From patchwork Sat Dec 17 14:39:39 2016 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Lukas Wunner X-Patchwork-Id: 9479035 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id B65446082E for ; Sat, 17 Dec 2016 14:40:49 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id A8F6B2848D for ; Sat, 17 Dec 2016 14:40:49 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 9DDB028449; Sat, 17 Dec 2016 14:40:49 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-6.9 required=2.0 tests=BAYES_00,RCVD_IN_DNSWL_HI autolearn=unavailable version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 50FCB2848D for ; Sat, 17 Dec 2016 14:40:49 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756977AbcLQOkb (ORCPT ); Sat, 17 Dec 2016 09:40:31 -0500 Received: from mailout2.hostsharing.net ([83.223.90.233]:60923 "EHLO mailout2.hostsharing.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756949AbcLQOkb (ORCPT ); Sat, 17 Dec 2016 09:40:31 -0500 Received: from h08.hostsharing.net (h08.hostsharing.net [83.223.95.28]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mailout2.hostsharing.net (Postfix) with ESMTPS id 3FCFD103CFCE8; Sat, 17 Dec 2016 15:40:28 +0100 (CET) Received: from localhost (3-38-90-81.adsl.cmo.de [81.90.38.3]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-SHA (128/128 bits)) (No client certificate requested) by h08.hostsharing.net (Postfix) with ESMTPSA id B0914608554F; Sat, 17 Dec 2016 15:40:26 +0100 (CET) X-Mailbox-Line: From d931ba2adbbdcda4c04b677fb8a196a8e35c025d Mon Sep 17 00:00:00 2001 Message-Id: In-Reply-To: References: From: Lukas Wunner Date: Sat, 17 Dec 2016 15:39:39 +0100 Subject: [PATCH v3 2/7] PCI: Allow runtime PM on Thunderbolt ports To: Greg Kroah-Hartman , linux-kernel@vger.kernel.org Cc: Andreas Noever , linux-pci@vger.kernel.org, linux-pm@vger.kernel.org, Tomas Winkler , Amir Levy , Bjorn Helgaas , Mika Westerberg , "Rafael J. Wysocki" Sender: linux-pm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-pm@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP Currently PCIe ports are only allowed to go to D3 if the BIOS is dated 2015 or newer to avoid potential issues with old chipsets. However for Thunderbolt we know that even the oldest controller, Light Ridge (2010), is able to suspend its ports to D3 just fine. We're about to add runtime PM for Thunderbolt on the Mac. Apple has released two EFI security updates in 2015 which encompass all machines with Thunderbolt, but the achieved power saving should be made available to users even if they haven't updated their BIOS. To this end, special-case Thunderbolt in pci_bridge_d3_possible(). This allows the Thunderbolt controller to power down but the root port to which the Thunderbolt controller is attached remains in D0 unless the EFI update is installed. Users can pass pcie_port_pm=force on the kernel command line if they cannot install the EFI update but still want to benefit from the additional power saving of putting the root port into D3. In practice, root ports can be suspended to D3 without issues at least on 2012 Ivy Bridge machines. If the BIOS cut-off date is ever lowered to 2010, the Thunderbolt special case can be removed. Cc: Mika Westerberg Cc: Rafael J. Wysocki Cc: Andreas Noever Cc: Tomas Winkler Cc: Amir Levy Signed-off-by: Lukas Wunner --- drivers/pci/pci.c | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-) diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c index a881c0d..8ed098d 100644 --- a/drivers/pci/pci.c +++ b/drivers/pci/pci.c @@ -2224,7 +2224,7 @@ void pci_config_pm_runtime_put(struct pci_dev *pdev) * @bridge: Bridge to check * * This function checks if it is possible to move the bridge to D3. - * Currently we only allow D3 for recent enough PCIe ports. + * Currently we only allow D3 for recent enough PCIe ports and Thunderbolt. */ bool pci_bridge_d3_possible(struct pci_dev *bridge) { @@ -2258,6 +2258,11 @@ bool pci_bridge_d3_possible(struct pci_dev *bridge) year >= 2015) { return true; } + + /* Even the oldest 2010 Thunderbolt controller supports D3. */ + if (bridge->is_thunderbolt) + return true; + break; }