anchor.diff:  (defun parse-read-capacity (usbd device mass-storage cap/10-p)
     (enter-function "parse-read-capacity")
   
  -  (let ((data-length (if cap/10-p 8 32)))
  +  (let ((data-length (if cap/10-p 8 32))
  +        (event (mass-storage-event mass-storage)))
       (with-buffers ((buf-pool usbd) ((cmd-buf /8 31)
                                       (data-buf /8 data-length)
                                       (status-buf /8 13)))
  
positive.code:         (sup:debug-print-line "inquiry command buffer:")
          (print-buffer sys.int::*cold-stream* cmd-buf :indent "  "))
  
        (sync:semaphore-down (mass-storage-semaphore mass-storage))
  
        (with-trace-level (4)
          (sup:debug-print-line "inquiry command status"
                                (mass-storage-status mass-storage)))
  
        (bulk-enqueue-buf usbd
                          device
                          (mass-storage-bulk-in-endpt-num mass-storage)
                          data-buf
                          data-length)
  
        (sync:semaphore-down (mass-storage-semaphore mass-storage))
  
        (with-trace-level (3)
          (sup:debug-print-line "inquiry data buffer:")
  
negative.code:         (sup:debug-print-line "read capacity data status "
                                (mass-storage-status mass-storage)))
  
        (setf (sup:event-state event) nil)
        (bulk-enqueue-buf usbd
                          device
                          (mass-storage-bulk-in-endpt-num mass-storage)
                          status-buf
                          13)
  
        (when (eq (timed-wait event 1.0) :timeout)
          ;; TODO need better error message here
          (error "Mass storage read capacity status timeout"))
  
        (with-trace-level (4)
          (sup:debug-print-line "read capacity status buffer:")
  