From patchwork Sun Sep 18 03:39:20 2016 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Lukas Wunner X-Patchwork-Id: 9337531 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 833C06089F for ; Sun, 18 Sep 2016 03:40:05 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 77900292D1 for ; Sun, 18 Sep 2016 03:40:05 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 6B8402937E; Sun, 18 Sep 2016 03:40:05 +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 0C9ED2932B for ; Sun, 18 Sep 2016 03:39:52 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756092AbcIRDju (ORCPT ); Sat, 17 Sep 2016 23:39:50 -0400 Received: from mailout2.hostsharing.net ([83.223.90.233]:36377 "EHLO mailout2.hostsharing.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756077AbcIRDjt (ORCPT ); Sat, 17 Sep 2016 23:39:49 -0400 Received: from h08.hostsharing.net (h08.hostsharing.net [83.223.95.28]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mailout2.hostsharing.net (Postfix) with ESMTPS id 568321018C44C; Sun, 18 Sep 2016 05:39:46 +0200 (CEST) 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 D7C59603E217; Sun, 18 Sep 2016 05:39:44 +0200 (CEST) X-Mailbox-Line: From 8661098ee5e355f91e9d9c61248e3ac9980b16aa Mon Sep 17 00:00:00 2001 Message-Id: <8661098ee5e355f91e9d9c61248e3ac9980b16aa.1474130360.git.lukas@wunner.de> In-Reply-To: References: From: Lukas Wunner Date: Sun, 18 Sep 2016 05:39:20 +0200 Subject: [PATCH v2 1/5] PCI: Afford direct-complete to devices with nonstandard PM To: linux-pci@vger.kernel.org Cc: linux-pm@vger.kernel.org, linux-acpi@vger.kernel.org, "Rafael J. Wysocki" , Peter Wu , Andreas Noever 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 There are devices not power-manageable by the platform, but still able to runtime suspend to D3cold with a nonstandard mechanism. One example is laptop hybrid graphics where the discrete GPU and its built-in HDA controller are power-managed either with a _DSM (AMD PowerXpress, Nvidia Optimus) or a separate gmux controller (MacBook Pro). Another example is Thunderbolt on Macs which is power-managed with custom ACPI methods. When putting the system to sleep, we currently handle such devices improperly by transitioning them from D3cold to D3hot (the default power state defined at the top of pci_target_state()). This wastes energy and prolongs the suspend sequence (powering up the Thunderbolt controller takes 2 seconds). Avoid that by assuming that a nonstandard PM mechanism is at work if the device is not platform-power-manageable but currently in D3cold. If the device is wakeup enabled, we might still have to wake it up from D3cold if PME cannot be signaled from that power state. The check for devices without PM capability comes before the check for D3cold since such devices could in theory also be powered down by nonstandard means and should then be afforded direct-complete as well. Signed-off-by: Lukas Wunner Acked-by: Rafael J. Wysocki --- drivers/pci/pci.c | 17 +++++++++++++++-- 1 file changed, 15 insertions(+), 2 deletions(-) diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c index aab9d51..72a9d3a 100644 --- a/drivers/pci/pci.c +++ b/drivers/pci/pci.c @@ -1959,9 +1959,22 @@ static pci_power_t pci_target_state(struct pci_dev *dev) default: target_state = state; } - } else if (!dev->pm_cap) { + + return target_state; + } + + if (!dev->pm_cap) target_state = PCI_D0; - } else if (device_may_wakeup(&dev->dev)) { + + /* + * If the device is in D3cold even though it's not power-manageable by + * the platform, it may have been powered down by nonstandard means. + * Best to let it slumber. + */ + if (dev->current_state == PCI_D3cold) + target_state = PCI_D3cold; + + if (device_may_wakeup(&dev->dev)) { /* * Find the deepest state from which the device can generate * wake-up events, make it the target state and enable device