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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id E1C7ECDB465 for ; Sat, 14 Oct 2023 10:53:44 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232977AbjJNKxo (ORCPT ); Sat, 14 Oct 2023 06:53:44 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:57354 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232957AbjJNKxn (ORCPT ); Sat, 14 Oct 2023 06:53:43 -0400 Received: from bmailout3.hostsharing.net (bmailout3.hostsharing.net [176.9.242.62]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 524ACAD for ; Sat, 14 Oct 2023 03:53:41 -0700 (PDT) Received: from h08.hostsharing.net (h08.hostsharing.net [83.223.95.28]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256 client-signature RSA-PSS (4096 bits) client-digest SHA256) (Client CN "*.hostsharing.net", Issuer "RapidSSL Global TLS RSA4096 SHA256 2022 CA1" (verified OK)) by bmailout3.hostsharing.net (Postfix) with ESMTPS id B8F9E101956D2; Sat, 14 Oct 2023 12:53:38 +0200 (CEST) Received: by h08.hostsharing.net (Postfix, from userid 100393) id 861B42D957; Sat, 14 Oct 2023 12:53:38 +0200 (CEST) Date: Sat, 14 Oct 2023 12:53:38 +0200 From: Lukas Wunner To: Mario Limonciello Cc: Bjorn Helgaas , Hans de Goede , Ilpo =?iso-8859-1?Q?J=E4rvinen?= , "Rafael J . Wysocki" , Shyam Sundar S K , "open list:PCI SUBSYSTEM" , Kai-Heng Feng Subject: Re: [RFC v1 2/4] PCI: Add support for drivers to decide bridge D3 policy Message-ID: <20231014105338.GA3223@wunner.de> References: <20231009225653.36030-1-mario.limonciello@amd.com> <20231009225653.36030-3-mario.limonciello@amd.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20231009225653.36030-3-mario.limonciello@amd.com> User-Agent: Mutt/1.10.1 (2018-07-13) Precedence: bulk List-ID: X-Mailing-List: linux-pci@vger.kernel.org On Mon, Oct 09, 2023 at 05:56:51PM -0500, Mario Limonciello wrote: > commit 9d26d3a8f1b0 ("PCI: Put PCIe ports into D3 during suspend") > changed pci_bridge_d3_possible() so that any vendor's PCIe ports > from modern machines (>=2015) are allowed to be put into D3. > > This policy change has worked for most machines, but the behavior > is improved with `pcie_port_pm=off` on some others. > > Add support for drivers to register a callback that they can optionally > use to decide the policy on supported machines. I would assume that drivers can decide the policy already today through pci_d3cold_enable() / pci_d3cold_disable(). Why is this not sufficient and what's the benefit of the more complex approach proposed here? Thanks, Lukas