Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757579AbcDGUuq (ORCPT ); Thu, 7 Apr 2016 16:50:46 -0400 Received: from mail-wm0-f41.google.com ([74.125.82.41]:36559 "EHLO mail-wm0-f41.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757521AbcDGUuo (ORCPT ); Thu, 7 Apr 2016 16:50:44 -0400 Subject: Re: [PATCH] usb: f_mass_storage: test whether thread is running before starting another To: Alan Stern , Michal Nazarewicz References: <570672D0.4010102@gmail.com> Cc: Tony Lindgren , linux-kernel@vger.kernel.org, linux-usb@vger.kernel.org, Felipe Balbi , Bin Liu , pali.rohar@gmail.com From: Ivaylo Dimitrov Message-ID: <5706C81C.2080206@gmail.com> Date: Thu, 7 Apr 2016 23:50:36 +0300 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:38.0) Gecko/20100101 Thunderbird/38.6.0 MIME-Version: 1.0 In-Reply-To: <570672D0.4010102@gmail.com> Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1494 Lines: 43 Hi, On 7.04.2016 17:46, Ivaylo Dimitrov wrote: > > Hi, > > On 7.04.2016 17:25, Alan Stern wrote: >> On Thu, 7 Apr 2016, Michal Nazarewicz wrote: >> >>> Sounds good to me. I’d love someone to test this patch (I sadly have no >>> way of doing that at the moment) and with that I can resend it with >>> updated message. >> >> Ivaylo should be able to try it. >> > > I applied the patch agains 4.6-rc1 and while it seems there is no more > oops, trying to "cd /sys/bus/platform/drivers/musb-hdrc && echo > musb-hdrc.0.auto > unbind" still results in console hang. Will try to > find time later today and put printks all over the place to see what's > going on. > The $subject patch fixes the oops in fsg, so you may add: Tested-by: Ivaylo Dimitrov However, there is another problem, this time with f_acm - if there is an open /dev/ttyGSn device, it is impossible to reboot/power down the device. My investigation shows so far that there is a process(pnatd) that opens /dev/ttyGSn devices, so gserial_free_port() hangs on wait_event(port->close_wait, gs_closed(port)); if I do "cd /sys/bus/platform/drivers/musb-hdrc && echo musb-hdrc.0.auto > unbind". Unfortunately I don't have serial port connector on my N900, so I can't capture logs after the reboot command, however, I suspect it hangs on the same place as with unbind. That looks weird, as one would expect that close() is called when the kernel kills user processes on reboot/powerdown. Ivo