From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756497AbaBFNO1 (ORCPT ); Thu, 6 Feb 2014 08:14:27 -0500 Received: from v094114.home.net.pl ([79.96.170.134]:53384 "HELO v094114.home.net.pl" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with SMTP id S1756397AbaBFNOE (ORCPT ); Thu, 6 Feb 2014 08:14:04 -0500 From: "Rafael J. Wysocki" To: Linux PM list Cc: ACPI Devel Maling List , LKML , Mika Westerberg Subject: [PATCH v3 0/6] PM / QoS: Introduce latency tolerance device PM QoS type Date: Thu, 06 Feb 2014 14:22:10 +0100 Message-ID: <1550670.IB7tE3uSq4@vostro.rjw.lan> User-Agent: KMail/4.11.4 (Linux/3.13.0+; KDE/4.11.4; x86_64; ; ) In-Reply-To: <1447517.8AFrWcAgld@vostro.rjw.lan> References: <5434847.aCyiWHNRe7@vostro.rjw.lan> <1447517.8AFrWcAgld@vostro.rjw.lan> MIME-Version: 1.0 Content-Transfer-Encoding: 7Bit Content-Type: text/plain; charset="utf-8" Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thursday, January 23, 2014 02:34:59 PM Rafael J. Wysocki wrote: > On Friday, January 17, 2014 03:42:13 PM Rafael J. Wysocki wrote: > > Hi All, > > > > On some platforms hardware may switch to an energy-saving mode on the fly > > on the basis of certain utilization metrics used by it. That usually is > > desirable from the energy conservation standpoint, but it generally causes > > latencies to increase which may adversely affect some operations. For this > > reason, the platforms in question usually provide some interfaces for software > > to indicate its latency tolerance and possibly to prevent the energy-saving > > modes from being selected too aggressively. > > > > The following series of patches introduces a device PM QoS type allowing > > those interfaces to be used by kernel code and user space. It is designed > > in analogy with the existing resume latency device PM QoS type, which allows > > some pieces of the existing device PM QoS code to be re-used and makes the > > new user space interface fit into the existing framework. > > > > Patch [1/5] modifies the names of symbols, variables, functions and structure > > fields associated with the existing resume latency device PM QoS type to > > avoid any confusion with the new one introduced by the subsequent patches. > > > > Patch [2/5] introduces a new field in struct pm_qos_constraints for specifying > > a special value to be returned as the effective requirement when the given list > > of PM QoS requirements is empty. That field is necessary for the new latency > > tolerance device PM QoS type. > > > > Patch [3/5] introduces the latency tolerance device PM QoS type along with > > documentation. > > > > Patch [4/5] modifies the ACPI LPSS (Low-Power Subsystem) driver to hook up > > LPSS devices to the new latency tolerance device PM QoS interface. > > > > Patch [5/5] modifies the dev_pm_qos_add_ancestor_request() routine so that it > > can be used by drivers of devices without hardware latency tolerance support > > for specifying their requirements via the ancestors of those devies. > > As usual, testing uncovered some issues, so an updated series follows. OK, no comments - no objections. Cool! :-) Time for a non-RFC submission I guess. The following series is almost the same as the previous one except for patch [5/6] that fixes a bug (LPSS_LTR_SNOOP_REQ has to be set along with LPSS_LTR_SNOOP_LAT_1US) and introduces a cutoff value such that all above it will mean "no requirement". Thanks! -- I speak only for myself. Rafael J. Wysocki, Intel Open Source Technology Center.