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=-3.8 required=3.0 tests=BAYES_00,DKIM_INVALID, DKIM_SIGNED,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 B059BC433DF for ; Mon, 3 Aug 2020 06:57:02 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 861C1206E9 for ; Mon, 3 Aug 2020 06:57:02 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b="Imiqwh2w" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726707AbgHCG5C (ORCPT ); Mon, 3 Aug 2020 02:57:02 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:47810 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726224AbgHCG5C (ORCPT ); Mon, 3 Aug 2020 02:57:02 -0400 Received: from casper.infradead.org (casper.infradead.org [IPv6:2001:8b0:10b:1236::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id DFBB4C06174A; Sun, 2 Aug 2020 23:57:01 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=casper.20170209; h=In-Reply-To:Content-Type:MIME-Version: References:Message-ID:Subject:Cc:To:From:Date:Sender:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description; bh=S81Y7/E/1KRByHOMFTAO1WQMOll7HWoP+pv/fCo/3sI=; b=Imiqwh2wh6gfO95HVgGWdIpJ7R qFqJDaURIpsOiDpUCq2k3ILdHp9/G64PbhflfbfwXUHR3YCqdMM2JIr5p2HV5QlEFNjYcibq1cAwB k5jcDFqNUiYh1ErghhsIpsN5baKyFw50AsjkOnyh0RkcQvG4I/FuQV4i+K4smxUlt0gQ8ZINX4zk1 zqYZrKBpxdTsr3nucjd2JPKqfEkufPqh/aFaSwGu2mFtFylC2a36pyZdPfsQXEbP1+7In5Kkj2kTD iIuAdnnH0jCfMh5vNRvgFzTjztCURqfBsmyFjwViAe1IQB++yIvaVvpqhNNNwV/B+lmZFzbHjUNTv QTu3Qcmg==; Received: from hch by casper.infradead.org with local (Exim 4.92.3 #3 (Red Hat Linux)) id 1k2UOb-0005Zd-6v; Mon, 03 Aug 2020 06:56:29 +0000 Date: Mon, 3 Aug 2020 07:56:29 +0100 From: Christoph Hellwig To: Bjorn Helgaas Cc: Borislav Petkov , Saheed Bolarinwa , trix@redhat.com, Kalle Valo , "David S. Miller" , Jakub Kicinski , Wolfgang Grandegger , Marc Kleine-Budde , Miquel Raynal , Richard Weinberger , Vignesh Raghavendra , Joerg Roedel , bjorn@helgaas.com, skhan@linuxfoundation.org, linux-kernel-mentees@lists.linuxfoundation.org, linux-pci@vger.kernel.org, linux-kernel@vger.kernel.org, linux-wireless@vger.kernel.org, netdev@vger.kernel.org, linux-mtd@lists.infradead.org, iommu@lists.linux-foundation.org, linux-rdma@vger.kernel.org, linux-ide@vger.kernel.org, linux-i2c@vger.kernel.org, linux-hwmon@vger.kernel.org, dri-devel@lists.freedesktop.org, intel-gfx@lists.freedesktop.org, linux-gpio@vger.kernel.org, linux-fpga@vger.kernel.org, linux-edac@vger.kernel.org, dmaengine@vger.kernel.org, linux-crypto@vger.kernel.org, linux-atm-general@lists.sourceforge.net Subject: Re: [RFC PATCH 00/17] Drop uses of pci_read_config_*() return value Message-ID: <20200803065629.GA19534@infradead.org> References: <20200802184648.GA23190@nazgul.tnic> <20200802191406.GA248232@bjorn-Precision-5520> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20200802191406.GA248232@bjorn-Precision-5520> X-SRS-Rewrite: SMTP reverse-path rewritten from by casper.infradead.org. See http://www.infradead.org/rpr.html Sender: dmaengine-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: dmaengine@vger.kernel.org On Sun, Aug 02, 2020 at 02:14:06PM -0500, Bjorn Helgaas wrote: > But what guarantees that a PCI config register cannot contain ~0? > If there's something about that in the spec I'd love to know where it > is because it would simplify a lot of things. There isn't. An we even