NetBSD Problem Report #42375
From Wolfgang.Stukenbrock@nagler-company.com Wed Nov 25 10:50:23 2009
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Date: Wed, 25 Nov 2009 11:50:19 +0100 (CET)
From: Wolfgang.Stukenbrock@nagler-company.com
Reply-To: Wolfgang.Stukenbrock@nagler-company.com
To: gnats-bugs@gnats.NetBSD.org
Subject: ahd driver uses wrong mask if CND-queuing failed
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>Number: 42375
>Category: kern
>Synopsis: ahd driver uses wrong mask if CND-queuing failed
>Confidential: no
>Severity: serious
>Priority: medium
>Responsible: kern-bug-people
>State: open
>Class: sw-bug
>Submitter-Id: net
>Arrival-Date: Wed Nov 25 10:55:00 +0000 2009
>Originator: W. Stukenbrock
>Release: NetBSD 4.0
>Organization:
Dr. Nagler & Company GmbH
>Environment:
System: NetBSD test-s0 4.0 NetBSD 4.0 (NSW-WS) #2: Fri Nov 6 11:14:49 CET 2009 wgstuken@s012:/export/NetBSD-4.0/N+C-build/.OBJDIR_amd64/export/NetBSD-4.0/src/sys/arch/amd64/compile/NSW-WS amd64
Architecture: x86_64
Machine: amd64
>Description:
If a device rejects comamnd-queing as requested by the host,
the fallback switching code in the ahd driver is broken.
It checks the control byte with the simple-queue mask (this is not
100% OK, but it would work ...) and than tries to check the tag_type
if it it is simple queuing or something more sofisticated.
If it was only simple it will turn of cmd-queuing for that device,
otherwiese the driver next tries simple queuing mode.
Here is the bug: while masking the relevant bits, some bits are
lost.
>How-To-Repeat:
Found by a look into the source.
It would happen if someone setup a device to use an advanced queing
mode, but that device does not support it.
>Fix:
The problem is located in /usr/src/sys/dev/ic/aic79xx.c.
The following patch will fix this problem:
--- aic79xx.c 2008/09/26 11:28:03 1.2
+++ aic79xx.c 2009/11/25 10:10:13
@@ -4672,11 +4672,16 @@
"Using asynchronous transfers\n",
ahd_name(ahd), devinfo->channel,
devinfo->target, devinfo->lun);
- } else if ((scb->hscb->control & MSG_SIMPLE_TASK) != 0) {
+ } else if ((scb->hscb->control & 0x23) != 0) {
+/* remark: cannot use MSG_SIMPLE_TASK here - other bits are also needed
+ * the mask 0x23 is used below - so use it here too
+ *
+ * W. Stukenbrock 25.11.2009
+ */
int tag_type;
int mask;
- tag_type = (scb->hscb->control & MSG_SIMPLE_TASK);
+ tag_type = (scb->hscb->control & 0x23);
if (tag_type == MSG_SIMPLE_TASK) {
printf("(%s:%c:%d:%d): refuses tagged commands. "
>Unformatted:
(Contact us)
$NetBSD: query-full-pr,v 1.39 2013/11/01 18:47:49 spz Exp $
$NetBSD: gnats_config.sh,v 1.8 2006/05/07 09:23:38 tsutsui Exp $
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