From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932529Ab1LEQwh (ORCPT ); Mon, 5 Dec 2011 11:52:37 -0500 Received: from www.linutronix.de ([62.245.132.108]:56325 "EHLO Galois.linutronix.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755038Ab1LEQwg (ORCPT ); Mon, 5 Dec 2011 11:52:36 -0500 Message-ID: <4EDCF6CF.6020902@linutronix.de> Date: Mon, 05 Dec 2011 17:52:31 +0100 From: Sebastian Andrzej Siewior User-Agent: Mozilla/5.0 (X11; U; Linux x86_64; en-US; rv:1.9.2.24) Gecko/20111114 Icedove/3.1.16 MIME-Version: 1.0 To: Alan Stern CC: Shimrit Malichi , Tatyana Brokhman , USB list , Kernel development list , target-devel@vger.kernel.org Subject: Re: [RFC] UASP on target References: In-Reply-To: Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit X-Linutronix-Spam-Score: -1.0 X-Linutronix-Spam-Level: - X-Linutronix-Spam-Status: No , -1.0 points, 5.0 required, ALL_TRUSTED=-1,SHORTCIRCUIT=-0.0001 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 12/05/2011 05:10 PM, Alan Stern wrote: > Evidently you were able to find enough information about the target > framework to write a driver using it. Can you tell us where this > information is? It hasn't been easy to locate. Hehe. Well, I've been told that the target framework has everything one needs to get it done so I've been digging in the code. First I tried to come up with an easy setup where I can use it. _This_ was already hard to get done for someone who is not familiar with scsi. Once I had all pieces together I wrote this [0].With this information I know more or less how that thing works or should work. So at this point I understood that I need to comeup with somethin like tcm_loop or tcm_vhost. Looking at the host side of the uas driver it is using SAS as the protocol and nothing special if you ignore "struct iu" for a moment. Then I found the python script in Documentation/target which creates you a skeleton driver. So I used this and started hacking. First I took the usb descriptors and looked what happens after I connected the dummy_hcd driver/gadget. I received a usb command message. So now I try to wire it up in target. I look at the loopback/vhost_scsi for some inspiration. Other than that I have no additional information.... [0] http://article.gmane.org/gmane.linux.scsi.target.devel/654 > Alan Stern Sebastian