From mboxrd@z Thu Jan  1 00:00:00 1970
From: Mark Lord <liml@rtr.ca>
Subject: Re: libata fails to recover from HSM violation involving DRQ status
Date: Mon, 30 Apr 2007 20:23:38 -0400
Message-ID: <4636888A.10507@rtr.ca>
References: <4633AB75.7070107@rtr.ca>	<4633B0A6.6090705@garzik.org> <20070428222502.26fc9bbc@the-village.bc.nu> <4633BEE7.8020005@garzik.org> <4633BF6D.40902@rtr.ca> <46340E63.5070209@gmail.com> <4634163D.1040408@gmail.com> <463487F0.4040701@rtr.ca> <46349695.7080706@rtr.ca> <46349A03.9090300@rtr.ca> <4634CAEC.4010700@gmail.com> <4634CC18.4080208@rtr.ca> <4634E8B3.4050301@rtr.ca> <4634ED0D.1090709@rtr.ca> <46353E63.7070000@gmail.com> <46362BAC.4030909@rtr.ca>
Mime-Version: 1.0
Content-Type: text/plain; charset=ISO-8859-1; format=flowed
Content-Transfer-Encoding: 7bit
Return-path: <linux-ide-owner@vger.kernel.org>
Received: from rtr.ca ([64.26.128.89]:2411 "EHLO mail.rtr.ca"
	rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP
	id S1946199AbXEAAXl (ORCPT <rfc822;linux-ide@vger.kernel.org>);
	Mon, 30 Apr 2007 20:23:41 -0400
In-Reply-To: <46362BAC.4030909@rtr.ca>
Sender: linux-ide-owner@vger.kernel.org
List-Id: linux-ide@vger.kernel.org
To: Tejun Heo <htejun@gmail.com>
Cc: Jeff Garzik <jeff@garzik.org>, Alan Cox <alan@lxorguk.ukuu.org.uk>, Alan Cox <alan@redhat.com>, IDE/ATA development list <linux-ide@vger.kernel.org>

Mark Lord wrote:
> Tejun Heo wrote:
>> Mark Lord wrote:
>>> Mark Lord wrote:
>>>> ###### Test stuck DRQ on VIA-sata (disk):
>>>>
>>>> ata1.00: exception Emask 0x0 SAct 0x0 SErr 0x0 action 0x2 frozen
>>>> ata1.00: cmd ec/00:00:00:00:00/00:00:00:00:00/00 tag 0 cdb 0x0 data 0
>>>>         res 58/00:00:00:00:00/00:00:00:00:00/a0 Emask 0x2 (HSM 
>>>> violation)
>>> Why do we not always put a '\n' in front of that last line above ??
>>> Sometimes it seems to have it, and lots of times it does not have a 
>>> '\n'.
>>> Weird.
>>>
>>>> ###### Test stuck DRQ on VIA-pata (ATAPI DVD/RW):
>>>> ###### Notice how the first "ata4.00: cmd ..." line is *missing*:
>>>>
>>>>         res 58/00:02:00:00:02/00:00:00:00:00/40 Emask 0x2 (HSM 
>>>> violation)
>>>> ata4: soft resetting port
>>>> ata4.00: configured for UDMA/66
>>>> ata4: EH complete
>>> And in this case, the first line of diagnostics (the "cmd" line)
>>> is always missing.  Why?
..
> Well, from looking at the code, we see that the last thing
> before the "res" line is a "%s" for dma_str[qc->dma_dir].
> If qc->dma_dir is corrupted (or just not set), then we'll get
> semi-random garbage, which must be what's happening here.

WRONG.  The qc->dma_dir turns out to be just fine (3) in this case.

And.. the messages look fine with "dmesg", but syslogd records only
the "res.." line in /var/log/messages.

Too kooky for me.