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=-9.8 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT autolearn=ham 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 B0E77C2D0DB for ; Fri, 24 Jan 2020 11:21:39 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 827A82075D for ; Fri, 24 Jan 2020 11:21:39 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1579864899; bh=3Ex/mXexqXxXMMGo1YyKzygo6nVNMvVs8fQmSKw30Sw=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=o2H2e8DqndmCUQHlaJUxlWnnE7nm9QFBg+P7oLl82JWIrXNsUhTuIRKbcnCPRRWEl DGm0VrNEulQTb+lEHhYvsxWENMlJzZHvBgA2WAZncKxqBd97WuYGK3kuleD+XlzjIw lTOt2XE2Izv3aXrcpbc7ndEyoFVeR2zWHMOukztc= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2391096AbgAXLVj (ORCPT ); Fri, 24 Jan 2020 06:21:39 -0500 Received: from mail.kernel.org ([198.145.29.99]:60034 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2390482AbgAXLVg (ORCPT ); Fri, 24 Jan 2020 06:21:36 -0500 Received: from localhost (ip-213-127-102-57.ip.prioritytelecom.net [213.127.102.57]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 22EC7206D4; Fri, 24 Jan 2020 11:21:34 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1579864895; bh=3Ex/mXexqXxXMMGo1YyKzygo6nVNMvVs8fQmSKw30Sw=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=GHW3U4K1LFpIWsNDUFrckIom88W8l9FWdYvu8wYXCuhGInVO/sTJJ+TitpEYQuERF 4Xl3tDdeNTbCRLEvt3WDBVVbEkKZseKoqXN403cQ173oUsIPRube/UBbF6D3C1aqlz y41L4E56RVyFxlAge2YKxkzOZzECid/v0c8xwBTs= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, "Rafael J. Wysocki" , Keith Busch , Mika Westerberg , Sasha Levin Subject: [PATCH 4.19 395/639] PCI: PM: Avoid possible suspend-to-idle issue Date: Fri, 24 Jan 2020 10:29:25 +0100 Message-Id: <20200124093136.400482106@linuxfoundation.org> X-Mailer: git-send-email 2.25.0 In-Reply-To: <20200124093047.008739095@linuxfoundation.org> References: <20200124093047.008739095@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Rafael J. Wysocki [ Upstream commit d491f2b75237ef37d8867830ab7fad8d9659e853 ] If a PCI driver leaves the device handled by it in D0 and calls pci_save_state() on the device in its ->suspend() or ->suspend_late() callback, it can expect the device to stay in D0 over the whole s2idle cycle. However, that may not be the case if there is a spurious wakeup while the system is suspended, because in that case pci_pm_suspend_noirq() will run again after pci_pm_resume_noirq() which calls pci_restore_state(), via pci_pm_default_resume_early(), so state_saved is cleared and the second iteration of pci_pm_suspend_noirq() will invoke pci_prepare_to_sleep() which may change the power state of the device. To avoid that, add a new internal flag, skip_bus_pm, that will be set by pci_pm_suspend_noirq() when it runs for the first time during the given system suspend-resume cycle if the state of the device has been saved already and the device is still in D0. Setting that flag will cause the next iterations of pci_pm_suspend_noirq() to set state_saved for pci_pm_resume_noirq(), so that it always restores the device state from the originally saved data, and avoid calling pci_prepare_to_sleep() for the device. Fixes: 33e4f80ee69b ("ACPI / PM: Ignore spurious SCI wakeups from suspend-to-idle") Signed-off-by: Rafael J. Wysocki Reviewed-by: Keith Busch Reviewed-by: Mika Westerberg Signed-off-by: Sasha Levin --- drivers/pci/pci-driver.c | 17 ++++++++++++++++- include/linux/pci.h | 1 + 2 files changed, 17 insertions(+), 1 deletion(-) diff --git a/drivers/pci/pci-driver.c b/drivers/pci/pci-driver.c index bc1ff41ce3d35..5c9873fcbd08b 100644 --- a/drivers/pci/pci-driver.c +++ b/drivers/pci/pci-driver.c @@ -736,6 +736,8 @@ static int pci_pm_suspend(struct device *dev) struct pci_dev *pci_dev = to_pci_dev(dev); const struct dev_pm_ops *pm = dev->driver ? dev->driver->pm : NULL; + pci_dev->skip_bus_pm = false; + if (pci_has_legacy_pm_support(pci_dev)) return pci_legacy_suspend(dev, PMSG_SUSPEND); @@ -829,7 +831,20 @@ static int pci_pm_suspend_noirq(struct device *dev) } } - if (!pci_dev->state_saved) { + if (pci_dev->skip_bus_pm) { + /* + * The function is running for the second time in a row without + * going through full resume, which is possible only during + * suspend-to-idle in a spurious wakeup case. Moreover, the + * device was originally left in D0, so its power state should + * not be changed here and the device register values saved + * originally should be restored on resume again. + */ + pci_dev->state_saved = true; + } else if (pci_dev->state_saved) { + if (pci_dev->current_state == PCI_D0) + pci_dev->skip_bus_pm = true; + } else { pci_save_state(pci_dev); if (pci_power_manageable(pci_dev)) pci_prepare_to_sleep(pci_dev); diff --git a/include/linux/pci.h b/include/linux/pci.h index b1f297f4b7b0b..94853094b6ef4 100644 --- a/include/linux/pci.h +++ b/include/linux/pci.h @@ -342,6 +342,7 @@ struct pci_dev { D3cold, not set for devices powered on/off by the corresponding bridge */ + unsigned int skip_bus_pm:1; /* Internal: Skip bus-level PM */ unsigned int ignore_hotplug:1; /* Ignore hotplug events */ unsigned int hotplug_user_indicators:1; /* SlotCtl indicators controlled exclusively by -- 2.20.1