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=-19.4 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,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 DB835C433EF for ; Thu, 9 Sep 2021 13:21:22 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id B6E7861051 for ; Thu, 9 Sep 2021 13:21:22 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1355912AbhIINWW (ORCPT ); Thu, 9 Sep 2021 09:22:22 -0400 Received: from mail.kernel.org ([198.145.29.99]:54052 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1357960AbhIINFn (ORCPT ); Thu, 9 Sep 2021 09:05:43 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id 3289B632A3; Thu, 9 Sep 2021 12:00:18 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1631188818; bh=uPU/8guFO9EvAbD4ZTmHSHBGGmF/WTSfkiHh+XU5aL4=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=PpjgYT7iLsmKFGlXABAl31UTQSuQASmnTFC4sXGOWlm0i3+n75SnbM9FveYP7iOwm o5YYuln8eEf1WL/vmZ1hqBkxsA+9UhkijXgns/t1vD3wdzyxo1zIo+0KUrVnC7QI5N qzAm7WUXDT9C1jsI6tIOwm2hrm/qng+XdJVla+52r9gu1rMFvGYW+U7JQMhsTu9vi0 JYPOiM9OQN19lsL7YMsjKxvVBmKw4fm6ZGY1RHiZH5cJsmh3epYMCER/+TIYCA2lHc GvleTfqhp7gI+mP+mZtJTB9aHXHQmF4c/N30B/RVB2WUuIkusfjlGNMPye8Sx0uHKK lVMIm3jHmQPUQ== From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: "Rafael J. Wysocki" , Maximilian Luz , Sasha Levin , linux-pci@vger.kernel.org Subject: [PATCH AUTOSEL 4.9 02/48] PCI: Use pci_update_current_state() in pci_enable_device_flags() Date: Thu, 9 Sep 2021 07:59:29 -0400 Message-Id: <20210909120015.150411-2-sashal@kernel.org> X-Mailer: git-send-email 2.30.2 In-Reply-To: <20210909120015.150411-1-sashal@kernel.org> References: <20210909120015.150411-1-sashal@kernel.org> MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore 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 e09653c73ab4..7b0d048a5415 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