have cases like the NVMe controller memory buffer and persistent memory region, which are BARs that store abritrary values for later retreival, so it can't. (now those features have a major issue with error detection, but that is another issue) 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=-4.0 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 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 5C176C433DF for ; Mon, 3 Aug 2020 06:57:05 +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 27A2C2068F for ; Mon, 3 Aug 2020 06:57:05 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=lists.infradead.org header.i=@lists.infradead.org header.b="TLiyvyqJ"; dkim=fail reason="signature verification failed" (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b="Imiqwh2w" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 27A2C2068F Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=infradead.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-mtd-bounces+linux-mtd=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:In-Reply-To:MIME-Version:References: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=Q9ct0iSBXe5WAh0dm9j9c3ccTenO930Qt6nOtLrU/5o=; b=TLiyvyqJoAMNE0FXts/c1lJbV 6tWqZdeOmsK3s3S3L5j8Cy3nJBCNQm0uzlUosrbClXlanpcodQU9dgzcFsjLp/05FoLdfRxy5mV5P rrKFYeLu11wsYEXHy3d4s7MK23es/710Ah7OJocFSYhsaBINNl+cYrBtngPO79BX9M+iyy5ZzLmbf /dpCox8bua/y72g6gvI+yzx97WyDy645te3FjrnFbfpFgOcgu63gnxHS1sJh7o+KmllMiK31ai0HW jReaRLAnWWlzCW7ck+ECps4zVuT/dbhW11fa9bFowBw4w3yGs1NXQSodwToHPiSpRzJHDgxM/KWEE 19QQgzoxQ==; Received: from localhost ([::1] helo=merlin.infradead.org) by merlin.infradead.org with esmtp (Exim 4.92.3 #3 (Red Hat Linux)) id 1k2UOj-0004Vc-L9; Mon, 03 Aug 2020 06:56:37 +0000 Received: from casper.infradead.org ([2001:8b0:10b:1236::1]) by merlin.infradead.org with esmtps (Exim 4.92.3 #3 (Red Hat Linux)) id 1k2UOh-0004V8-PW for linux-mtd@merlin.infradead.org; Mon, 03 Aug 2020 06:56:35 +0000 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=casper.20170209; h=In-Reply-To:Content-Type:MIME-Version: References:Message-ID:Subject:Cc:To:From:Date:Sender:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description; bh=S81Y7/E/1KRByHOMFTAO1WQMOll7HWoP+pv/fCo/3sI=; b=Imiqwh2wh6gfO95HVgGWdIpJ7R qFqJDaURIpsOiDpUCq2k3ILdHp9/G64PbhflfbfwXUHR3YCqdMM2JIr5p2HV5QlEFNjYcibq1cAwB k5jcDFqNUiYh1ErghhsIpsN5baKyFw50AsjkOnyh0RkcQvG4I/FuQV4i+K4smxUlt0gQ8ZINX4zk1 zqYZrKBpxdTsr3nucjd2JPKqfEkufPqh/aFaSwGu2mFtFylC2a36pyZdPfsQXEbP1+7In5Kkj2kTD iIuAdnnH0jCfMh5vNRvgFzTjztCURqfBsmyFjwViAe1IQB++yIvaVvpqhNNNwV/B+lmZFzbHjUNTv QTu3Qcmg==; Received: from hch by casper.infradead.org with local (Exim 4.92.3 #3 (Red Hat Linux)) id 1k2UOb-0005Zd-6v; Mon, 03 Aug 2020 06:56:29 +0000 Date: Mon, 3 Aug 2020 07:56:29 +0100 From: Christoph Hellwig To: Bjorn Helgaas Subject: Re: [RFC PATCH 00/17] Drop uses of pci_read_config_*() return value Message-ID: <20200803065629.GA19534@infradead.org> References: <20200802184648.GA23190@nazgul.tnic> <20200802191406.GA248232@bjorn-Precision-5520> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <20200802191406.GA248232@bjorn-Precision-5520> X-SRS-Rewrite: SMTP reverse-path rewritten from by casper.infradead.org. See http://www.infradead.org/rpr.html X-BeenThere: linux-mtd@lists.infradead.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Linux MTD discussion mailing list List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Vignesh Raghavendra , linux-pci@vger.kernel.org, linux-fpga@vger.kernel.org, dri-devel@lists.freedesktop.org, linux-ide@vger.kernel.org, linux-mtd@lists.infradead.org, linux-i2c@vger.kernel.org, Miquel Raynal , linux-rdma@vger.kernel.org, Richard Weinberger , Joerg Roedel , linux-atm-general@lists.sourceforge.net, trix@redhat.com, Jakub Kicinski , linux-kernel-mentees@lists.linuxfoundation.org, Wolfgang Grandegger , intel-gfx@lists.freedesktop.org, linux-gpio@vger.kernel.org, Borislav Petkov , skhan@linuxfoundation.org, bjorn@helgaas.com, Kalle Valo , linux-edac@vger.kernel.org, linux-hwmon@vger.kernel.org, Saheed Bolarinwa , linux-wireless@vger.kernel.org, linux-kernel@vger.kernel.org, iommu@lists.linux-foundation.org, linux-crypto@vger.kernel.org, netdev@vger.kernel.org, dmaengine@vger.kernel.org, Marc Kleine-Budde , "David S. Miller" Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-mtd" Errors-To: linux-mtd-bounces+linux-mtd=archiver.kernel.org@lists.infradead.org On Sun, Aug 02, 2020 at 02:14:06PM -0500, Bjorn Helgaas wrote: > But what guarantees that a PCI config register cannot contain ~0? > If there's something about that in the spec I'd love to know where it > is because it would simplify a lot of things. There isn't. An we even have cases like the NVMe controller memory buffer and persistent memory region, which are BARs that store abritrary values for later retreival, so it can't. (now those features have a major issue with error detection, but that is another issue) ______________________________________________________ Linux MTD discussion mailing list http://lists.infradead.org/mailman/listinfo/linux-mtd/ 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=-3.8 required=3.0 tests=BAYES_00,DKIM_INVALID, DKIM_SIGNED,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE, SPF_PASS,URIBL_BLOCKED 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 44B46C433E8 for ; Mon, 3 Aug 2020 06:57:04 +0000 (UTC) Received: from silver.osuosl.org (smtp3.osuosl.org [140.211.166.136]) (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 0F37D206F6 for ; Mon, 3 Aug 2020 06:57:03 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b="Imiqwh2w" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 0F37D206F6 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=infradead.org Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=iommu-bounces@lists.linux-foundation.org Received: from localhost (localhost [127.0.0.1]) by silver.osuosl.org (Postfix) with ESMTP id 589182036D; Mon, 3 Aug 2020 06:57:04 +0000 (UTC) X-Virus-Scanned: amavisd-new at osuosl.org Received: from silver.osuosl.org ([127.0.0.1]) by localhost (.osuosl.org [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id QivUHhva+Shm; Mon, 3 Aug 2020 06:57:03 +0000 (UTC) Received: from lists.linuxfoundation.org (lf-lists.osuosl.org [140.211.9.56]) by silver.osuosl.org (Postfix) with ESMTP id 6AE04203BA; Mon, 3 Aug 2020 06:57:03 +0000 (UTC) Received: from lf-lists.osuosl.org (localhost [127.0.0.1]) by lists.linuxfoundation.org (Postfix) with ESMTP id 569B1C0050; Mon, 3 Aug 2020 06:57:03 +0000 (UTC) Received: from fraxinus.osuosl.org (smtp4.osuosl.org [140.211.166.137]) by lists.linuxfoundation.org (Postfix) with ESMTP id 4D7F6C004C; Mon, 3 Aug 