From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757679AbcEEQFM (ORCPT ); Thu, 5 May 2016 12:05:12 -0400 Received: from mail-lf0-f66.google.com ([209.85.215.66]:36626 "EHLO mail-lf0-f66.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755653AbcEEQFJ (ORCPT ); Thu, 5 May 2016 12:05:09 -0400 Subject: Re: [PATCH v3 1/2] usb: host: ehci-tegra: Grab the correct UTMI pads reset To: Thierry Reding References: <1462372800-30900-1-git-send-email-thierry.reding@gmail.com> <20160504145710.GA14708@kroah.com> <20160504152648.GA31420@ulmo.ba.sec> Cc: Greg Kroah-Hartman , Alan Stern , Stephen Warren , Alexandre Courbot , Jon Hunter , linux-usb@vger.kernel.org, linux-tegra@vger.kernel.org, linux-kernel@vger.kernel.org, Tuomas Tynkkynen From: Tuomas Tynkkynen Message-ID: Date: Thu, 5 May 2016 19:05:05 +0300 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:45.0) Gecko/20100101 Thunderbird/45.0 MIME-Version: 1.0 In-Reply-To: <20160504152648.GA31420@ulmo.ba.sec> Content-Type: text/plain; charset=windows-1252; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 05/04/2016 06:26 PM, Thierry Reding wrote: > On Wed, May 04, 2016 at 07:57:10AM -0700, Greg Kroah-Hartman wrote: >> On Wed, May 04, 2016 at 04:39:59PM +0200, Thierry Reding wrote: >>> From: Thierry Reding >>> >>> There are three EHCI controllers on Tegra SoCs, each with its own reset >>> line. However, the first controller contains a set of UTMI configuration >>> registers that are shared with its siblings. These registers will only >>> be reset as part of the first controller's reset. For proper operation >>> it must be ensured that the UTMI configuration registers are reset >>> before any of the EHCI controllers are enabled, irrespective of the >>> probe order. >>> >>> Commit a47cc24cd1e5 ("USB: EHCI: tegra: Fix probe order issue leading to >>> broken USB") introduced code that ensures the first controller is always >>> reset before setting up any of the controllers, and is never again reset >>> afterwards. >>> >>> This code, however, grabs the wrong reset. Each EHCI controller has two >>> reset controls attached: 1) the USB controller reset and 2) the UTMI >>> pads reset (really the first controller's reset). In order to reset the >>> UTMI pads registers the code must grab the second reset, but instead it >>> grabbing the first. >>> >>> Signed-off-by: Thierry Reding ...snip ... > > While at it, adding Tuomas who wrote the original probe order fix. > Tuomas, does this patch look correct to you? Here's the patch in full if > you don't have it in your inbox: > > http://patchwork.ozlabs.org/patch/618488/ > D'oh! Yes, that patch looks correct. - Tuomas