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=-0.6 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS 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 8C629C3F68F for ; Wed, 29 Jan 2020 01:32:21 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 5FFD224686 for ; Wed, 29 Jan 2020 01:32:21 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="DAqfA2Q2" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726389AbgA2BcU (ORCPT ); Tue, 28 Jan 2020 20:32:20 -0500 Received: from mail-io1-f67.google.com ([209.85.166.67]:40567 "EHLO mail-io1-f67.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726363AbgA2BcU (ORCPT ); Tue, 28 Jan 2020 20:32:20 -0500 Received: by mail-io1-f67.google.com with SMTP id x1so16730938iop.7; Tue, 28 Jan 2020 17:32:20 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=OINYauu/FMq3XOWWth+EZlBMMQYby1FB2lj9pkceckU=; b=DAqfA2Q2IZOL2p+2+8mDc/eHucTMeIe195YcmRbXqZPEQ1BUrWJYhTKOc45wFCj9ws qbFljs2PdS4QccbtjDeRr/7+YuC89DjKx7uQZF1J2oq7VpqynyNalFg6ZtDfK+7RuS3R md1a3GGnY9KMsn7gylymfHEXOE1Ny6CEuhGalSwdeX1bajGEraP7Kl15ewD3IypqbYpA epvg5KOjAvhjqPuPbopUTfxjXQCHv6uc2O84Bu3Sh5nxujCgLg21xyUkSJoEjgbWMNLE IHTLPOOU7viAze8jUrPhhh6niIsEKPJB8qwKXsqEyqIgAiUdtV70gykK/66fJQVHHmJA Yx6A== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=OINYauu/FMq3XOWWth+EZlBMMQYby1FB2lj9pkceckU=; b=VhPVF/ePIVbfwYR8PzLEXomGgBIqHttNQ0Xk5qjDn2oVxIH9l25rgZH0jDh7taW9P2 EXzU9OFEn3XJ0EwrkBdNhjbEVEyxTgfzdaRlUdPcp9LPP4WMkSyhIDl/ah1vCwpTF7SW BPTKVN0fiiO2Bw0YCKShF/zqVaW24s8rnfvGuGn6oDrFUroNBhQqjj/m0iCy1W77Kuos mEf2+40qgXgqL7O3o7jmnzInMbNtRTr1DBEZbpSRg7Re5l9dDDLu2CP9kK6qvhyYZzJd u6SSio9Nj/trrWQTFdTVMj1YjH9bvKZAiICcjrExzdZcADY0YiRBtc0t35E9GLbUtkWf HMkQ== X-Gm-Message-State: APjAAAW8dJK5xzpq9WevC3rOty6tvdK4FdI4QRnd0ezWAAx5HK1zJuqN jEoNohoIP13CCI+yJCb8c8h4EiJvI8dAJnntFy8= X-Google-Smtp-Source: APXvYqyjDYSrA853V/qdJsqhISgAYNfOdiEApwa11SxBrKEwiNeyKkuwVJIZChAAe9De33mzBsnHuRnoewo1Vkt9BBY= X-Received: by 2002:a02:3508:: with SMTP id k8mr15363989jaa.114.1580261539263; Tue, 28 Jan 2020 17:32:19 -0800 (PST) MIME-Version: 1.0 References: <20200124144248.11719-1-yu.c.chen@intel.com> <20200124193142.GA33298@google.com> In-Reply-To: <20200124193142.GA33298@google.com> From: Dan Williams Date: Tue, 28 Jan 2020 17:32:07 -0800 Message-ID: Subject: Re: [PATCH][RFC] PCI: Add "pci=blacklist_dev=" parameter to blacklist specific devices To: Bjorn Helgaas Cc: Chen Yu , linux-pci@vger.kernel.org, Jonathan Corbet , linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org, Len Brown , "Rafael J. Wysocki" Content-Type: text/plain; charset="UTF-8" Sender: linux-pci-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-pci@vger.kernel.org On Fri, Jan 24, 2020 at 1:01 PM Bjorn Helgaas wrote: > > On Fri, Jan 24, 2020 at 10:42:48PM +0800, Chen Yu wrote: > > It was found that on some platforms the bogus pci device might bring > > troubles to the system. For example, on a MacBookPro the system could > > not be power off or suspended due to internal pci resource confliction > > between bogus pci device and [io 0x1804]. Another case is that, once > > resumed from hibernation on a VM, the pci config space of a pci device > > is corrupt. > > > > To narrow down and benefit future debugging for such kind of issues, > > introduce the command line blacklist_dev=> to blacklist > > such pci devices thus they will not be scanned thus not visible after > > bootup. For example, > > > > pci.blacklist_dev=8086:293e > > > > forbid the audio device to be exposed to the OS. > > I'm not really a fan of this. I'd rather see some details about what > the problem is so we can actually fix it. > > Ignoring the device doesn't mean the device is removed or even > inactive. It may still be consuming address space that we need to > avoid. > > Can you point us to bug reports about the issues you mentioned? I'm not sure which issues Chen Yu is referring to, but a proposal like has come up before [1], and didn't go anywhere. I think this is useful to people doing new / pre-release hardware bring up, but it's unlikely that such hardware makes it into a production to make this feature useful upstream. Hardware bring-up efforts can just use local hacks to workaround problems, if broken hardware actually makes it into production it needs precise quirks to be developed/applied. [1]: http://lore.kernel.org/r/1506544822-2632-2-git-send-email-jonathan.derrick@intel.com