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=-2.2 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_PASS,URIBL_BLOCKED,USER_AGENT_MUTT 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 4E9BDC43144 for ; Tue, 26 Jun 2018 10:33:35 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 09C9226957 for ; Tue, 26 Jun 2018 10:33:35 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 09C9226957 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=linux.intel.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S964976AbeFZKdd (ORCPT ); Tue, 26 Jun 2018 06:33:33 -0400 Received: from mga02.intel.com ([134.134.136.20]:27980 "EHLO mga02.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S933784AbeFZKda (ORCPT ); Tue, 26 Jun 2018 06:33:30 -0400 X-Amp-Result: UNSCANNABLE X-Amp-File-Uploaded: False Received: from orsmga004.jf.intel.com ([10.7.209.38]) by orsmga101.jf.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 26 Jun 2018 03:33:30 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.51,274,1526367600"; d="scan'208";a="211233259" Received: from lahna.fi.intel.com (HELO lahna) ([10.237.72.157]) by orsmga004.jf.intel.com with SMTP; 26 Jun 2018 03:33:27 -0700 Received: by lahna (sSMTP sendmail emulation); Tue, 26 Jun 2018 13:33:26 +0300 Date: Tue, 26 Jun 2018 13:33:26 +0300 From: Mika Westerberg To: "Rafael J. Wysocki" Cc: Linux PCI , n0000b.n000b@gmail.com, Bjorn Helgaas , LKML , Linux ACPI , Linux PM , Lukas Wunner Subject: Re: [PATCH] PCI / ACPI / PM: Resume bridges w/o drivers on suspend-to-RAM Message-ID: <20180626103326.GY2558@lahna.fi.intel.com> References: <35587465.8Nave9aG7d@aspire.rjw.lan> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <35587465.8Nave9aG7d@aspire.rjw.lan> Organization: Intel Finland Oy - BIC 0357606-4 - Westendinkatu 7, 02160 Espoo User-Agent: Mutt/1.10.0 (2018-05-17) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Jun 26, 2018 at 12:06:01PM +0200, Rafael J. Wysocki wrote: > From: Rafael J. Wysocki > > It is reported that commit c62ec4610c40 (PM / core: Fix direct_complete > handling for devices with no callbacks) introduced a system suspend > regression on Samsung 305V4A by allowing a PCI bridge (not a PCIe > port) to stay in D3 over suspend-to-RAM, which is a side effect of > setting power.direct_complete for the children of that bridge that > have no PM callbacks. > > On the majority of systems PCI bridges are not allowed to be > runtime-suspended (the power/control sysfs attribute is set to "on" > for them by default), but user space can change that setting and if > it does so and a given bridge has no children with PM callbacks, the > direct_complete optimization will be applied to it and it will stay > in suspend over system suspend. Apparently, that confuses the > platform firmware on the affected machine and that may very well > happen elsewhere, so avoid the direct_complete optimization for > PCI bridges with no drivers (if there is a driver, it should take > care of the PM handling) on suspend-to-RAM altogether (that should > not matter for suspend-to-idle as platform firmware is not involved > in it). > > Fixes: c62ec4610c40 (PM / core: Fix direct_complete handling for devices with no callbacks) > Link: https://bugzilla.kernel.org/show_bug.cgi?id=199941 > Reported-by: n0000b.n000b@gmail.com > Tested-by: n0000b.n000b@gmail.com > Signed-off-by: Rafael J. Wysocki Reviewed-by: Mika Westerberg