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=-3.5 required=3.0 tests=BAYES_00,DKIM_INVALID, DKIM_SIGNED,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 58243C433E6 for ; Sat, 29 Aug 2020 07:24:16 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 36C0A207BB for ; Sat, 29 Aug 2020 07:24:16 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b="pLldZGWX" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727046AbgH2HYP (ORCPT ); Sat, 29 Aug 2020 03:24:15 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:43604 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726083AbgH2HYM (ORCPT ); Sat, 29 Aug 2020 03:24:12 -0400 Received: from casper.infradead.org (casper.infradead.org [IPv6:2001:8b0:10b:1236::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id ECAEEC061236; Sat, 29 Aug 2020 00:24:11 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=casper.20170209; h=In-Reply-To:Content-Type:MIME-Version: References:Message-ID:Subject:Cc:To:From:Date:Sender:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description; bh=b660aar3g6/JJYoLm+eUfNa34ts9ix4M3QDleqnb3gw=; b=pLldZGWXJimg9P6mCsRrKFdTvx +tWqoU3zirJpqHj3nuY9IUdwAoEZ8YOdTXpXJWJtn9vvTq/wqjz41X/A/k2SYiOsqE4IUDymkW8DO xUYByzEanMFhZnR3d7nZvrz5zl05p9eCYDHPcCf1L86lgms0eK3T6ypnKnZJWC2AThGDDT3jAp5+8 XXQRTrWOljEIBxOAq7tKEILzHXZ/qONGxGMGuBT8j4ke8Ag3Mgm4yFf3hhbW+xDNnLKBNlkB0yEU/ MJQaMlooU3V6aQYg3TP7bin0Ow487p2hXtDdW57xRAhHa+rddzTvDyu3OP1lt+6kQejtHiLIUxjtk q2cL9stg==; Received: from hch by casper.infradead.org with local (Exim 4.92.3 #3 (Red Hat Linux)) id 1kBvDZ-0001qk-Bp; Sat, 29 Aug 2020 07:24:05 +0000 Date: Sat, 29 Aug 2020 08:24:05 +0100 From: "hch@infradead.org" To: "Limonciello, Mario" Cc: "hch@infradead.org" , "Derrick, Jonathan" , "wangxiongfeng2@huawei.com" , "kw@linux.com" , "hkallweit1@gmail.com" , "kai.heng.feng@canonical.com" , "linux-kernel@vger.kernel.org" , "mika.westerberg@linux.intel.com" , "linux-pci@vger.kernel.org" , "Williams, Dan J" , "bhelgaas@google.com" , "Huffman, Amber" , "Wysocki, Rafael J" Subject: Re: [PATCH] PCI/ASPM: Enable ASPM for links under VMD domain Message-ID: <20200829072405.GB6704@infradead.org> References: <20200821123222.32093-1-kai.heng.feng@canonical.com> <20200825062320.GA27116@infradead.org> <20200827063406.GA13738@infradead.org> <660c8671a51eec447dc7fab22bacbc9c600508d9.camel@intel.com> <20200827162333.GA6822@infradead.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: X-SRS-Rewrite: SMTP reverse-path rewritten from by casper.infradead.org. See http://www.infradead.org/rpr.html Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Aug 27, 2020 at 05:49:40PM +0000, Limonciello, Mario wrote: > Can you further elaborate what exactly you're wanting here? VMD enable/disable > is something that is configured in firmware setup as the firmware does the early > configuration for the silicon related to it. So it's up to the OEM whether to > offer the knob to an end user. > > At least for Dell this setting also does export to sysfs and can be turned on/off > around a reboot cycle via this: https://patchwork.kernel.org/patch/11693231/. > > As was mentioned earlier in this thread VMD is likely to be defaulting to "on" > for many machines with the upcoming silicon. Making it work well on Linux is > preferable to again having to change firmware settings between operating systems > like the NVME remapping thing from earlier silicon required. And the right answer is to turn it off, but we really need to do that at runtime, and not over a reboot cycle..