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=-10.7 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED autolearn=unavailable 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 6C59CC433E6 for ; Mon, 1 Feb 2021 19:57:13 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 314AA64EBF for ; Mon, 1 Feb 2021 19:57:13 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232488AbhBAT46 (ORCPT ); Mon, 1 Feb 2021 14:56:58 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:41316 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232650AbhBATuI (ORCPT ); Mon, 1 Feb 2021 14:50:08 -0500 Received: from ssl.serverraum.org (ssl.serverraum.org [IPv6:2a01:4f8:151:8464::1:2]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 1563DC061573; Mon, 1 Feb 2021 11:49:19 -0800 (PST) Received: from ssl.serverraum.org (web.serverraum.org [172.16.0.2]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ssl.serverraum.org (Postfix) with ESMTPSA id 28E9322F99; Mon, 1 Feb 2021 20:49:16 +0100 (CET) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=walle.cc; s=mail2016061301; t=1612208956; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=ZwS7M5DVuVgIp79W7J+1nUCnHx61grFZNqdoFSservc=; b=jfjC5UQX2h4RSHu6T7RZ/nYdN9hdMuqbKuhhMXE6S8LYTxZZP00hnKmVKgGqCUfBuK8MCs 1o1ZA0YAmytg9kG4IgWDdQX410Y3GNYy3T7LHzDEB30OZLX0Ty5u+9NdWGZDFzu6VdV1Yy 2405m45kM0WBRI7g5S69bUv9gdTmkzI= MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII; format=flowed Content-Transfer-Encoding: 7bit Date: Mon, 01 Feb 2021 20:49:16 +0100 From: Michael Walle To: Bjorn Helgaas Cc: linux-pci@vger.kernel.org, linux-kernel@vger.kernel.org, intel-wired-lan@lists.osuosl.org, Bjorn Helgaas , Jesse Brandeburg , Tony Nguyen , Paul Menzel Subject: Re: [PATCH v2] PCI: Fix Intel i210 by avoiding overlapping of BARs In-Reply-To: <2477c66eafbd97207693b83b60fa0a3c@walle.cc> References: <20210115235721.GA1862880@bjorn-Precision-5520> <2477c66eafbd97207693b83b60fa0a3c@walle.cc> User-Agent: Roundcube Webmail/1.4.10 Message-ID: X-Sender: michael@walle.cc Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Bjorn, Am 2021-01-17 20:27, schrieb Michael Walle: > Am 2021-01-16 00:57, schrieb Bjorn Helgaas: >> On Wed, Jan 13, 2021 at 12:32:32AM +0100, Michael Walle wrote: >>> Am 2021-01-12 23:58, schrieb Bjorn Helgaas: >>> > On Sat, Jan 09, 2021 at 07:31:46PM +0100, Michael Walle wrote: >>> > > Am 2021-01-08 22:20, schrieb Bjorn Helgaas: >> >>> > > > 3) If the Intel i210 is defective in how it handles an Expansion ROM >>> > > > that overlaps another BAR, a quirk might be the right fix. But my >>> > > > guess is the device is working correctly per spec and there's >>> > > > something wrong in how firmware/Linux is assigning things. That would >>> > > > mean we need a more generic fix that's not a quirk and not tied to the >>> > > > Intel i210. >>> > > >>> > > Agreed, but as you already stated (and I've also found that in >>> > > the PCI spec) the Expansion ROM address decoder can be shared by >>> > > the other BARs and it shouldn't matter as long as the ExpROM BAR >>> > > is disabled, which is the case here. >>> > >>> > My point is just that if this could theoretically affect devices >>> > other than the i210, the fix should not be an i210-specific quirk. >>> > I'll assume this is a general problem and wait for a generic PCI >>> > core solution unless it's i210-specific. >>> >>> I guess the culprit here is that linux skips the programming of the >>> BAR because of some broken Matrox card. That should have been a >>> quirk instead, right? But I don't know if we want to change that, do >>> we? How many other cards depend on that? >> >> Oh, right. There's definitely some complicated history there that >> makes me a little scared to change things. But it's also unfortunate >> if we have to pile quirks on top of quirks. >> >>> And still, how do we find out that the i210 is behaving correctly? >>> In my opinion it is clearly not. You can change the ExpROM BAR value >>> during runtime and it will start working (while keeping it >>> disabled). Am I missing something here? >> >> I agree; if the ROM BAR is disabled, I don't think it should matter at >> all what it contains, so this does look like an i210 defect. >> >> Would you mind trying the patch below? It should update the ROM BAR >> value even when it is disabled. With the current pci_enable_rom() >> code that doesn't rely on the value read from the BAR, I *think* this >> should be safe even on the Matrox and similar devices. > > Your patch will fix my issue: > > Tested-by: Michael Walle any news on this? -michael