[src/trunk]: src/sys/dev/usb For interrupt transfer, nak throttling must be d...

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

details:   https://anonhg.NetBSD.org/src/rev/2a51616e4aee
branches:  trunk
changeset: 756141:2a51616e4aee
user:      msaitoh <msaitoh%NetBSD.org@localhost>
date:      Wed Jul 07 03:55:01 2010 +0000

description:
For interrupt transfer, nak throttling must be disabled, but for the other
transfer type, nak throttling should be enabled from the veiwpoint that
avoids the memory thrashing. Fixes a problem that interrupt transfer stall
on some EHCI controllers (e.g. Geode LX). Fixed by Yamada Katsumi.

diffstat:

 sys/dev/usb/ehci.c |  12 +++++++++---
 1 files changed, 9 insertions(+), 3 deletions(-)

diffs (33 lines):

diff -r 7b4f7e40ba05 -r 2a51616e4aee sys/dev/usb/ehci.c
--- a/sys/dev/usb/ehci.c        Wed Jul 07 01:37:35 2010 +0000
+++ b/sys/dev/usb/ehci.c        Wed Jul 07 03:55:01 2010 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: ehci.c,v 1.168 2010/06/02 18:53:39 jakllsch Exp $ */
+/*     $NetBSD: ehci.c,v 1.169 2010/07/07 03:55:01 msaitoh Exp $ */
 
 /*
  * Copyright (c) 2004-2008 The NetBSD Foundation, Inc.
@@ -52,7 +52,7 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: ehci.c,v 1.168 2010/06/02 18:53:39 jakllsch Exp $");
+__KERNEL_RCSID(0, "$NetBSD: ehci.c,v 1.169 2010/07/07 03:55:01 msaitoh Exp $");
 
 #include "ohci.h"
 #include "uhci.h"
@@ -1581,7 +1581,13 @@
                return USBD_INVAL;
        }
 
-       naks = 8;               /* XXX */
+       /*
+        * For interrupt transfer, nak throttling must be disabled, but for
+        * the other transfer type, nak throttling should be enabled from the
+        * veiwpoint that avoids the memory thrashing.
+        */
+       naks = (xfertype == UE_INTERRUPT) ? 0
+           : ((speed == EHCI_QH_SPEED_HIGH) ? 4 : 0);
 
        /* Allocate sqh for everything, save isoc xfers */
        if (xfertype != UE_ISOCHRONOUS) {