Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753690AbcCGVae (ORCPT ); Mon, 7 Mar 2016 16:30:34 -0500 Received: from mail-vk0-f51.google.com ([209.85.213.51]:36316 "EHLO mail-vk0-f51.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753132AbcCGVaZ convert rfc822-to-8bit (ORCPT ); Mon, 7 Mar 2016 16:30:25 -0500 MIME-Version: 1.0 In-Reply-To: <1400647253.149212.b3bb45b6-c852-4cf1-9d3e-9fb299176369.open-xchange@email.1und1.de> References: <1457115786-11370-1-git-send-email-dianders@chromium.org> <1457115786-11370-2-git-send-email-dianders@chromium.org> <1400647253.149212.b3bb45b6-c852-4cf1-9d3e-9fb299176369.open-xchange@email.1und1.de> Date: Mon, 7 Mar 2016 13:30:23 -0800 X-Google-Sender-Auth: eUBYcvPheSwddjFub1V3E3zaZzc Message-ID: Subject: Re: [RFT PATCH 2/2] Revert "usb: dwc2: Fix probe problem on bcm2835" From: Doug Anderson To: Stefan Wahren Cc: John Youn , Heiko Stuebner , Felipe Balbi , Michael Niewoehner , Tao Huang , Julius Werner , Greg Kroah-Hartman , "linux-kernel@vger.kernel.org" , "linux-usb@vger.kernel.org" , Caesar Wang , Remi Pommarel Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8BIT Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1178 Lines: 38 Stefan, On Mon, Mar 7, 2016 at 10:40 AM, Stefan Wahren wrote: > Hi Doug, > >> Douglas Anderson hat am 4. März 2016 um 19:23 >> geschrieben: >> >> >> This reverts commit 192cb07f7928 ("usb: dwc2: Fix probe problem on >> bcm2835") now that we've found the root cause. See the change >> titled ("usb: dwc2: Add a 10 ms delay to dwc2_core_reset()"). > > adding a delay of 10 ms after a core reset might be a idea, but applying both > patches breaks USB support on RPi :-( > > I'm getting the wrong register values ... Ugh. :( Just out of curiosity, if you loop and time long it takes for the registers to get to the right state after reset, what do you get? AKA, pick: https://chromium-review.googlesource.com/331260 ...and let me know what it prints out. On my system I see: [ 1.990743] dwc2 ff540000.usb: Waited 300001 us, 0x04000400 => 0x04000400, 0x02000800 => 0x02000800 [ 2.119677] dwc2 ff580000.usb: Waited 9997 us, 0x00100400 => 0x04000400, 0x00000000 => 0x02000800 I believe the difference in behavior is because of the two different types of USB controllers (one is OTG and the other is host only). -Doug