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,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 0FB71C4167B for ; Fri, 4 Dec 2020 07:36:53 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id A902522571 for ; Fri, 4 Dec 2020 07:36:52 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727984AbgLDHgg (ORCPT ); Fri, 4 Dec 2020 02:36:36 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:58270 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727831AbgLDHgg (ORCPT ); Fri, 4 Dec 2020 02:36:36 -0500 Received: from mail-ed1-x543.google.com (mail-ed1-x543.google.com [IPv6:2a00:1450:4864:20::543]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id F03B3C061A53 for ; Thu, 3 Dec 2020 23:35:55 -0800 (PST) Received: by mail-ed1-x543.google.com with SMTP id cw27so4821646edb.5 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=R9xeLrMy2xtL6BudutDxYd2/Nb4Dry6nqysMaxXjDHLxAS+W7bgvED1ESLoYDz8N+b xtXbvvDKfJ4JSBfrYKSpOHf9JkHcnQObxT/B0mvrn60bu/t6MYVanw4f5uAI8w4e0Gxe 4CXTco6PJ5o0UcW8h2V43UqqHj6ET8AC5+zm3k7oKdMfWzjrpq/exWq85bb47pfie7mV y9ZhZcJz9SRTYL5PBnQ5fCPoS1ELX2y2FM3i+KALs6wthJHw4rt8o8COU4vkax9OVY9P vHHQi2V3zaZGkkzgN/9klFaSSfyqZF3spkazH7WP0hUHXMXUNMzninZFBKfLvdNeKOKT lLgw== X-Gm-Message-State: AOAM531qtfo+Igt9OC1PzQN3MCixhY6OZHxYCMdDqWlzVtkKHt1F1iOf DXaAAkLot5lJTmHQYq914VASFvp4YRIYITsdei9o2Q== 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-pci@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/