From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754773AbaFNNKi (ORCPT ); Sat, 14 Jun 2014 09:10:38 -0400 Received: from mail1.windriver.com ([147.11.146.13]:32979 "EHLO mail1.windriver.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754679AbaFNNKh (ORCPT ); Sat, 14 Jun 2014 09:10:37 -0400 Message-ID: <539C49B3.7000606@windriver.com> Date: Sat, 14 Jun 2014 21:10:11 +0800 From: "Yang,Wei" User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:24.0) Gecko/20100101 Thunderbird/24.0 MIME-Version: 1.0 To: Alan Stern CC: , , , , Subject: Re: [PATCH v3] USB:gadget: Fix a warning while loading g_mass_storage References: In-Reply-To: Content-Type: text/plain; charset="ISO-8859-1"; format=flowed Content-Transfer-Encoding: 7bit X-Originating-IP: [128.224.162.170] Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 06/13/2014 09:39 PM, Alan Stern wrote: > On Fri, 13 Jun 2014, Yang,Wei wrote: > >> On 06/09/2014 02:19 PM, Wei.Yang@windriver.com wrote: >>> From: Yang Wei >>> >>> While loading g_mass_storage module, the following warning >>> is triggered. >>> >>> WARNING: at drivers/usb/gadget/composite.c: >>> usb_composite_setup_continue: Unexpected call >>> Modules linked in: fat vfat minix nls_cp437 nls_iso8859_1 g_mass_storage >>> [<800179cc>] (unwind_backtrace+0x0/0x104) from [<80619608>] (dump_stack+0x20/0x24) >>> [<80619608>] (dump_stack+0x20/0x24) from [<80025100>] (warn_slowpath_common+0x64/0x74) >>> [<80025100>] (warn_slowpath_common+0x64/0x74) from [<800251cc>] (warn_slowpath_fmt+0x40/0x48) >>> [<800251cc>] (warn_slowpath_fmt+0x40/0x48) from [<7f047774>] (usb_composite_setup_continue+0xb4/0xbc [g_mass_storage]) >>> [<7f047774>] (usb_composite_setup_continue+0xb4/0xbc [g_mass_storage]) from [<7f047ad4>] (handle_exception+0x358/0x3e4 [g_mass_storage]) >>> [<7f047ad4>] (handle_exception+0x358/0x3e4 [g_mass_storage]) from [<7f048080>] (fsg_main_thread+0x520/0x157c [g_mass_storage]) >>> [<7f048080>] (fsg_main_thread+0x520/0x157c [g_mass_storage]) from [<8004bc90>] (kthread+0x98/0x9c) >>> [<8004bc90>] (kthread+0x98/0x9c) from [<8000faec>] (kernel_thread_exit+0x0/0x8) >>> >>> The root cause is that the existing code fails to take into >>> account the possibility that common->new_fsg can change while >>> do_set_interface() is running, because the spinlock isn't held >>> at this point. >>> >>> Signed-off-by: Yang Wei >>> Signed-off-by: Alan Stern >>> --- >>> drivers/usb/gadget/f_mass_storage.c | 6 ++++-- >>> 1 file changed, 4 insertions(+), 2 deletions(-) >>> >>> Hi Alan, >>> >>> Thanks for your review, there are a few changes in v3: >>> >>> 1) Fix a coding style issue. >>> 2) Refine the commit log >>> >>> Regards >>> Wei >> Ping, Alan, What do you think of it? > You should not have added my "Signed-off-by:"; I did not give you > permission to do that. Sorry for it, I considered that you give me a few advice and hep me to refine the commit log, so I added your signed off. Sorry again! > > Michal's comment about common->new_fsg not being protected by the lock > is a good one. It would be better for the patch description to say: > > The value of common->new_fsg that gets tested after > do_set_interface() returns needs to be the same as the value > used by do_set_interface(). > > With that change, you may add > > Acked-by: Alan Stern Okay, I would use the above description in v4. Regards Wei > > Alan Stern > > >