diff --git a/Documentation/usb/error-codes.txt b/Documentation/usb/error-codes.txt
index d83703e..b3f606b 100644
--- a/Documentation/usb/error-codes.txt
+++ b/Documentation/usb/error-codes.txt
@@ -76,6 +76,13 @@
 reported.  That's because transfers often involve several packets, so that
 one or more packets could finish before an error stops further endpoint I/O.
 
+For isochronous URBs, the urb status value is non-zero only if the URB is
+unlinked, the device is removed, the host controller is disabled, or the total
+transferred length is less than the requested length and the URB_SHORT_NOT_OK
+flag is set.  Completion handlers for isochronous URBs should only see
+urb->status set to zero, -ENOENT, -ECONNRESET, -ESHUTDOWN, or -EREMOTEIO.
+Individual frame descriptor status fields may report more status codes.
+
 
 0			Transfer completed successfully
 
@@ -132,7 +139,7 @@
 			device removal events immediately.
 
 -EXDEV			ISO transfer only partially completed
-			look at individual frame status for details
+			(only set in iso_frame_desc[n].status, not urb->status)
 
 -EINVAL			ISO madness, if this happens: Log off and go home