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 85EF3C4361A 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 237EC22571 for ; Fri, 4 Dec 2020 07:36:51 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727957AbgLDHgg (ORCPT ); Fri, 4 Dec 2020 02:36:36 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:58266 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726669AbgLDHgg (ORCPT ); Fri, 4 Dec 2020 02:36:36 -0500 Received: from mail-ed1-x541.google.com (mail-ed1-x541.google.com [IPv6:2a00:1450:4864:20::541]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id DDEC8C061A51 for ; Thu, 3 Dec 2020 23:35:55 -0800 (PST) Received: by mail-ed1-x541.google.com with SMTP id cm17so4836044edb.4 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=XHR0OXbhkd64Tl3nQrpRg2DiEAkl8C9FSgceUZK1EBYEeumxANxvL9HwK54h7JJIdc vYV/C23XTPQgU8KxMv88CZnPeVjaqXhOStM6R9cG8TzzsmYg25Ryu8ghRKT8HXPDZt3W BvCi0Ea0HVE07Xfv+c3H6xjKNYI56ipagtTIMnCqZTGvR/7P0nBuR8HczH1K3+Bilx4o AvvopImSNoohqhGeWWPlcX7KH0UTt19xMN44d8KtQVKO7v0c+HVfrHouS2OywRMLdlUa hed6NXPU2bPV0SxDvXMfG4dg18KDkgbcsSnrD7ijUwfOHbz95kKlJXED47TpZ3y9c67L zlQg== X-Gm-Message-State: AOAM532Ce21vFzvs2Gmv+mDcrxtJb73v3Q8lT9Ruy7lWqaDfPT7EfZUt Bs0QhhrEruLLD6nXjjEsIE5ZoynI3YHhgV++r1UlSA== 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-cxl@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/