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 22A59C433F5 for ; Sat, 6 Nov 2021 14:41:57 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 03814611C4 for ; Sat, 6 Nov 2021 14:41:56 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234396AbhKFOog (ORCPT ); Sat, 6 Nov 2021 10:44:36 -0400 Received: from mail.kernel.org ([198.145.29.99]:53496 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231939AbhKFOof (ORCPT ); Sat, 6 Nov 2021 10:44:35 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id 2649561074; Sat, 6 Nov 2021 14:41:54 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1636209714; bh=EFQSWC2A+sX79AmgQ55mM3lCqICyKef/vVuUVtOUPQg=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=B5IpqBXMdalPSmjvlnYyi3YP7VMHGKHlDz/6TjOOZeIrivWSz086HWVdeXGyLo2S8 e3KTbd32XN9GYgi+d2+MIIK/AsFtMFwYMv1Mr/Cv0jUL+3NPZ40255JEXNDmW3F7Xs KJ1hZrmTTuNExDUxBlwaWuTytkEnyxVZYN11FEXE= Date: Sat, 6 Nov 2021 15:41:47 +0100 From: Greg KH To: Mathias Nyman 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 Subject: Re: [PATCH] xhci: Fix USB 3.1 enumeration issues by increasing roothub power-on-good delay Message-ID: References: <20211105133050.GA1590803@rowland.harvard.edu> <20211105160036.549516-1-mathias.nyman@linux.intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, Nov 05, 2021 at 09:56:59PM +0200, Mathias Nyman wrote: > 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. Great, I'll use that tag for now so that it will get backported properly. greg k-h