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=-5.3 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, USER_AGENT_SANE_1 autolearn=no 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 6AE38C433E0 for ; Wed, 10 Mar 2021 21:47:39 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 152A164FD0 for ; Wed, 10 Mar 2021 21:47:39 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231994AbhCJVrF (ORCPT ); Wed, 10 Mar 2021 16:47:05 -0500 Received: from netrider.rowland.org ([192.131.102.5]:55473 "HELO netrider.rowland.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with SMTP id S231759AbhCJVqt (ORCPT ); Wed, 10 Mar 2021 16:46:49 -0500 Received: (qmail 236684 invoked by uid 1000); 10 Mar 2021 16:46:48 -0500 Date: Wed, 10 Mar 2021 16:46:48 -0500 From: Alan Stern To: Matthias Schwarzott Cc: linux-usb@vger.kernel.org, usb-storage@lists.one-eyed-alien.net, hirofumi@mail.parknet.co.jp Subject: Re: [usb-storage] Re: Amazon Kindle disconnect after Synchronize Cache Message-ID: <20210310214648.GA236329@rowland.harvard.edu> References: <9f57532f-1fb7-0fdd-b91c-2dfecef5aff3@gentoo.org> <20210305191437.GC48113@rowland.harvard.edu> <2a1f6636-6b57-ccc5-76b3-7eae5e80e7d3@gentoo.org> <20210307155236.GB103559@rowland.harvard.edu> <9c3121a9-3d0c-60b3-ef17-993b7d2e9149@gentoo.org> <20210307165856.GA104554@rowland.harvard.edu> <268e646f-d4ea-3190-f1b9-8e69bfc1b019@gentoo.org> <20210309155046.GA176674@rowland.harvard.edu> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.10.1 (2018-07-13) Precedence: bulk List-ID: X-Mailing-List: linux-usb@vger.kernel.org On Wed, Mar 10, 2021 at 09:56:04PM +0100, Matthias Schwarzott wrote: > > What happens if you set the value to 1000 before running the test? > > > I tested different values. At 1000 it still disconnects. At lower values it > no longer does this. > I tested 200 up to 900. Even 900 ms is good enough to keep it connected. > > Btw. it is not a USB disconnect, but it just seems to plays medium ejected. > > Out of interest I called "sg_start -v -l /dev/sde" after one of the failing > experiments. That made the Kindle go back to connected state. > > To me the above experiments show that enough TEST UNIT READY commands are > needed in the 2 s after a SYNCHRONIZE CACHE. So you have found the solution to your problem. Congratulations! Alan Stern