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=-5.2 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED,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 EB65EC433DB for ; Sat, 6 Mar 2021 16:11:06 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id A63FD64EA4 for ; Sat, 6 Mar 2021 16:11:06 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230417AbhCFQHy (ORCPT ); Sat, 6 Mar 2021 11:07:54 -0500 Received: from netrider.rowland.org ([192.131.102.5]:40957 "HELO netrider.rowland.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with SMTP id S230329AbhCFQH1 (ORCPT ); Sat, 6 Mar 2021 11:07:27 -0500 Received: (qmail 74647 invoked by uid 1000); 6 Mar 2021 11:07:26 -0500 Date: Sat, 6 Mar 2021 11:07:26 -0500 From: Alan Stern To: Peter Chen Cc: Matthias Schwarzott , USB list , usb-storage@lists.one-eyed-alien.net, hirofumi@mail.parknet.co.jp Subject: Re: Amazon Kindle disconnect after Synchronize Cache Message-ID: <20210306160726.GB74411@rowland.harvard.edu> References: <9f57532f-1fb7-0fdd-b91c-2dfecef5aff3@gentoo.org> <20210305191437.GC48113@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 Sat, Mar 06, 2021 at 10:19:54AM +0800, Peter Chen wrote: > On Sat, Mar 6, 2021 at 3:17 AM Alan Stern wrote: > > Is runtime power management enabled? Maybe the Kindle disconnects > > whenever the computer tries to suspend it. This typically happens 2 > > seconds after the last command was issued, which matches your > > observations. If runtime PM is enabled, you can try disabling it. > > > > > Alan, I think you may be right. It might want to support the feature like > kindle goes to suspend after the Windows PC > enters suspend (but VBUS is there), the Windows PC may never suspend the > bus if a mass storage device is connected. That's possible. I have never tried to measure the bus activity when a Windows host is suspended. Alan Stern