From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-15.2 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 20C18C433F5 for ; Sat, 4 Sep 2021 16:09:54 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id F0FC46054E for ; Sat, 4 Sep 2021 16:09:53 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S236807AbhIDQKy (ORCPT ); Sat, 4 Sep 2021 12:10:54 -0400 Received: from netrider.rowland.org ([192.131.102.5]:60343 "HELO netrider.rowland.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with SMTP id S232298AbhIDQKy (ORCPT ); Sat, 4 Sep 2021 12:10:54 -0400 Received: (qmail 493669 invoked by uid 1000); 4 Sep 2021 12:09:51 -0400 Date: Sat, 4 Sep 2021 12:09:51 -0400 From: Alan Stern To: Florian Faber Cc: gregkh@linuxfoundation.org, linux-usb@vger.kernel.org Subject: Re: [PATCH] usb: gadget: f_mass_storage: Shut down mass storage device when USB connection is shut, down. Message-ID: <20210904160951.GA493355@rowland.harvard.edu> References: <5f9fbabd-2e2c-9389-446d-3bd1dd954a82@faberman.de> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <5f9fbabd-2e2c-9389-446d-3bd1dd954a82@faberman.de> User-Agent: Mutt/1.10.1 (2018-07-13) Precedence: bulk List-ID: X-Mailing-List: linux-usb@vger.kernel.org On Sat, Sep 04, 2021 at 05:32:58PM +0200, Florian Faber wrote: > f_mass_storage continues to send out packets after the connection to the USB > host has been terminated, ignoring the error status. The driver doesn't send packets after the connection has been terminated -- that would be impossible. It may _try_ to send packets, but it can't actually send anything unless the hosts asks for the data. There's nothing wrong with trying and failing. > Signed-off-by: Florian Faber > > --- > drivers/usb/gadget/function/f_mass_storage.c | 4 ++++ > 1 file changed, 4 insertions(+) > > diff --git a/drivers/usb/gadget/function/f_mass_storage.c > b/drivers/usb/gadget/function/f_mass_storage.c > index 6ad669dde41c..1e73ba629e43 100644 > --- a/drivers/usb/gadget/function/f_mass_storage.c > +++ b/drivers/usb/gadget/function/f_mass_storage.c > @@ -529,6 +529,10 @@ static int start_transfer(struct fsg_dev *fsg, struct > usb_ep *ep, > /* We can't do much more than wait for a reset */ > req->status = rc; > > + if (rc==-ESHUTDOWN) { > + fsg->common->running = 0; > + } > + This is wrong because it isn't what common->running means. common->running means that the mass-storage configuration has been set by the host; it has nothing to do with whether or not the USB cable is connected. Also the new code doesn't conform to the kernel's programming style (missing spaces around the "==" sign and braces not needed for a single-line conditional statement). And if it were a serious change, it should be merged with the conditional statement that follows, which also tests whether rc is -ESHUTDOWN. Alan Stern