From mboxrd@z Thu Jan 1 00:00:00 1970 From: Bartlomiej Zolnierkiewicz Subject: Re: [PATCH 2/4] PM / Domains: Enable users of genpd to specify always on PM domains Date: Mon, 20 Mar 2017 18:10:55 +0100 Message-ID: <106439272.Agr7nxKMxr@amdc3058> References: <1490005163-28633-1-git-send-email-ulf.hansson@linaro.org> <1490005163-28633-3-git-send-email-ulf.hansson@linaro.org> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7Bit Return-path: Received: from mailout2.samsung.com ([203.254.224.25]:38318 "EHLO mailout2.samsung.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753217AbdCTRnB (ORCPT ); Mon, 20 Mar 2017 13:43:01 -0400 Received: from epcas1p3.samsung.com (unknown [182.195.41.47]) by mailout2.samsung.com (Oracle Communications Messaging Server 7.0.5.31.0 64bit (built May 5 2014)) with ESMTP id <0ON402LE6IE9VM50@mailout2.samsung.com> for linux-pm@vger.kernel.org; Tue, 21 Mar 2017 02:10:57 +0900 (KST) In-reply-to: <1490005163-28633-3-git-send-email-ulf.hansson@linaro.org> Sender: linux-pm-owner@vger.kernel.org List-Id: linux-pm@vger.kernel.org To: Ulf Hansson Cc: "Rafael J . Wysocki" , linux-pm@vger.kernel.org, Len Brown , Pavel Machek , Kevin Hilman , Geert Uytterhoeven , Lina Iyer , Jon Hunter , Marek Szyprowski , Viresh Kumar On Monday, March 20, 2017 11:19:21 AM Ulf Hansson wrote: > The current way to implement an always on PM domain consists of returning > -EBUSY from the ->power_off() callback. This is a bit different compared to > using the always on genpd governor, which prevents the PM domain from being > powered off via runtime suspend, but not via system suspend. > > The approach to return -EBUSY from the ->power_off() callback to support > always on PM domains in genpd is suboptimal. That is because it requires > genpd to follow the regular execution path of the power off sequence, which > ends by invoking the ->power_off() callback. > > To enable genpd to early abort the power off sequence for always on PM > domains, it needs static information about these configurations. Therefore > let's add a new genpd configuration flag, GENPD_FLAG_ALWAYS_ON. > > Users of the new GENPD_FLAG_ALWAYS_ON flag, are by genpd required to make > sure the PM domain is powered on before calling pm_genpd_init(). Moreover, > users don't need to implement the ->power_off() callback, as genpd doesn't > ever invoke it. > > Signed-off-by: Ulf Hansson Reviewed-by: Bartlomiej Zolnierkiewicz Best regards, -- Bartlomiej Zolnierkiewicz Samsung R&D Institute Poland Samsung Electronics