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=-10.1 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,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 23500C433FF for ; Mon, 5 Aug 2019 20:52:36 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id DDDED216B7 for ; Mon, 5 Aug 2019 20:52:35 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1565038356; bh=IOBQeBrjuJWC+xvDlUUCjyNQJ22b8xmF5sL15aFS4Wk=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=d3AFAe6Fr/ZOZekjIxTL1jYMe52CFb4MluEBZK7jQ4gAuH+90GZFxmH/lsg3P240p 3yXU3hu021hcqg8PDWK0q9556qtnlb1PBTD2wZgf7Xgk5bHMQXreRA6Sl31JesuQPN 2dvJ7wCcDERHfCAFrL/30+xbptBFK1zIBijDUo54= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730665AbfHEUwf (ORCPT ); Mon, 5 Aug 2019 16:52:35 -0400 Received: from mail.kernel.org ([198.145.29.99]:38928 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1730572AbfHEUwc (ORCPT ); Mon, 5 Aug 2019 16:52:32 -0400 Received: from localhost (unknown [64.22.228.164]) (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 D8779216B7; Mon, 5 Aug 2019 20:52:31 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1565038352; bh=IOBQeBrjuJWC+xvDlUUCjyNQJ22b8xmF5sL15aFS4Wk=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=RiHVRhFYnLOi2Bk2+3BKrMmmToRYVL6mc9VkXKFU7+DA8ZZ+o2GEuNoGUO+tK7dG9 NUnkGH14ev6E2SzPDu/cEZmpLoDBiDyfGMVSkT8eoRpDoYiLHrGG75vp5qUYjsG8nV 6+zSbxGYDMGhsprHTGCLXk1zq1FU4nihhIho42XQ= From: Bjorn Helgaas To: linux-pci@vger.kernel.org Cc: Lorenzo Pieralisi , Keith Busch , Greg Kroah-Hartman , "Rafael J . Wysocki" , Mika Westerberg , linux-pm@vger.kernel.org, linux-kernel@vger.kernel.org, Bjorn Helgaas Subject: [PATCH 2/5] PCI / PM: Return error when changing power state from D3cold Date: Mon, 5 Aug 2019 15:52:11 -0500 Message-Id: <20190805205214.194981-3-helgaas@kernel.org> X-Mailer: git-send-email 2.22.0.770.g0f2c4a37fd-goog In-Reply-To: <20190805205214.194981-1-helgaas@kernel.org> References: <20190805205214.194981-1-helgaas@kernel.org> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Bjorn Helgaas pci_raw_set_power_state() uses the Power Management capability to change a device's power state. The capability is in config space, which is accessible in D0, D1, D2, and D3hot, but not in D3cold. If we call pci_raw_set_power_state() on a device that's in D3cold, config reads fail and return ~0 data, which we erroneously interpreted as "the device is in D3hot", leading to messages like this: pcieport 0000:03:00.0: Refused to change power state, currently in D3 The PCI_PM_CTRL has several RsvdP fields, so ~0 is never a valid register value. Notice if we get that data, print a more informative message, and return an error. Changing the power state of a device from D3cold must be done by a platform power management method or some other non-config space mechanism. Signed-off-by: Bjorn Helgaas --- drivers/pci/pci.c | 5 +++++ 1 file changed, 5 insertions(+) diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c index bfc739dc6ada..984171d40858 100644 --- a/drivers/pci/pci.c +++ b/drivers/pci/pci.c @@ -851,6 +851,11 @@ static int pci_raw_set_power_state(struct pci_dev *dev, pci_power_t state) return -EIO; pci_read_config_word(dev, dev->pm_cap + PCI_PM_CTRL, &pmcsr); + if (pmcsr == (u16) PCI_ERROR_RESPONSE) { + pci_err(dev, "device not responding; can't change to power state D%d\n", + state); + return -EIO; + } /* * If we're (effectively) in D3, force entire word to 0. -- 2.22.0.770.g0f2c4a37fd-goog