[src/trunk]: src/sys/dev/usb Add a comment.

[augustss <augustss%NetBSD.org@localhost>]

details:   https://anonhg.NetBSD.org/src/rev/6bf8ae2d3cfb
branches:  trunk
changeset: 570706:6bf8ae2d3cfb
user:      augustss <augustss%NetBSD.org@localhost>
date:      Sun Oct 24 22:13:52 2004 +0000

description:
Add a comment.

diffstat:

 sys/dev/usb/ehci.c |  10 +++++++---
 1 files changed, 7 insertions(+), 3 deletions(-)

diffs (31 lines):

diff -r d05c61ef96a5 -r 6bf8ae2d3cfb sys/dev/usb/ehci.c
--- a/sys/dev/usb/ehci.c        Sun Oct 24 22:12:24 2004 +0000
+++ b/sys/dev/usb/ehci.c        Sun Oct 24 22:13:52 2004 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: ehci.c,v 1.85 2004/10/24 22:12:24 augustss Exp $ */
+/*     $NetBSD: ehci.c,v 1.86 2004/10/24 22:13:52 augustss Exp $ */
 
 /*
  * Copyright (c) 2004 The NetBSD Foundation, Inc.
@@ -65,7 +65,7 @@
 */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: ehci.c,v 1.85 2004/10/24 22:12:24 augustss Exp $");
+__KERNEL_RCSID(0, "$NetBSD: ehci.c,v 1.86 2004/10/24 22:13:52 augustss Exp $");
 
 #include "ohci.h"
 #include "uhci.h"
@@ -797,7 +797,11 @@
                        actlen += sqtd->len - EHCI_QTD_GET_BYTES(status);
        }
 
-       /* If there are left over TDs we need to update the toggle. */
+       /* 
+        * If there are left over TDs we need to update the toggle.
+        * The default pipe doesn't need it since control transfers
+        * start the toggle at 0 every time.
+        */
        if (sqtd != lsqtd->nextqtd && 
            xfer->pipe->device->default_pipe != xfer->pipe) {
                printf("ehci_idone: need toggle update status=%08x nstatus=%08x\n", status, nstatus);