From mboxrd@z Thu Jan 1 00:00:00 1970 Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752234AbeACM0Y (ORCPT + 1 other); Wed, 3 Jan 2018 07:26:24 -0500 Received: from mga01.intel.com ([192.55.52.88]:21657 "EHLO mga01.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751205AbeACM0W (ORCPT ); Wed, 3 Jan 2018 07:26:22 -0500 X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.45,501,1508828400"; d="scan'208";a="7706036" Subject: Re: [char-misc-next] mei: me: allow runtime pm for platform with D0i3 To: Tomas Winkler Cc: Greg Kroah-Hartman , Alexander Usyskin , linux-kernel@vger.kernel.org, stable@vger.kernel.org References: <20180102100141.703-1-tomas.winkler@intel.com> From: "Rafael J. Wysocki" Organization: Intel Technology Poland Sp. z o. o., KRS 101882, ul. Slowackiego 173, 80-298 Gdansk Message-ID: Date: Wed, 3 Jan 2018 13:26:22 +0100 User-Agent: Mozilla/5.0 (Windows NT 10.0; WOW64; rv:52.0) Gecko/20100101 Thunderbird/52.5.0 MIME-Version: 1.0 In-Reply-To: <20180102100141.703-1-tomas.winkler@intel.com> Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 8bit Content-Language: en-US Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Return-Path: On 1/2/2018 11:01 AM, Tomas Winkler wrote: > From the pci power documentation: > "The driver itself should not call pm_runtime_allow(), though. Instead, > it should let user space or some platform-specific code do that (user space > can do it via sysfs as stated above)..." > > However, the S0ix residency cannot be reached without MEI device getting > into low power state. Hence, for mei devices that support D0i3, it's better > to make runtime power management mandatory and not rely on the system > integration such as udev rules. It still is not mandatory with this change.  The default changes from "on" to "auto", but still user space can change it back to "on". The change itself look OK, though. > This policy cannot be applied globally as some older platforms > were found to have broken power management. > > Cc: v4.13+ > Cc: Rafael J. Wysocki > Signed-off-by: Tomas Winkler > Reviewed-by: Alexander Usyskin > --- > drivers/misc/mei/pci-me.c | 5 ++++- > 1 file changed, 4 insertions(+), 1 deletion(-) > > diff --git a/drivers/misc/mei/pci-me.c b/drivers/misc/mei/pci-me.c > index f4f17552c9b8..4a0ccda4d04b 100644 > --- a/drivers/misc/mei/pci-me.c > +++ b/drivers/misc/mei/pci-me.c > @@ -238,8 +238,11 @@ static int mei_me_probe(struct pci_dev *pdev, const struct pci_device_id *ent) > */ > mei_me_set_pm_domain(dev); > > - if (mei_pg_is_enabled(dev)) > + if (mei_pg_is_enabled(dev)) { > pm_runtime_put_noidle(&pdev->dev); > + if (hw->d0i3_supported) > + pm_runtime_allow(&pdev->dev); > + } > > dev_dbg(&pdev->dev, "initialization successful.\n"); >