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_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 DEF81C4361B for ; Fri, 4 Dec 2020 07:36:52 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 802D12255F for ; Fri, 4 Dec 2020 07:36:52 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728172AbgLDHgg (ORCPT ); Fri, 4 Dec 2020 02:36:36 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:58268 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727518AbgLDHgg (ORCPT ); Fri, 4 Dec 2020 02:36:36 -0500 Received: from mail-ed1-x544.google.com (mail-ed1-x544.google.com [IPv6:2a00:1450:4864:20::544]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id E8177C061A52 for ; Thu, 3 Dec 2020 23:35:55 -0800 (PST) Received: by mail-ed1-x544.google.com with SMTP id r5so4779480eda.12 for ; Thu, 03 Dec 2020 23:35:55 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=intel-com.20150623.gappssmtp.com; s=20150623; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=Ib4z7ovnO/Is9x9bv4eZdlrrRMtAOfboZBD7JQtUG5M=; b=MlznnxVBeS9Jeb9K6pxCGMSisJ5di5vo8rnZgccJEokQkubT+b5ELOaP/qYZPZYens LTQTZ5qK5+rN7i7TrBiUt/aTlSX5Si22lwK89sloMRq0lkL5fRELUsL6cmnUB3ewrYzQ 1C9XmpiDtksVcCp4aPdPDUu7mqzrhfTMil4Ii3r3Z+W4Rch+qHSCIy5nHqdZZHzjfuFC CouE9HwiB531iUdh3GBA/XBU2A5lxBYq8LwhDwqMK/fdnMIEGn+ShaX5yrUWSLlOXrdb pcuY+emGUnm4SuFF1EGQYrkKyVUfjNb/nVosCF9na3545V2UELil7agJD0NNoLsVMpuy +qqg== 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=Ib4z7ovnO/Is9x9bv4eZdlrrRMtAOfboZBD7JQtUG5M=; b=JEDOEO2513h9+blYem+6ZEE9vMNR7LZ4GF036v6/7atzjmyUY6am++vrFGarVPVarN DarP0awopHGELzOBVd5Qk1XKUVkQOL8dzceh0ZmG2LaG5Q7DQmf16J6XzTK8uPGQTF6P Y3ZQoqb0J0zTB2ppqqSAjUnHHVHEZ1aD994Hk4xTXa4pVrTv6Q1ga2abewf/tCzC6lmi XsVmELy9zcbH/Y97XPxuaRAnqsJdVaBJPHCJhAQGBDobqT77iP7m2rv2kSrbUKkqTM/X lLXD9OAJXIb9OXhlth/QuqK1WKgzRaMqwwOb7xzgcCbXOeU8JCk8Q8MBz1T5Et5WWfB6 J9bg== X-Gm-Message-State: AOAM532iEQGsTNYBPH2iNiBZntt0JG5vCVd/flNDiRcErCvqf1ySwDEz 43y1D8VBsDMSUdNsmesWkZPudMHglSquSCJWjRO5nAfzjfM+lw== X-Google-Smtp-Source: ABdhPJxnSZOAJkjodNrzG83gLmg0TXLoPO+mgtRWWPBjvZDtvRpGbpYSdnh6boOt1ZZAav86Y2rNmJuHLlFwPeiDAfk= X-Received: by 2002:a50:e00f:: with SMTP id e15mr6641049edl.210.1607067354664; Thu, 03 Dec 2020 23:35:54 -0800 (PST) MIME-Version: 1.0 References: <20201111054356.793390-1-ben.widawsky@intel.com> <20201111054356.793390-6-ben.widawsky@intel.com> <8d332852-9c54-95e0-58c7-72939f347aa6@jonmasters.org> In-Reply-To: <8d332852-9c54-95e0-58c7-72939f347aa6@jonmasters.org> From: Dan Williams Date: Thu, 3 Dec 2020 23:35:51 -0800 Message-ID: Subject: Re: [RFC PATCH 5/9] cxl/mem: Find device capabilities To: Jon Masters Cc: Ben Widawsky , linux-cxl@vger.kernel.org, Linux Kernel Mailing List , Linux PCI , Linux ACPI , Ira Weiny , Vishal Verma , "Kelley, Sean V" , Bjorn Helgaas , "Rafael J . Wysocki" Content-Type: text/plain; charset="UTF-8" Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Nov 25, 2020 at 10:06 PM Jon Masters wrote: > > On 11/11/20 12:43 AM, Ben Widawsky wrote: > > > + case CXL_CAPABILITIES_CAP_ID_SECONDARY_MAILBOX: > > + dev_dbg(&cxlm->pdev->dev, > > + "found UNSUPPORTED Secondary Mailbox capability\n"); > > Per spec, the secondary mailbox is intended for use by platform > firmware, so Linux should never be using it anyway. Maybe that message > is slightly misleading? > > Jon. > > P.S. Related - I've severe doubts about the mailbox approach being > proposed by CXL and have begun to push back through the spec org. The more Linux software voices the better. At the same time the spec is released so we're into xkcd territory [1] of what the driver will be expected to support for any future improvements. [1]: https://xkcd.com/927/