2020 06:57:01 +0000 (UTC) Received: from localhost (localhost [127.0.0.1]) by fraxinus.osuosl.org (Postfix) with ESMTP id 37FA185522; Mon, 3 Aug 2020 06:57:01 +0000 (UTC) X-Virus-Scanned: amavisd-new at osuosl.org Received: from fraxinus.osuosl.org ([127.0.0.1]) by localhost (.osuosl.org [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id ZTaJ1kClqTte; Mon, 3 Aug 2020 06:57:00 +0000 (UTC) X-Greylist: from auto-whitelisted by SQLgrey-1.7.6 X-Greylist: from auto-whitelisted by SQLgrey-1.7.6 Received: from casper.infradead.org (casper.infradead.org [90.155.50.34]) by fraxinus.osuosl.org (Postfix) with ESMTPS id 4D1CB854E5; Mon, 3 Aug 2020 06:57:00 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=casper.20170209; h=In-Reply-To:Content-Type:MIME-Version: References:Message-ID:Subject:Cc:To:From:Date:Sender:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description; bh=S81Y7/E/1KRByHOMFTAO1WQMOll7HWoP+pv/fCo/3sI=; b=Imiqwh2wh6gfO95HVgGWdIpJ7R qFqJDaURIpsOiDpUCq2k3ILdHp9/G64PbhflfbfwXUHR3YCqdMM2JIr5p2HV5QlEFNjYcibq1cAwB k5jcDFqNUiYh1ErghhsIpsN5baKyFw50AsjkOnyh0RkcQvG4I/FuQV4i+K4smxUlt0gQ8ZINX4zk1 zqYZrKBpxdTsr3nucjd2JPKqfEkufPqh/aFaSwGu2mFtFylC2a36pyZdPfsQXEbP1+7In5Kkj2kTD iIuAdnnH0jCfMh5vNRvgFzTjztCURqfBsmyFjwViAe1IQB++yIvaVvpqhNNNwV/B+lmZFzbHjUNTv QTu3Qcmg==; Received: from hch by casper.infradead.org with local (Exim 4.92.3 #3 (Red Hat Linux)) id 1k2UOb-0005Zd-6v; Mon, 03 Aug 2020 06:56:29 +0000 Date: Mon, 3 Aug 2020 07:56:29 +0100 From: Christoph Hellwig To: Bjorn Helgaas Subject: Re: [RFC PATCH 00/17] Drop uses of pci_read_config_*() return value Message-ID: <20200803065629.GA19534@infradead.org> References: <20200802184648.GA23190@nazgul.tnic> <20200802191406.GA248232@bjorn-Precision-5520> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <20200802191406.GA248232@bjorn-Precision-5520> X-SRS-Rewrite: SMTP reverse-path rewritten from by casper.infradead.org. See http://www.infradead.org/rpr.html Cc: Vignesh Raghavendra , linux-pci@vger.kernel.org, linux-fpga@vger.kernel.org, dri-devel@lists.freedesktop.org, linux-ide@vger.kernel.org, linux-mtd@lists.infradead.org, linux-i2c@vger.kernel.org, Miquel Raynal , linux-rdma@vger.kernel.org, Richard Weinberger , linux-atm-general@lists.sourceforge.net, trix@redhat.com, Jakub Kicinski , linux-kernel-mentees@lists.linuxfoundation.org, Wolfgang Grandegger , intel-gfx@lists.freedesktop.org, linux-gpio@vger.kernel.org, Borislav Petkov , skhan@linuxfoundation.org, bjorn@helgaas.com, Kalle Valo , linux-edac@vger.kernel.org, linux-hwmon@vger.kernel.org, Saheed Bolarinwa , linux-wireless@vger.kernel.org, linux-kernel@vger.kernel.org, iommu@lists.linux-foundation.org, linux-crypto@vger.kernel.org, netdev@vger.kernel.org, dmaengine@vger.kernel.org, Marc Kleine-Budde , "David S. Miller" X-BeenThere: iommu@lists.linux-foundation.org X-Mailman-Version: 2.1.15 Precedence: list List-Id: Development issues for Linux IOMMU support List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Errors-To: iommu-bounces@lists.linux-foundation.org Sender: "iommu" On Sun, Aug 02, 2020 at 02:14:06PM -0500, Bjorn Helgaas wrote: > But what guarantees that a PCI config register cannot contain ~0? > If there's something about that in the spec I'd love to know where it > is because it would simplify a lot of things. There isn't. An we even have cases