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, NICE_REPLY_A,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_SANE_1 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 71B53C433DB for ; Fri, 5 Mar 2021 17:21:22 +0000 (UTC) Received: from desiato.infradead.org (desiato.infradead.org [90.155.92.199]) (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 EF00F6509F for ; Fri, 5 Mar 2021 17:21:21 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org EF00F6509F Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=marcan.st 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=desiato.20200630; h=Sender:Content-Type: Content-Transfer-Encoding:List-Subscribe:List-Help:List-Post:List-Archive: List-Unsubscribe:List-Id:In-Reply-To:MIME-Version:Date:Message-ID:From: References:Cc:To:Subject:Reply-To:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=GEwww+T/loj6QQ3gxZSGJLqmKbXGKW91focWZ2ZeUN4=; b=TZ7ZgKxWOyUo0QCDCz5KceVf+ RSStAmFdAhJWt0WigHlp+b3phqUhkbPtHWfhpJuBQU7/LW1wPZWrMhbyTzE0Gz7gta46aW3IGWf5I IIaCUCwSYqSN79EbhgVmDP1XrXo3MbnQqlLrOg8bUrgjSmfaI7gZ8GjREkfxOP0xORSsHQgA73xuS d8UpB9A++VDPRxm+ZP6fBpNXYNPK4LKw2u7J2rmZC0bG+sfQUvJAhHgaaG4VWEhVUxiP4F2WHYUWc yXStundWeUftVL334rlwCLWQvXMB+a03AwCPqbXF/NcoCru9cveyIAWwh5+Blu3CCNNgGEvgwxKEV 3dXIcE9SQ==; Received: from localhost ([::1] helo=desiato.infradead.org) by desiato.infradead.org with esmtp (Exim 4.94 #2 (Red Hat Linux)) id 1lIE74-00FlUQ-3Y; Fri, 05 Mar 2021 17:19:42 +0000 Received: from marcansoft.com ([212.63.210.85] helo=mail.marcansoft.com) by desiato.infradead.org with esmtps (Exim 4.94 #2 (Red Hat Linux)) id 1lIE6v-00FlT9-8q for linux-arm-kernel@lists.infradead.org; Fri, 05 Mar 2021 17:19:35 +0000 Received: from [127.0.0.1] (localhost [127.0.0.1]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256) (No client certificate requested) (Authenticated sender: marcan@marcan.st) by mail.marcansoft.com (Postfix) with ESMTPSA id 0610042037; Fri, 5 Mar 2021 17:19:25 +0000 (UTC) Subject: Re: [RFT PATCH v3 12/27] of/address: Add infrastructure to declare MMIO as non-posted To: Arnd Bergmann , Andy Shevchenko Cc: linux-arm Mailing List , Marc Zyngier , Rob Herring , Olof Johansson , Krzysztof Kozlowski , Mark Kettenis , Tony Lindgren , Mohamed Mediouni , Stan Skowronek , Alexander Graf , Will Deacon , Linus Walleij , Mark Rutland , Greg Kroah-Hartman , Jonathan Corbet , Catalin Marinas , Christoph Hellwig , "David S. Miller" , devicetree , "open list:SERIAL DRIVERS" , Linux Documentation List , Linux Samsung SOC , Linux-Arch , Linux Kernel Mailing List References: <20210304213902.83903-1-marcan@marcan.st> <20210304213902.83903-13-marcan@marcan.st> <04ea35d6-cd7d-d6de-75ae-59b1e0c77f04@marcan.st> From: Hector Martin Message-ID: <7c56c08f-9382-5db4-647a-1afae79c84de@marcan.st> Date: Sat, 6 Mar 2021 02:19:23 +0900 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:78.0) Gecko/20100101 Thunderbird/78.6.0 MIME-Version: 1.0 In-Reply-To: Content-Language: es-ES X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20210305_171933_793774_2BE14090 X-CRM114-Status: GOOD ( 12.22 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Transfer-Encoding: 7bit Content-Type: text/plain; charset="us-ascii"; Format="flowed" Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org On 06/03/2021 01.43, Arnd Bergmann wrote: > - setting ioremap() on PCI buses non-posted only makes them > only slower but not more reliable, because the non-posted flag > on the bus is discarded by the PCI host bridge. Note that this doesn't work here *anyway*. The fabric is picky in both directions: thou shalt use nGnRnE for on-SoC MMIO and nGnRE for PCIe windows, or else, SError. Since these devices can support *any* PCI device via Thunderbolt, making PCI drivers be the oddball ones needing special APIs would mean hundreds of changes needed - the vast majority of PCI drivers in the kernel use plain ioremap variants that don't have any flags to look at. -- Hector Martin (marcan@marcan.st) Public Key: https://mrcn.st/pub _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel