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=-5.2 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED,USER_AGENT_SANE_2 autolearn=no 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 37B57C2D0A3 for ; Thu, 29 Oct 2020 22:06:50 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id D175A20838 for ; Thu, 29 Oct 2020 22:06:49 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1725562AbgJ2WGs (ORCPT ); Thu, 29 Oct 2020 18:06:48 -0400 Received: from mslow2.mail.gandi.net ([217.70.178.242]:51922 "EHLO mslow2.mail.gandi.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725372AbgJ2WGs (ORCPT ); Thu, 29 Oct 2020 18:06:48 -0400 Received: from relay1-d.mail.gandi.net (unknown [217.70.183.193]) by mslow2.mail.gandi.net (Postfix) with ESMTP id 6A62F3A1C1D for ; Thu, 29 Oct 2020 21:54:33 +0000 (UTC) X-Originating-IP: 83.193.246.53 Received: from windsurf.home (lfbn-bay-1-165-53.w83-193.abo.wanadoo.fr [83.193.246.53]) (Authenticated sender: thomas.petazzoni@bootlin.com) by relay1-d.mail.gandi.net (Postfix) with ESMTPSA id C5E2A240009; Thu, 29 Oct 2020 21:54:10 +0000 (UTC) Date: Thu, 29 Oct 2020 22:54:09 +0100 From: Thomas Petazzoni To: Bjorn Helgaas Cc: Toke =?UTF-8?B?SMO4aWxhbmQtSsO4cmdlbnNlbg==?= , Pali =?UTF-8?B?Um9ow6Fy?= , vtolkm@gmail.com, linux-pci@vger.kernel.org, linux-arm-kernel@lists.infradead.org, Rob Herring , Ilias Apalodimas , Marek =?UTF-8?B?QmVow7pu?= , Jason Cooper Subject: Re: PCI trouble on mvebu (Turris Omnia) Message-ID: <20201029225409.2accead3@windsurf.home> In-Reply-To: <20201029193022.GA476048@bjorn-Precision-5520> References: <871rhhmgkq.fsf@toke.dk> <20201029193022.GA476048@bjorn-Precision-5520> Organization: Bootlin X-Mailer: Claws Mail 3.17.7 (GTK+ 2.24.32; x86_64-redhat-linux-gnu) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-pci@vger.kernel.org Hello, On Thu, 29 Oct 2020 14:30:22 -0500 Bjorn Helgaas wrote: > We could quirk these NICs to avoid the retrain, but since aardvark and > mvebu have no obvious connection and WLE200/WLE900 and MT76 have no > obvious connection, I doubt there's a simple hardware defect that > explains all these. aardvark and mvebu have one very strong connection: they are the only two drivers making use of the PCI Bridge emulation logic in drivers/pci/pci-bridge-emul.c: drivers/pci$ git grep pci-bridge-emul akefile:obj-$(CONFIG_PCI_BRIDGE_EMUL) += pci-bridge-emul.o controller/pci-aardvark.c:#include "../pci-bridge-emul.h" controller/pci-mvebu.c:#include "../pci-bridge-emul.h" pci-bridge-emul.c:#include "pci-bridge-emul.h" I haven't read the whole thread, but it is important to keep in mind that on those two platforms, the PCI Bridge seen by Linux is *not* a real HW bridge. It is faked by the the pci-bridge-emul code. So if this code has defects/bugs in how it emulates a PCI Bridge behavior, you might see weird things. Best regards, Thomas -- Thomas Petazzoni, CTO, Bootlin Embedded Linux and Kernel engineering https://bootlin.com 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=-5.3 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_SANE_2 autolearn=no 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 45DE9C2D0A3 for ; Thu, 29 Oct 2020 21:55:05 +0000 (UTC) Received: from merlin.infradead.org (merlin.infradead.org [205.233.59.134]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id ACE412075E for ; Thu, 29 Oct 2020 21:55:04 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=lists.infradead.org header.i=@lists.infradead.org header.b="Hajli1qG" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org ACE412075E Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=bootlin.