Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755186Ab3CEIsl (ORCPT ); Tue, 5 Mar 2013 03:48:41 -0500 Received: from cantor2.suse.de ([195.135.220.15]:56913 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753536Ab3CEIsk (ORCPT ); Tue, 5 Mar 2013 03:48:40 -0500 From: Oliver Neukum To: "Fangxiaozhi (Franko)" Cc: =?ISO-8859-1?Q?Bj=F8rn?= Mork , "linux-usb@vger.kernel.org" , "linux-kernel@vger.kernel.org" , "Xueguiying (Zihan)" , "Linlei (Lei Lin)" , "greg@kroah.com" , "Yili (Neil)" , "Wangyuhua (Roger, Credit)" , "Huqiao (C)" , "balbi@ti.com" , "mdharm-usb@one-eyed-alien.net" , "sebastian@breakpoint.cc" Subject: Re: v3.8 regression: Huawei mode switching fails (was Re: [PATCH 2/2]linux-usb:optimize to match the Huawei USB storage devices and support new switch command) Date: Tue, 05 Mar 2013 09:48:55 +0100 Message-ID: <3774811.9hgnDZEBaM@linux-5eaq.site> Organization: SUSE User-Agent: KMail/4.8.5 (Linux/3.8.0-rc7-12-desktop+; KDE/4.8.5; x86_64; ; ) In-Reply-To: <910F9D9E13B84F4C8FA771DC9BDE99F327098368@szxeml546-mbx.china.huawei.com> References: <87obezs888.fsf@nemi.mork.no> <910F9D9E13B84F4C8FA771DC9BDE99F327098368@szxeml546-mbx.china.huawei.com> MIME-Version: 1.0 Content-Transfer-Encoding: 7Bit Content-Type: text/plain; charset="us-ascii" Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1299 Lines: 30 On Tuesday 05 March 2013 02:28:07 Fangxiaozhi wrote: Hi, > 1. As far as I know, usb_modeswitch is now only integrated in the PC Linux. It isn't integrated to other system with linux kernel, such as Android, Chrome OS, etc. On these system, how can we switch the device? Then those systems will have to add modeswitch. If we are to do mode switching in kernel space, there has to be an additional technical benefit over the existing and well working solution in user space. > 2. usb_modeswitch often sends the Windows switching command to switch Huawei device, but not sends Linux switching command. This maybe causes some unexpected problem. You have two commands? What is the difference? Anyway, if usb_modeswitch has issues, these problems need to be fixed. Independent from that, there is a problem with user space mode switching. Namely it doesn't work with reset_resume(). Thus we cannot do sane S4 with the user space solution. However, the problem cannot be solved by merely by adding the switch to the storage driver. Regards Oliver -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/