like the NVMe controller memory buffer and persistent memory region, which are BARs that store abritrary values for later retreival, so it can't. (now those features have a major issue with error detection, but that is another issue) _______________________________________________ iommu mailing list iommu@lists.linux-foundation.org https://lists.linuxfoundation.org/mailman/listinfo/iommu 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=-3.8 required=3.0 tests=BAYES_00,DKIM_INVALID, DKIM_SIGNED,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE, SPF_PASS,URIBL_BLOCKED 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 ADED7C433E4 for ; Mon, 3 Aug 2020 06:57:03 +0000 (UTC) Received: from fraxinus.osuosl.org (smtp4.osuosl.org [140.211.166.137]) (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 805C42068F for ; Mon, 3 Aug 2020 06:57:03 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b="Imiqwh2w" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 805C42068F Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=infradead.org Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=linux-kernel-mentees-bounces@lists.linuxfoundation.org Received: from localhost (localhost [127.0.0.1]) by fraxinus.osuosl.org (Postfix) with ESMTP id 0D78885B94; Mon, 3 Aug 2020 06:57:04 +0000 (UTC) X-Virus-Scanned: amavisd-new at osuosl.org Received: from fraxinus.osuosl.org ([127.0.0.1]) by localhost (.osuosl.org [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id 9hZkNOjtTk8v; Mon, 3 Aug 2020 06:57:03 +0000 (UTC) Received: from lists.linuxfoundation.org (lf-lists.osuosl.org [140.211.9.56]) by fraxinus.osuosl.org (Postfix) with ESMTP id 9F0E3857D1; Mon, 3 Aug 2020 06:57:03 +0000 (UTC) Received: from lf-lists.osuosl.org (localhost [127.0.0.1]) by lists.linuxfoundation.org (Postfix) with ESMTP id 87E40C088E; Mon, 3 Aug 2020 06:57:03 +0000 (UTC) Received: from fraxinus.osuosl.org (smtp4.osuosl.org [140.211.166.137]) by lists.linuxfoundation.org (Postfix) with ESMTP id 4D7F6C004C; Mon, 3 Aug 2020 06:57:01 +0000 (UTC) Received: from localhost (localhost [127.0.0.1]) by fraxinus.osuosl.org (Postfix) with ESMTP id 37FA185522; Mon, 3 Aug 2020 06:57:01 +0000 (UTC) X-Virus-Scanned: amavisd-new at osuosl.org Received: from fraxinus.osuosl.org ([127.0.0.1]) by localhost (.osuosl.org [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id ZTaJ1kClqTte; Mon, 3 Aug 2020 06:57:00 +0000 (UTC) X-Greylist: from auto-whitelisted by SQLgrey-1.7.6 X-Greylist: from auto-whitelisted by SQLgrey-1.7.6 Received: from casper.infradead.org (casper.infradead.org [90.155.50.34]) by fraxinus.osuosl.org (Postfix) with ESMTPS id 4D1CB854E5; Mon, 3 Aug 2020 06:57:00 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=casper.20170209; h=In-Reply-To:Content-Type:MIME-Version: References:Message-ID:Subject:Cc:To:From:Date:Sender:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description; bh=S81Y7/E/1KRByHOMFTAO1WQMOll7HWoP+pv/fCo/3sI=; b=Imiqwh2wh6gfO95HVgGWdIpJ7R qFqJDaURIpsOiDpUCq2k3ILdHp9/G64PbhflfbfwXUHR3YCqdMM2JIr5p2HV5QlEFNjYcibq1cAwB k5jcDFqNUiYh1ErghhsIpsN5baKyFw50AsjkOnyh0RkcQvG4I/FuQV4i+K4smxUlt0gQ8ZINX4zk1 zqYZrKBpxdTsr3nucjd2JPKqfEkufPqh/aFaSwGu2mFtFylC2a36pyZdPfsQXEbP1+7In5Kkj2kTD iIuAdnnH0jCfMh5vNRvgFzTjztCURqfBsmyFjwViAe1IQB++yIvaVvpqhNNNwV/B+lmZFzbHjUNTv QTu3Qcmg==; Received: from hch