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,URIBL_BLOCKED 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 AEA69C43387 for ; Sun, 13 Jan 2019 20:01:03 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 8A7A920675 for ; Sun, 13 Jan 2019 20:01:03 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726823AbfAMUBC (ORCPT ); Sun, 13 Jan 2019 15:01:02 -0500 Received: from guitar.tcltek.co.il ([192.115.133.116]:52949 "EHLO mx.tkos.co.il" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726819AbfAMUBB (ORCPT ); Sun, 13 Jan 2019 15:01:01 -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 ACA5B4400E1; Sun, 13 Jan 2019 20:42:22 +0200 (IST) References: <024cc24efa7b99186750f90c91880b29357d379d.1547123182.git.baruch@tkos.co.il> <94cd23a60c647020dd87a923684b59255b89f02c.1547123182.git.baruch@tkos.co.il> <20190110125548.GA29612@lunn.ch> <8736q0irwy.fsf@tarshish> <20190110131912.GB29612@lunn.ch> <87zhs8h5ej.fsf@tarshish> <87pnt0vil3.fsf@tarshish> <20190113154028.GB4635@lunn.ch> User-agent: mu4e 1.0; emacs 26.1 From: Baruch Siach To: Andrew Lunn Cc: linux-pwm@vger.kernel.org, Lorenzo Pieralisi , Sven Auhagen , Jason Cooper , linux-gpio@vger.kernel.org, linux-pci@vger.kernel.org, Linus Walleij , Bartosz Golaszewski , Thierry Reding , Thomas Petazzoni , Bjorn Helgaas , Gregory Clement , linux-arm-kernel@lists.infradead.org, Sebastian Hesselbarth Subject: Re: [PATCH 2/2] PCI: armada8k: don't toggle reset twice In-reply-to: <20190113154028.GB4635@lunn.ch> Date: Sun, 13 Jan 2019 20:42:39 +0200 Message-ID: <87o98kv1pc.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 Sun, Jan 13 2019, Andrew Lunn wrote: >> Another look at this comment made me realize that we need comphy >> initialization support in the kernel for PCIe reset to work correctly. >> >> The workaround that this patch proposes will not solve the problem for >> v5.0, since the GPIO get_direction patch will only appear in v5.1. > > You could ask for it to be applied to v5.0 since a real fix depends on > it. > > We have a bit of a balancing act to sort out. The revert will fix > Macchiatobin. But i assume it breaks some other platforms which just > started to work. Ideally we want the best of both worlds. So maybe > getting the GPIO change into stable is the correct thing to do? Support for that other board (Clearfog GT-8K) has only been introduced in v5.0. The kernel never supported PCIe on that platform. So there is no regression for CF GT-8K like there is for the Macchiatobin. The issue is quite easy to deal with at the U-Boot level even for v5.0. The workaround that this patch suggests is pretty ugly, as you noted. I think we can live with no PCIe reset support in the kernel for another release or two. 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 -