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=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 60792C33CAF for ; Thu, 16 Jan 2020 18:22:13 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 3A6D5208C3 for ; Thu, 16 Jan 2020 18:22:13 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1579198933; bh=MVuQihC75yyeoF/lahCObJDjcs4ywXW3oeFo6Zh6GIE=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=k7kjFOICvI1i2MZhx4AVKpx2UW4wSN3Z9frF+/NAx6iMaW8NJGYoVncC8AmOjrQNU w/n+DPFxP55XbB/lr+h+2yeKlgXeg/eayQK02/um46YXEP/t/TgV7i2Z+QT20x26d4 hDotnPcjpSNJCbveSglZrW+mCmTRqjjbki76Eg4M= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2392478AbgAPR1i (ORCPT ); Thu, 16 Jan 2020 12:27:38 -0500 Received: from mail.kernel.org ([198.145.29.99]:37608 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2390821AbgAPR1h (ORCPT ); Thu, 16 Jan 2020 12:27:37 -0500 Received: from sasha-vm.mshome.net (c-73-47-72-35.hsd1.nh.comcast.net [73.47.72.35]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id B4AEC246DC; Thu, 16 Jan 2020 17:27:35 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1579195656; bh=MVuQihC75yyeoF/lahCObJDjcs4ywXW3oeFo6Zh6GIE=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=2reit09ulDujz+8GyMgmEtoVYMj1UmcJzVBX03UtFapvWVnR4sWzaHgDVmptG3w1R wJ06mD6ndxoswhRhctL108pJl8VN7XFWR0h+IMQWJ+YC3ioRW+Sr3BWJl8FGEjGxn+ yWqAkvNIR//7Govug0KXDod1lx2IlDo2sahsXvQY= From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: "Rafael J. Wysocki" , Keith Busch , Mika Westerberg , Sasha Levin , linux-pci@vger.kernel.org Subject: [PATCH AUTOSEL 4.14 217/371] PCI: PM: Avoid possible suspend-to-idle issue Date: Thu, 16 Jan 2020 12:21:29 -0500 Message-Id: <20200116172403.18149-160-sashal@kernel.org> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20200116172403.18149-1-sashal@kernel.org> References: <20200116172403.18149-1-sashal@kernel.org> MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore Content-Transfer-Encoding: 8bit Sender: linux-pci-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-pci@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 522e59274b5d..1589a147c536 100644 --- a/drivers/pci/pci-driver.c +++ b/drivers/pci/pci-driver.c @@ -728,6 +728,8 @@ 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); @@ -801,7 +803,20 @@ 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 59f4d10568c6..430f3c335446 100644 --- a/include/linux/pci.h +++ b/include/linux/pci.h @@ -346,6 +346,7 @@ 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