From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753181AbYIXKtU (ORCPT ); Wed, 24 Sep 2008 06:49:20 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751932AbYIXKtJ (ORCPT ); Wed, 24 Sep 2008 06:49:09 -0400 Received: from ns2.mvista.com ([63.81.120.155]:60126 "EHLO imap.sh.mvista.com" rhost-flags-OK-FAIL-OK-FAIL) by vger.kernel.org with ESMTP id S1751325AbYIXKtI (ORCPT ); Wed, 24 Sep 2008 06:49:08 -0400 Message-ID: <48DA1B1A.8050507@ru.mvista.com> Date: Wed, 24 Sep 2008 14:48:58 +0400 From: Sergei Shtylyov User-Agent: Thunderbird 2.0.0.16 (Windows/20080708) MIME-Version: 1.0 To: avorontsov@ru.mvista.com Cc: dbrownell@users.sourceforge.net, greg@kroah.com, linux-usb@vger.kernel.org, linux-kernel@vger.kernel.org, linuxppc-dev@ozlabs.org, Andrew Morton , leoli@freescale.com, timur@freescale.com Subject: Re: [PATCH 3/3] USB: driver for Freescale QUICC Engine USB Host Controller References: <20080918151659.GA20140@oksana.dev.rtsoft.ru> <20080918151746.GC31187@oksana.dev.rtsoft.ru> <20080919162324.e354ed2f.akpm@linux-foundation.org> <20080923183129.GA19024@oksana.dev.rtsoft.ru> <48D96052.6090005@ru.mvista.com> <48D9612D.7060601@ru.mvista.com> <20080923225730.GB13617@oksana.dev.rtsoft.ru> <48DA1544.5010307@ru.mvista.com> In-Reply-To: <48DA1544.5010307@ru.mvista.com> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hello, I wrote: >>>>>>> This controller does not integrate the root hub, so this driver >>>>>>> also >>>>>>> fakes one-port hub. External hub is required to support more than >>>>>>> one device. >>>>>>> >>>>>>> ... >>>>>>> >>>>>>> >>>>>> Please, no. >>>>>> >>>>> What exactly 'no'? ;-) >>>>> >>>> No one-port hubs I guess -- they are pointless. Though e.g. MUSB >>>> driver creates one -- I guess to impersonate a transaction >>>> translating high-speed hub... >>>> >>>> >>> ... then the root hub emulation is completely pointless. >>> >> >> It isn't. We always should emulate the root hub. The root hub >> is part and parcel of any USB Host. Even the one-port one. > > Hm, maybe that's what USB core thinks (because UHCI/OHCI/EHCI all > have it) but e.g. MUSB doesn't have the root hub registers... Oops, I stand corrected. Even USB 1.1 specifies that it must be a part the host... WBR, Sergei