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=-10.8 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 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 A0D08C433E0 for ; Mon, 15 Mar 2021 21:52:34 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 4B14F64F07 for ; Mon, 15 Mar 2021 21:52:34 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232194AbhCOVwB (ORCPT ); Mon, 15 Mar 2021 17:52:01 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:34368 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229696AbhCOVv3 (ORCPT ); Mon, 15 Mar 2021 17:51:29 -0400 Received: from ssl.serverraum.org (ssl.serverraum.org [IPv6:2a01:4f8:151:8464::1:2]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id EB5EDC06174A; Mon, 15 Mar 2021 14:51:28 -0700 (PDT) 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 67E1822234; Mon, 15 Mar 2021 22:51:25 +0100 (CET) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=walle.cc; s=mail2016061301; t=1615845086; 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=qbz18nJ52fhKTcYvqVifixwv65SjhEo6nJ/z7ymJrV0=; b=QwgxxdZ63fdHtC0poTGN4eZlhN+ambTQ2Veti9bfvBQiBvBN4wyHDyw98IiAV+zGHVswPe ZFfhSphnd25WlsBmUEnm2dr6IAYOwvfNphhQE3BGLJITeeJhHD9didZHjZ3QX0+4gBj81o zAb+CBIyYdXWbq3M9hCd9sZFDDi+cuE= MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII; format=flowed Content-Transfer-Encoding: 7bit Date: Mon, 15 Mar 2021 22:51:25 +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: <20210201222010.GA31234@bjorn-Precision-5520> References: <20210201222010.GA31234@bjorn-Precision-5520> User-Agent: Roundcube Webmail/1.4.11 Message-ID: X-Sender: michael@walle.cc Precedence: bulk List-ID: X-Mailing-List: linux-pci@vger.kernel.org Am 2021-02-01 23:20, schrieb Bjorn Helgaas: > On Mon, Feb 01, 2021 at 08:49:16PM +0100, Michael Walle wrote: >> 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? > > Thanks for the reminder. I was thinking this morning that I need to > get back to this. I'm trying to convince myself that doing this > wouldn't break the problem fixed by 755528c860b0 ("Ignore disabled ROM > resources at setup"). So far I haven't quite succeeded. ping #2 ;) -michael