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 7BB8BC433F5 for ; Thu, 9 Sep 2021 12:59:59 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 64D306115B for ; Thu, 9 Sep 2021 12:59:59 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1343682AbhIINBB (ORCPT ); Thu, 9 Sep 2021 09:01:01 -0400 Received: from mail.kernel.org ([198.145.29.99]:57772 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1355216AbhIIMxL (ORCPT ); Thu, 9 Sep 2021 08:53:11 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id 1B59F63229; Thu, 9 Sep 2021 11:57:30 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1631188650; bh=N6fSByMlmG9qV2AxfprHcTbNrvVZi8mJ76xTOXes9K8=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=Dlb3F3ALLqUBudEXnCgfZuYt3VoClsT0OF1HDCe8JOaDGC6vsMsoKcJFlY+jQ28nG yQxNvxnedYDgR1B0zVyaAvrihttOnfJkYcshm5rp0mOEDv+liMsRFPqMjISajR/K9Q n8IkafSsoLxEKMrvTd/oxkF1quNy33cnDwPVvUkcpdLP5HGArQOd91gIMOF/9t2u1c 4EgmvspBaqlAfDwCKWYaBzrcheQiSQky8JVKlpJAj1EG9ojgi10JlCmvawPU4yjOyp LyNEN6ogtdw8m8XxPxfM293YAsmvqcHAYndb92/v+3/JC6fXNVUl12E0VoQg92A4nh itsHSo/hLZLKQ== 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 4.19 03/74] PCI: Use pci_update_current_state() in pci_enable_device_flags() Date: Thu, 9 Sep 2021 07:56:15 -0400 Message-Id: <20210909115726.149004-3-sashal@kernel.org> X-Mailer: git-send-email 2.30.2 In-Reply-To: <20210909115726.149004-1-sashal@kernel.org> References: <20210909115726.149004-1-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-pci@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 9ebf32de8575..7228da4d5847 100644 --- a/drivers/pci/pci.c +++ b/drivers/pci/pci.c @@ -1591,11 +1591,7 @@ 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