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 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 07DACC433F5 for ; Fri, 5 Nov 2021 19:55:39 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id E111960EB4 for ; Fri, 5 Nov 2021 19:55:38 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232908AbhKET6R (ORCPT ); Fri, 5 Nov 2021 15:58:17 -0400 Received: from mga17.intel.com ([192.55.52.151]:8884 "EHLO mga17.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232926AbhKET6Q (ORCPT ); Fri, 5 Nov 2021 15:58:16 -0400 X-IronPort-AV: E=McAfee;i="6200,9189,10159"; a="212714977" X-IronPort-AV: E=Sophos;i="5.87,212,1631602800"; d="scan'208";a="212714977" Received: from fmsmga001.fm.intel.com ([10.253.24.23]) by fmsmga107.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 05 Nov 2021 12:55:36 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.87,212,1631602800"; d="scan'208";a="639913030" Received: from mattu-haswell.fi.intel.com (HELO [10.237.72.199]) ([10.237.72.199]) by fmsmga001.fm.intel.com with ESMTP; 05 Nov 2021 12:55:33 -0700 To: Greg KH Cc: stern@rowland.harvard.edu, mr.yming81@gmail.com, chunfeng.yun@mediatek.com, matthias.bgg@gmail.com, nishadkamdar@gmail.com, linux-usb@vger.kernel.org, linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-mediatek@lists.infradead.org, eddie.hung@mediatek.com References: <20211105133050.GA1590803@rowland.harvard.edu> <20211105160036.549516-1-mathias.nyman@linux.intel.com> From: Mathias Nyman Subject: Re: [PATCH] xhci: Fix USB 3.1 enumeration issues by increasing roothub power-on-good delay Message-ID: Date: Fri, 5 Nov 2021 21:56:59 +0200 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:78.0) Gecko/20100101 Firefox/78.0 Thunderbird/78.8.1 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-usb@vger.kernel.org On 5.11.2021 18.15, Greg KH wrote: > On Fri, Nov 05, 2021 at 06:00:36PM +0200, Mathias Nyman wrote: >> Some USB 3.1 enumeration issues were reported after the hub driver removed >> the minimum 100ms limit for the power-on-good delay. >> >> Since commit 90d28fb53d4a ("usb: core: reduce power-on-good delay time of >> root hub") the hub driver sets the power-on-delay based on the >> bPwrOn2PwrGood value in the hub descriptor. >> >> xhci driver has a 20ms bPwrOn2PwrGood value for both roothubs based >> on xhci spec section 5.4.8, but it's clearly not enough for the >> USB 3.1 devices, causing enumeration issues. >> >> Tests indicate full 100ms delay is needed. >> >> Reported-by: Walt Jr. Brake >> Signed-off-by: Mathias Nyman > > So this needs: > Fixes: 90d28fb53d4a ("usb: core: reduce power-on-good delay time of root hub") > right? I guess so, not sure on "Fixes" policy here. This patch fixes an xhci issue revealed by ("usb: core: reduce power-on-good delay time of root hub") That original patch itself looks correct, but these two patches should really go together to avoid any enumeration issues. Thanks -Mathias