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=merlin.20170209; h=Sender:Content-Transfer-Encoding: Content-Type:Cc:List-Subscribe:List-Help:List-Post:List-Archive: List-Unsubscribe:List-Id:MIME-Version:References:In-Reply-To:Message-ID: Subject:To:From:Date:Reply-To:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=+Lmva1Vt0dBxOr/tuob8ZO4nmgyYpZmGEh4Fv+hmaR8=; b=Hajli1qGVtpg+IMSpBSODi/se lhVua9+qTaK1rc2nsgRncGW6W4+D1Bh0Oc2p3DcAeYOXcqGCBirgyYy0k9ZcWjFytNFZPxqOYR2x5 qX3b2vNBUbYzzch53IJMHV2nGFU0ai8YIs7PylThLSSI+Jey6xKPiPw80gsdMSuSCQNgsfPASKOcx eBsKB47LQwcv1dKdX0IL7nq7CzYew23UB+30Amu8cynz2ZFifxZeEjb8fixOQNfb3UoPWmL3hI4s3 5GL5kszjgFiFbsb2BA1vYtVCcMnSsScSVpVbT+84T9/0HuRK8Sa+ZMN0UO3ihdW9NSjuLh9GKp4dT ceuc4YRwA==; Received: from localhost ([::1] helo=merlin.infradead.org) by merlin.infradead.org with esmtp (Exim 4.92.3 #3 (Red Hat Linux)) id 1kYFsC-0000js-Og; Thu, 29 Oct 2020 21:54:20 +0000 Received: from relay1-d.mail.gandi.net ([217.70.183.193]) by merlin.infradead.org with esmtps (Exim 4.92.3 #3 (Red Hat Linux)) id 1kYFs9-0000jK-HD for linux-arm-kernel@lists.infradead.org; Thu, 29 Oct 2020 21:54:18 +0000 X-Originating-IP: 83.193.246.53 Received: from windsurf.home (lfbn-bay-1-165-53.w83-193.abo.wanadoo.fr [83.193.246.53]) (Authenticated sender: thomas.petazzoni@bootlin.com) by relay1-d.mail.gandi.net (Postfix) with ESMTPSA id C5E2A240009; Thu, 29 Oct 2020 21:54:10 +0000 (UTC) Date: Thu, 29 Oct 2020 22:54:09 +0100 From: Thomas Petazzoni To: Bjorn Helgaas Subject: Re: PCI trouble on mvebu (Turris Omnia) Message-ID: <20201029225409.2accead3@windsurf.home> In-Reply-To: <20201029193022.GA476048@bjorn-Precision-5520> References: <871rhhmgkq.fsf@toke.dk> <20201029193022.GA476048@bjorn-Precision-5520> Organization: Bootlin X-Mailer: Claws Mail 3.17.7 (GTK+ 2.24.32; x86_64-redhat-linux-gnu) MIME-Version: 1.0 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20201029_175417_678548_486B1D7E X-CRM114-Status: UNSURE ( 9.75 ) X-CRM114-Notice: Please train this message. X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Rob Herring , Ilias Apalodimas , Jason Cooper , Pali =?UTF-8?B?Um9ow6Fy?= , Toke =?UTF-8?B?SMO4aWxhbmQtSsO4cmdlbnNlbg==?= , Marek =?UTF-8?B?QmVow7pu?= , linux-pci@vger.kernel.org, vtolkm@gmail.com, linux-arm-kernel@lists.infradead.org Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org Hello, On Thu, 29 Oct 2020 14:30:22 -0500 Bjorn Helgaas wrote: > We could quirk these NICs to avoid the retrain, but since aardvark and > mvebu have no obvious connection and WLE200/WLE900 and MT76 have no > obvious connection, I doubt there's a simple hardware defect that > explains all these. aardvark and mvebu have one very strong connection: they are the only two drivers making use of the PCI Bridge emulation logic in drivers/pci/pci-bridge-emul.c: drivers/pci$ git grep pci-bridge-emul akefile:obj-$(CONFIG_PCI_BRIDGE_EMUL) += pci-bridge-emul.o controller/pci-aardvark.c:#include "../pci-bridge-emul.h" controller/pci-mvebu.c:#include "../pci-bridge-emul.h" pci-bridge-emul.c:#include "pci-bridge-emul.h" I haven't read the whole thread, but it is important to keep in mind that on those two platforms, the PCI Bridge seen by Linux is *not* a real HW bridge. It is faked by the the pci-bridge-emul code. So if this code has defects/bugs in how it emulates a PCI Bridge behavior, you might see weird things. Best regards, Thomas -- Thomas Petazzoni, CTO, Bootlin Embedded Linux and Kernel engineering https://bootlin.com _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel