompleteCallback = callback;
-  MSC_Handle->timeout = phost->Timer + (length * MSC_TIMEOUT_FRAMES_PER_BLOCK);
+  MSC_Handle->timeout = phost->Timer + MSC_TIMEOUT_FIXED;
 
   USBH_MSC_SCSI_Read(phost,
                      lun,
@@ -776,7 +776,7 @@ USBH_StatusTypeDef USBH_MSC_Write(USBH_HandleTypeDef *phost,
   MSC_Handle->unit[lun].state = MSC_WRITE;
   MSC_Handle->rw_lun = lun;
   MSC_Handle->RdWrCompleteCallback = callback;
-  MSC_Handle->timeout = phost->Timer + (length * MSC_TIMEOUT_FRAMES_PER_BLOCK);
+  MSC_Handle->timeout = phost->Timer + MSC_TIMEOUT_FIXED;
 
   USBH_MSC_SCSI_Write(phost,
                      lun,