From mboxrd@z Thu Jan  1 00:00:00 1970
Received: from eggs.gnu.org ([208.118.235.92]:59902)
	by lists.gnu.org with esmtp (Exim 4.71)
	(envelope-from <kraxel@redhat.com>) id 1US7yC-0002G6-Db
	for qemu-devel@nongnu.org; Tue, 16 Apr 2013 11:38:57 -0400
Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71)
	(envelope-from <kraxel@redhat.com>) id 1US7y7-0004ds-7H
	for qemu-devel@nongnu.org; Tue, 16 Apr 2013 11:38:56 -0400
Received: from mx1.redhat.com ([209.132.183.28]:63157)
	by eggs.gnu.org with esmtp (Exim 4.71)
	(envelope-from <kraxel@redhat.com>) id 1US7y6-0004dk-Vl
	for qemu-devel@nongnu.org; Tue, 16 Apr 2013 11:38:51 -0400
Message-ID: <516D7082.9090101@redhat.com>
Date: Tue, 16 Apr 2013 17:38:42 +0200
From: Gerd Hoffmann <kraxel@redhat.com>
MIME-Version: 1.0
References: <Pine.LNX.4.44L0.1304161048280.1391-100000@iolanthe.rowland.org>
In-Reply-To: <Pine.LNX.4.44L0.1304161048280.1391-100000@iolanthe.rowland.org>
Content-Type: text/plain; charset=ISO-8859-1
Content-Transfer-Encoding: 7bit
Subject: Re: [Qemu-devel] USB2.0 disk format failure in windows guest
List-Id: <qemu-devel.nongnu.org>
List-Unsubscribe: <https://lists.nongnu.org/mailman/options/qemu-devel>,
	<mailto:qemu-devel-request@nongnu.org?subject=unsubscribe>
List-Archive: <http://lists.nongnu.org/archive/html/qemu-devel>
List-Post: <mailto:qemu-devel@nongnu.org>
List-Help: <mailto:qemu-devel-request@nongnu.org?subject=help>
List-Subscribe: <https://lists.nongnu.org/mailman/listinfo/qemu-devel>,
	<mailto:qemu-devel-request@nongnu.org?subject=subscribe>
To: Alan Stern <stern@rowland.harvard.edu>
Cc: Yanqiangjun <yanqiangjun@huawei.com>, Hanweidong <hanweidong@huawei.com>, "linux-usb@vger.kernel.org" <linux-usb@vger.kernel.org>, Luonengjun <luonengjun@huawei.com>, "qemu-devel@nongnu.org" <qemu-devel@nongnu.org>, "hdegoede@redhat.com" <hdegoede@redhat.com>, "Gonglei (Arei)" <arei.gonglei@huawei.com>

  Hi,

> Fixing this will require qemu to copy the beginning and ending parts of
> these non-aligned qTDs into separate bounce buffers so that the URB
> length can be divisible by 512.

Worth trying:  http://www.kraxel.org/cgit/qemu/log/?h=usb.80

It puts the qemu usb passthrough code upside down.  All xfers will go
through a bounce buffer, requests are submitted via libusbx.  That
should fix it.  Of course there is the risk of regressions in other
areas as it is all new code.  Also make sure you have libusbx-devel
installed, otherwise qemu will fallback to the old code which uses usbfs
ioctls directly.

cheers,
  Gerd