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=-20.2 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER,INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, USER_AGENT_GIT autolearn=unavailable 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 DD587C433EF for ; Mon, 20 Sep 2021 17:05:58 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id C582F61529 for ; Mon, 20 Sep 2021 17:05:58 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1346460AbhITRHV (ORCPT ); Mon, 20 Sep 2021 13:07:21 -0400 Received: from mail.kernel.org ([198.145.29.99]:52718 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1345791AbhITREW (ORCPT ); Mon, 20 Sep 2021 13:04:22 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id BF7A161505; Mon, 20 Sep 2021 16:54:29 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1632156870; bh=WDKpplw7XuyvWrq9X460oyqH121aiwgm3bZhOkZtcmw=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=CELdxk0h2/l3RpRpph42j1WRtn+SHUhWyIqY/pJSu/SATwjZJnjt2HmGelFqN1/iB DCTVlfjQJwg0Uaxtp6jCbWPV1EpmG/eIUExeFE6Xh5/uOtw7KbUrmNAu7WqRuUDbGC UxV6A1SreNgSfGp6R+C6WG+5TssGG4xlhvR4Nbj0= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Maximilian Luz , "Rafael J. Wysocki" , Sasha Levin Subject: [PATCH 4.9 106/175] PCI: Use pci_update_current_state() in pci_enable_device_flags() Date: Mon, 20 Sep 2021 18:42:35 +0200 Message-Id: <20210920163921.543059133@linuxfoundation.org> X-Mailer: git-send-email 2.33.0 In-Reply-To: <20210920163918.068823680@linuxfoundation.org> References: <20210920163918.068823680@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Rafael J. Wysocki [ Upstream commit 14858dcc3b3587f4bb5c48e130ee7d68fc2b0a29 ] Updating the current_state field of struct pci_dev the way it is done in pci_enable_device_flags() before calling do_pci_enable_device() may not work. For example, if the given PCI device depends on an ACPI power resource whose _STA method initially returns 0 ("off"), but the config space of the PCI device is accessible and the power state retrieved from the PCI_PM_CTRL register is D0, the current_state field in the struct pci_dev representing that device will get out of sync with the power.state of its ACPI companion object and that will lead to power management issues going forward. To avoid such issues, make pci_enable_device_flags() call pci_update_current_state() which takes ACPI device power management into account, if present, to retrieve the current power state of the device. Link: https://lore.kernel.org/lkml/20210314000439.3138941-1-luzmaximilian@gmail.com/ Reported-by: Maximilian Luz Signed-off-by: Rafael J. Wysocki Tested-by: Maximilian Luz Signed-off-by: Sasha Levin --- drivers/pci/pci.c | 6 +----- 1 file changed, 1 insertion(+), 5 deletions(-) diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c index 510933ff6a26..2cf13578fe75 100644 --- a/drivers/pci/pci.c +++ b/drivers/pci/pci.c @@ -1384,11 +1384,7 @@ static int pci_enable_device_flags(struct pci_dev *dev, unsigned long flags) * so that things like MSI message writing will behave as expected * (e.g. if the device really is in D0 at enable time). */ - if (dev->pm_cap) { - u16 pmcsr; - pci_read_config_word(dev, dev->pm_cap + PCI_PM_CTRL, &pmcsr); - dev->current_state = (pmcsr & PCI_PM_CTRL_STATE_MASK); - } + pci_update_current_state(dev, dev->current_state); if (atomic_inc_return(&dev->enable_cnt) > 1) return 0; /* already enabled */ -- 2.30.2