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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 2DBC8C3DA7A for ; Wed, 28 Dec 2022 18:43:12 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232989AbiL1SnK (ORCPT ); Wed, 28 Dec 2022 13:43:10 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:34730 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229964AbiL1SnJ (ORCPT ); Wed, 28 Dec 2022 13:43:09 -0500 Received: from dfw.source.kernel.org (dfw.source.kernel.org [139.178.84.217]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 78BA11277B; Wed, 28 Dec 2022 10:43:08 -0800 (PST) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id 14F2561562; Wed, 28 Dec 2022 18:43:08 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 68ED9C433F0; Wed, 28 Dec 2022 18:43:06 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1672252987; bh=FMJ5UprBCwio09MGzEBkUZaQkPXuO1St7XOYtOcq3Dc=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=d6FBiBiHDhwAsFIJNB1hrFP7NA11M+ifgxvfPjZe8sppWBJesiG+sQKAG3vwPUsWS nuDCIzxJZLuygfp1EfMEcl+7QMxwXFjf4C00CE0VPzs8TWnP/WLl+G4cS7JbZm9nzl 5qleLgrKBaoDOksDzEgE+p+1H9UoHntcA26Je/9XFinRdAjU4R+2PjeXllRqEbz0zo kuTC9AqebM5bpHz6NPsp7U1IRH2K4I8bSiFpjwrMXpy94YQZ0Oe8+W8A2MuyZNZuPf 8P8oPw0b6Ds3FcUVxYo8b9bDbsNDE7/5V47PiYD+TSA6qnRXjhc6tCDswU49mMr+QF fpazVm/rSojjA== Date: Wed, 28 Dec 2022 12:43:04 -0600 From: Bjorn Andersson To: Akhil P Oommen , "Rafael J. Wysocki" Cc: freedreno , dri-devel@lists.freedesktop.org, linux-arm-msm@vger.kernel.org, Rob Clark , Ulf Hansson , Stephen Boyd , Philipp Zabel , Greg Kroah-Hartman , Kevin Hilman , Len Brown , Pavel Machek , linux-kernel@vger.kernel.org, linux-pm@vger.kernel.org Subject: Re: [PATCH v4 1/5] PM: domains: Allow a genpd consumer to require a synced power off Message-ID: <20221228184304.4lldh7dxp2pnplzc@builder.lan> References: <1671642843-5244-1-git-send-email-quic_akhilpo@quicinc.com> <20221221224338.v4.1.I3e6b1f078ad0f1ca9358c573daa7b70ec132cdbe@changeid> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20221221224338.v4.1.I3e6b1f078ad0f1ca9358c573daa7b70ec132cdbe@changeid> Precedence: bulk List-ID: X-Mailing-List: linux-arm-msm@vger.kernel.org On Wed, Dec 21, 2022 at 10:43:59PM +0530, Akhil P Oommen wrote: > From: Ulf Hansson > > Some genpd providers doesn't ensure that it has turned off at hardware. > This is fine until the consumer really requires during some special > scenarios that the power domain collapse at hardware before it is > turned ON again. > > An example is the reset sequence of Adreno GPU which requires that the > 'gpucc cx gdsc' power domain should move to OFF state in hardware at > least once before turning in ON again to clear the internal state. > > Signed-off-by: Ulf Hansson > Signed-off-by: Akhil P Oommen Reviewed-by: Bjorn Andersson @Rafael, would you be willing to share an immutable branch with this change? Or would you be okay with me doing so from the qcom clock tree? Regards, Bjorn > --- > > Changes in v4: > - Update genpd function documentation (Ulf) > > Changes in v2: > - Minor formatting fix > > drivers/base/power/domain.c | 26 ++++++++++++++++++++++++++ > include/linux/pm_domain.h | 5 +++++ > 2 files changed, 31 insertions(+) > > diff --git a/drivers/base/power/domain.c b/drivers/base/power/domain.c > index 967bcf9d415e..84662d338188 100644 > --- a/drivers/base/power/domain.c > +++ b/drivers/base/power/domain.c > @@ -519,6 +519,31 @@ ktime_t dev_pm_genpd_get_next_hrtimer(struct device *dev) > } > EXPORT_SYMBOL_GPL(dev_pm_genpd_get_next_hrtimer); > > +/* > + * dev_pm_genpd_synced_poweroff - Next power off should be synchronous > + * > + * @dev: A device that is attached to the genpd. > + * > + * Allows a consumer of the genpd to notify the provider that the next power off > + * should be synchronous. > + * > + * It is assumed that the users guarantee that the genpd wouldn't be detached > + * while this routine is getting called. > + */ > +void dev_pm_genpd_synced_poweroff(struct device *dev) > +{ > + struct generic_pm_domain *genpd; > + > + genpd = dev_to_genpd_safe(dev); > + if (!genpd) > + return; > + > + genpd_lock(genpd); > + genpd->synced_poweroff = true; > + genpd_unlock(genpd); > +} > +EXPORT_SYMBOL_GPL(dev_pm_genpd_synced_poweroff); > + > static int _genpd_power_on(struct generic_pm_domain *genpd, bool timed) > { > unsigned int state_idx = genpd->state_idx; > @@ -562,6 +587,7 @@ static int _genpd_power_on(struct generic_pm_domain *genpd, bool timed) > > out: > raw_notifier_call_chain(&genpd->power_notifiers, GENPD_NOTIFY_ON, NULL); > + genpd->synced_poweroff = false; > return 0; > err: > raw_notifier_call_chain(&genpd->power_notifiers, GENPD_NOTIFY_OFF, > diff --git a/include/linux/pm_domain.h b/include/linux/pm_domain.h > index 1cd41bdf73cf..f776fb93eaa0 100644 > --- a/include/linux/pm_domain.h > +++ b/include/linux/pm_domain.h > @@ -136,6 +136,7 @@ struct generic_pm_domain { > unsigned int prepared_count; /* Suspend counter of prepared devices */ > unsigned int performance_state; /* Aggregated max performance state */ > cpumask_var_t cpus; /* A cpumask of the attached CPUs */ > + bool synced_poweroff; /* A consumer needs a synced poweroff */ > int (*power_off)(struct generic_pm_domain *domain); > int (*power_on)(struct generic_pm_domain *domain); > struct raw_notifier_head power_notifiers; /* Power on/off notifiers */ > @@ -235,6 +236,7 @@ int dev_pm_genpd_add_notifier(struct device *dev, struct notifier_block *nb); > int dev_pm_genpd_remove_notifier(struct device *dev); > void dev_pm_genpd_set_next_wakeup(struct device *dev, ktime_t next); > ktime_t dev_pm_genpd_get_next_hrtimer(struct device *dev); > +void dev_pm_genpd_synced_poweroff(struct device *dev); > > extern struct dev_power_governor simple_qos_governor; > extern struct dev_power_governor pm_domain_always_on_gov; > @@ -300,6 +302,9 @@ static inline ktime_t dev_pm_genpd_get_next_hrtimer(struct device *dev) > { > return KTIME_MAX; > } > +static inline void dev_pm_genpd_synced_poweroff(struct device *dev) > +{ } > + > #define simple_qos_governor (*(struct dev_power_governor *)(NULL)) > #define pm_domain_always_on_gov (*(struct dev_power_governor *)(NULL)) > #endif > -- > 2.7.4 >