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=-3.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS,URIBL_BLOCKED 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 48F8BECDE43 for ; Fri, 19 Oct 2018 14:05:56 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id EB40121476 for ; Fri, 19 Oct 2018 14:05:55 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org EB40121476 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=rowland.harvard.edu Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727550AbeJSWMK (ORCPT ); Fri, 19 Oct 2018 18:12:10 -0400 Received: from iolanthe.rowland.org ([192.131.102.54]:38106 "HELO iolanthe.rowland.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with SMTP id S1727378AbeJSWMK (ORCPT ); Fri, 19 Oct 2018 18:12:10 -0400 Received: (qmail 1578 invoked by uid 2102); 19 Oct 2018 10:05:52 -0400 Received: from localhost (sendmail-bs@127.0.0.1) by localhost with SMTP; 19 Oct 2018 10:05:52 -0400 Date: Fri, 19 Oct 2018 10:05:52 -0400 (EDT) From: Alan Stern X-X-Sender: stern@iolanthe.rowland.org To: Kai-Heng Feng cc: gregkh@linuxfoundation.org, , Subject: Re: [PATCH v2] USB: Wait for extra delay time after USB_PORT_FEAT_RESET for quirky hub In-Reply-To: <20181019081450.21230-1-kai.heng.feng@canonical.com> Message-ID: MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, 19 Oct 2018, Kai-Heng Feng wrote: > Devices connected under Terminus Technology Inc. Hub (1a40:0101) may > fail to work after the system resumes from suspend: > [ 206.063325] usb 3-2.4: reset full-speed USB device number 4 using xhci_hcd > [ 206.143691] usb 3-2.4: device descriptor read/64, error -32 > [ 206.351671] usb 3-2.4: device descriptor read/64, error -32 > > Info for this hub: > T: Bus=03 Lev=01 Prnt=01 Port=01 Cnt=01 Dev#= 2 Spd=480 MxCh= 4 > D: Ver= 2.00 Cls=09(hub ) Sub=00 Prot=01 MxPS=64 #Cfgs= 1 > P: Vendor=1a40 ProdID=0101 Rev=01.11 > S: Product=USB 2.0 Hub > C: #Ifs= 1 Cfg#= 1 Atr=e0 MxPwr=100mA > I: If#= 0 Alt= 0 #EPs= 1 Cls=09(hub ) Sub=00 Prot=00 Driver=hub > > Some expirements indicate that the USB devices connected to the hub are > innocent, it's the hub itself is to blame. The hub needs extra delay > time after it resets its port. > > Hence wait for extra delay, if the device is connected to this quirky > hub. > > Signed-off-by: Kai-Heng Feng > --- > v2: > - Use hub->hdev to check quirk. > - Merge the delay with TRSTRCY. Acked-by: Alan Stern