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 A9A40C433FE 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 5135A22597 for ; Fri, 4 Dec 2020 07:36:52 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727911AbgLDHgg (ORCPT ); Fri, 4 Dec 2020 02:36:36 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:58264 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727452AbgLDHgg (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 D7F15C061A4F for ; Thu, 3 Dec 2020 23:35:55 -0800 (PST) Received: by mail-ed1-x544.google.com with SMTP id u19so4834380edx.2 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=VtBSe6cXTqlEim6KytjBnzNCf1CpO8P3HmXdFLej0lFsdjhBHvboLvNUyOVvecEuuw ruh1JbCgp1cvLoIpetIfWVz+iLvR5taNZwNb3pEzB9o8mCON1QTXKCm3vfIXcs5r2spz fEBUWL4TSofBber4qrYh57dWW7oOgWVitIpjRBWAJ30Xueve99D3wvicRxcmjZgi9zJR aoTiLNvALP6Pub+mA1W7oMo55ik6uhZmBoaVosPqvm/fZ62an0lzm8o531qi4sd9SaxP UHa9pO/ZdEsDe0xGAeiu4pfSJfCdw14ve7NTJJ0M9fwTXNqQkq09zsaxs2UshFObzBUI K+xw== X-Gm-Message-State: AOAM532MwWlIB1LrALy+1O3QfEbuZRUbctrFx1XB2CrI6NwSv1N8INNg NCSLiBKSkGFsQZZf6gaBY/BOGmkSVfNL3DFgCmNuDg== 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-acpi@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/