by casper.infradead.org with local (Exim 4.92.3 #3 (Red Hat Linux)) id 1k2UOb-0005Zd-6v; Mon, 03 Aug 2020 06:56:29 +0000 Date: Mon, 3 Aug 2020 07:56:29 +0100 From: Christoph Hellwig To: Bjorn Helgaas Message-ID: <20200803065629.GA19534@infradead.org> References: <20200802184648.GA23190@nazgul.tnic> <20200802191406.GA248232@bjorn-Precision-5520> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <20200802191406.GA248232@bjorn-Precision-5520> X-SRS-Rewrite: SMTP reverse-path rewritten from by casper.infradead.org. See http://www.infradead.org/rpr.html Cc: Vignesh Raghavendra , linux-pci@vger.kernel.org, linux-fpga@vger.kernel.org, dri-devel@lists.freedesktop.org, linux-ide@vger.kernel.org, linux-mtd@lists.infradead.org, linux-i2c@vger.kernel.org, Miquel Raynal , linux-rdma@vger.kernel.org, Richard Weinberger , Joerg Roedel , linux-atm-general@lists.sourceforge.net, trix@redhat.com, Jakub Kicinski , linux-kernel-mentees@lists.linuxfoundation.org, Wolfgang Grandegger , intel-gfx@lists.freedesktop.org, linux-gpio@vger.kernel.org, Borislav Petkov , Kalle Valo , linux-edac@vger.kernel.org, linux-hwmon@vger.kernel.org, Saheed Bolarinwa , linux-wireless@vger.kernel.org, linux-kernel@vger.kernel.org, iommu@lists.linux-foundation.org, linux-crypto@vger.kernel.org, netdev@vger.kernel.org, dmaengine@vger.kernel.org, Marc Kleine-Budde , "David S. Miller" Subject: Re: [Linux-kernel-mentees] [RFC PATCH 00/17] Drop uses of pci_read_config_*() return value X-BeenThere: linux-kernel-mentees@lists.linuxfoundation.org X-Mailman-Version: 2.1.15 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Errors-To: linux-kernel-mentees-bounces@lists.linuxfoundation.org Sender: "Linux-kernel-mentees" On Sun, Aug 02, 2020 at 02:14:06PM -0500, Bjorn Helgaas wrote: > But what guarantees that a PCI config register cannot contain ~0? > If there's something about that in the spec I'd love to know where it > is because it would simplify a lot of things. There isn't. An we even have cases like the NVMe controller memory buffer and persistent memory region, which are BARs that store abritrary values for later retreival, so it can't. (now those features have a major issue with error detection, but that is another issue) _______________________________________________ Linux-kernel-mentees mailing list Linux-kernel-mentees@lists.linuxfoundation.org https://lists.linuxfoundation.org/mailman/listinfo/linux-kernel-mentees 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=-3.8 required=3.0 tests=BAYES_00,DKIM_INVALID, DKIM_SIGNED,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE, SPF_PASS,URIBL_BLOCKED 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 92A15C433DF for ; Mon, 3 Aug 2020 13:04:30 +0000 (UTC) Received: from gabe.freedesktop.org (gabe.freedesktop.org [131.252.210.177]) (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 6956F20738 for ; Mon, 3 Aug 2020 13:04:30 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b="Imiqwh2w" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 6956F20738 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=infradead.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=intel-gfx-bounces@lists.freedesktop.org Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id 9F7966E283; Mon, 3 Aug 2020 13:04:29 +0000 (UTC) Received: from casper.infradead.org (casper.infradead.org [IPv6:2001:8b0:10b:1236::1]) by gabe.freedesktop.org (Postfix) with ESMTPS id 2929E6E20F; Mon, 3 Aug 2020 06:57:02 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=casper.20170209; h=In-Reply-To:Content-Type:MIME-Version: References:Message-ID:Subject:Cc:To:From:Date:Sender:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description; bh=S81Y7/E/1KRByHOMFTAO1WQMOll7HWoP+pv/fCo/3sI=; b=Imiqwh2wh6gfO95HVgGWdIpJ7R qFqJDaURIpsOiDpUCq2k3ILdHp9/G64PbhflfbfwXUHR3YCqdMM2JIr5p2HV5QlEFNjYcibq1cAwB k5jcDFqNUiYh1ErghhsIpsN5baKyFw50AsjkOnyh0RkcQvG4I/FuQV4i+K4smxUlt0gQ8ZINX4zk1 zqYZrKBpxdTsr3nucjd2JPKqfEkufPqh/aFaSwGu2mFtFylC2a36pyZdPfsQXEbP1+7In5Kkj2kTD iIuAdnnH0jCfMh5vNRvgFzTjztCURqfBsmyFjwViAe1IQB++yIvaVvpqhNNNwV/B+lmZFzbHjUNTv QTu3Qcmg==; Received: from hch by casper.infradead.org with local (Exim 4.92.3 #3 (Red Hat Linux)) id 1k2UOb-0005Zd-6v; Mon, 03 Aug 2020 06:56:29 +0000 Date: Mon, 3 Aug 2020 07:56:29 +0100 From: Christoph Hellwig To: Bjorn Helgaas Message-ID: <20200803065629.GA19534@infradead.org> References: <20200802184648.GA23190@nazgul.tnic> <20200802191406.GA248232@bjorn-Precision-5520> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <20200802191406.GA248232@bjorn-Precision-5520> X-SRS-Rewrite: SMTP reverse-path rewritten from by casper.infradead.org. See http://www.infradead.org/rpr.html X-Mailman-Approved-At: Mon, 03 Aug 2020 13:04:28 +0000 Subject: Re: [Intel-gfx] [RFC PATCH 00/17] Drop uses of pci_read_config_*() return value X-BeenThere: intel-gfx@lists.freedesktop.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Intel graphics driver community testing & development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Vignesh Raghavendra , linux-pci@vger.kernel.org, linux-fpga@vger.kernel.org, dri-devel@lists.freedesktop.org, linux-ide@vger.kernel.org, linux-mtd@lists.infradead.org, linux-i2c@vger.kernel.org, Miquel Raynal , linux-rdma@vger.kernel.org, Richard Weinberger , Joerg Roedel , linux-atm-general@lists.sourceforge.net, trix@redhat.com, Jakub Kicinski , linux-kernel-mentees@lists.linuxfoundation.org, Wolfgang Grandegger , intel-gfx@lists.freedesktop.org, linux-gpio@vger.kernel.org, Borislav Petkov , skhan@linuxfoundation.org, bjorn@helgaas.com, Kalle Valo , linux-edac@vger.kernel.org, linux-hwmon@vger.kernel.org, Saheed Bolarinwa , linux-wireless@vger.kernel.org, linux-kernel@vger.kernel.org, iommu@lists.linux-foundation.org, linux-crypto@vger.kernel.org, netdev@vger.kernel.org, dmaengine@vger.kernel.org, Marc Kleine-Budde , "David S. Miller" Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Errors-To: intel-gfx-bounces@lists.freedesktop.org Sender: "Intel-gfx" On Sun, Aug 02, 2020 at 02:14:06PM -0500, Bjorn Helgaas wrote: > But what guarantees that a PCI config register cannot contain ~0? > If there's something about that in the spec I'd love to know where it > is because it would simplify a lot of things. There isn't. An we even have cases like the NVMe controller memory buffer and persistent memory region, which are BARs that store abritrary values for later retreival, so it can't. (now those features have a major issue with error detection, but that is another issue) _______________________________________________ Intel-gfx mailing list Intel-gfx@lists.freedesktop.org https://lists.freedesktop.org/mailman/listinfo/intel-gfx