From mboxrd@z Thu Jan 1 00:00:00 1970 From: Douglas Gilbert Subject: Re: Bugs in scsi_vpd_inquiry() Date: Mon, 10 Aug 2009 17:53:51 -0400 Message-ID: <4A8096EF.6010508@interlog.com> References: Reply-To: dgilbert@interlog.com Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii; format=flowed Content-Transfer-Encoding: 7bit Return-path: Received: from smtp.infotech.no ([82.134.31.41]:48105 "EHLO elrond.infotech.no" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753939AbZHJVxy (ORCPT ); Mon, 10 Aug 2009 17:53:54 -0400 In-Reply-To: Sender: linux-scsi-owner@vger.kernel.org List-Id: linux-scsi@vger.kernel.org To: "Martin K. Petersen" Cc: Alan Stern , Matthew Wilcox , Matthew Wilcox , SCSI development list Martin K. Petersen wrote: >>>>>> "Alan" == Alan Stern writes: > > Alan, > >>>> data always to be accurate may not be a good idea. I'm considering >>>> adding a "restrict_to_MS_usb" flag to the host template, to >>>> indicate that commands shouldn't be sent unless some version of >>>> Windows uses them when talking to USB devices -- do you think that >>>> could work? >>> Not really my area of expertise. > > Alan> Okay. Maybe Martin has some thoughts on it. > > First of all we're not going to send EVPD=1 out to devices reporting > SCSI_SPC_2 or lower anymore, making some of this discussion moot in the > short term. > > But as I have alluded to in the past we do have a conflict brewing > because the switch to drives with 4KB physical blocks will mean USB > bridges will have to get smarter. And that in turn will mean adhering > (*gasp*) to the standard instead of firmware writers flipping bits until > Windows stops crashing. Windows 7 does in fact query drives about > alignment, block sizes, etc. But I'm not sure how true that is for the > Windows USB storage stack. It would be interesting to know if Windows 7 is pushing UAS (USB attached SCSI) [latest draft at www.t10.org is uas-r02.pdf]. "USB Attached SCSI is a new generation of USB Transport Standards. This standard supports the following features in support of USB-20 and future USB specifications: a) does not interfere with the USB Mass Storage Class (MSC) bulk-only transport; b) mechanism to send commands associated with any T10 standard to a USB device; c) support for queuing in the protocol; d) support for autosense; e) compliance with SCSI Architecture Model - 4 (SAM-4) or later; and f) other capabilities." It is at the letter ballot stage at t10. Doug Gilbert