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=-1.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_PASS 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 A795FC43387 for ; Thu, 10 Jan 2019 13:05:53 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 6BB0820879 for ; Thu, 10 Jan 2019 13:05:53 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728235AbfAJNFw (ORCPT ); Thu, 10 Jan 2019 08:05:52 -0500 Received: from guitar.tcltek.co.il ([192.115.133.116]:52800 "EHLO mx.tkos.co.il" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726560AbfAJNFw (ORCPT ); Thu, 10 Jan 2019 08:05:52 -0500 Received: from tarshish (unknown [10.0.8.6]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mx.tkos.co.il (Postfix) with ESMTPS id 45E16440205; Thu, 10 Jan 2019 15:05:50 +0200 (IST) References: <024cc24efa7b99186750f90c91880b29357d379d.1547123182.git.baruch@tkos.co.il> <94cd23a60c647020dd87a923684b59255b89f02c.1547123182.git.baruch@tkos.co.il> <20190110125548.GA29612@lunn.ch> User-agent: mu4e 1.0; emacs 26.1 From: Baruch Siach To: Andrew Lunn Cc: Linus Walleij , Bartosz Golaszewski , Thierry Reding , Thomas Petazzoni , Lorenzo Pieralisi , Bjorn Helgaas , Sven Auhagen , linux-pwm@vger.kernel.org, linux-gpio@vger.kernel.org, linux-pci@vger.kernel.org, linux-arm-kernel@lists.infradead.org, Jason Cooper , Gregory Clement , Sebastian Hesselbarth Subject: Re: [PATCH 2/2] PCI: armada8k: don't toggle reset twice In-reply-to: <20190110125548.GA29612@lunn.ch> Date: Thu, 10 Jan 2019 15:05:49 +0200 Message-ID: <8736q0irwy.fsf@tarshish> MIME-Version: 1.0 Content-Type: text/plain Sender: linux-pci-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-pci@vger.kernel.org Hi Andrew, On Thu, Jan 10 2019, Andrew Lunn wrote: > On Thu, Jan 10, 2019 at 02:26:22PM +0200, Baruch Siach wrote: >> Commit 3d71746c42 ("PCI: armada8k: Add support for gpio controlled reset >> signal") added reset signal support. Reset is unconditionally asserted >> and deasserted. >> >> Unfortunately, that commit breaks boot on Macchiatobin when a Mellanox >> NIC is in the PCIe slot. >> >> It turns out that you can toggle the reset signal only once. Another >> reset signal toggle makes access to PCI configuration registers stall >> indefinitely. U-Boot toggles the Macchiatobin PCIe reset line already at >> boot. > > Hi Baruch > > Is this double reset issue limited to just Mellanox NICs, or any > device in the PCIe slot? > > This sounds more like a workaround than a fix. It would be good to > investigate further and determine which end of the PCIe link has the > problem. Sven Auhagen reported the same issue with Intel NIC attached to mini-PCIe slots on a custom Armada 8K design. How would you suggest to investigate this issue? baruch -- http://baruch.siach.name/blog/ ~. .~ Tk Open Systems =}------------------------------------------------ooO--U--Ooo------------{= - baruch@tkos.co.il - tel: +972.52.368.4656, http://www.tkos.co.il -