Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751299AbaKFWaU (ORCPT ); Thu, 6 Nov 2014 17:30:20 -0500 Received: from v094114.home.net.pl ([79.96.170.134]:51242 "HELO v094114.home.net.pl" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with SMTP id S1751167AbaKFWaT (ORCPT ); Thu, 6 Nov 2014 17:30:19 -0500 From: "Rafael J. Wysocki" To: Krzysztof Kozlowski Cc: Len Brown , Pavel Machek , Russell King , Dan Williams , Vinod Koul , Ulf Hansson , Alan Stern , linux-pm@vger.kernel.org, linux-kernel@vger.kernel.org, dmaengine@vger.kernel.org, Lars-Peter Clausen , Michal Simek , Kevin Hilman , Laurent Pinchart , Kyungmin Park , Marek Szyprowski , Bartlomiej Zolnierkiewicz Subject: Re: [PATCH v10 1/5] PM / Runtime: Allow accessing irq_safe if no PM_RUNTIME Date: Thu, 06 Nov 2014 23:51:06 +0100 Message-ID: <2475860.cssHTQVJGf@vostro.rjw.lan> User-Agent: KMail/4.11.5 (Linux/3.16.0-rc5+; KDE/4.11.5; x86_64; ; ) In-Reply-To: <1415263010-7992-2-git-send-email-k.kozlowski@samsung.com> References: <1415263010-7992-1-git-send-email-k.kozlowski@samsung.com> <1415263010-7992-2-git-send-email-k.kozlowski@samsung.com> 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, November 06, 2014 09:36:46 AM Krzysztof Kozlowski wrote: > Some drivers (e.g. bus drivers) may want to check if power.irq_safe was > called by child driver, regardless of CONFIG_PM_RUNTIME. > > An example scenario is amba/bus.c and dma/pl330.c drivers. The runtime > suspend/resume callbacks in amba bus driver act differently if irq_safe > was set by child driver (in irq_safe mode bus clock is only disabled). > > The pl330 driver sets irq_safe and assumes that amba bus driver will > only disable the clock in runtime PM. So in system sleep suspend > callback the pl330 driver unprepares the clock after calling > pm_runtime_force_suspend(). > > However inconsistency would appear if CONFIG_PM_RUNTIME is not set and > child drivers do not want the irq_safe runtime PM. In such case amba bus > driver still has to know whether child driver wanted irq_safe - by > looking at dev->power.irq_safe field. > > Signed-off-by: Krzysztof Kozlowski > --- > include/linux/pm.h | 2 +- > include/linux/pm_runtime.h | 5 ++++- > 2 files changed, 5 insertions(+), 2 deletions(-) > > diff --git a/include/linux/pm.h b/include/linux/pm.h > index 383fd68aaee1..b05fa954f50d 100644 > --- a/include/linux/pm.h > +++ b/include/linux/pm.h > @@ -566,6 +566,7 @@ struct dev_pm_info { > bool ignore_children:1; > bool early_init:1; /* Owned by the PM core */ > bool direct_complete:1; /* Owned by the PM core */ > + unsigned int irq_safe:1; /* PM runtime */ > spinlock_t lock; > #ifdef CONFIG_PM_SLEEP > struct list_head entry; > @@ -590,7 +591,6 @@ struct dev_pm_info { > unsigned int run_wake:1; > unsigned int runtime_auto:1; > unsigned int no_callbacks:1; > - unsigned int irq_safe:1; > unsigned int use_autosuspend:1; > unsigned int timer_autosuspends:1; > unsigned int memalloc_noio:1; Well, that is a good reason to introduce a wrapper around power.irq_safe in my view. And define the wrapper so that it always returns false for CONFIG_PM_RUNTIME unset. This way not only you wouldn't need to move the flag from under the #ifdef, but also you would make the compiler skip the relevant pieces of code entiretly for CONFIG_PM_RUNTIME unset. > diff --git a/include/linux/pm_runtime.h b/include/linux/pm_runtime.h > index 367f49b9a1c9..d94a65662a60 100644 > --- a/include/linux/pm_runtime.h > +++ b/include/linux/pm_runtime.h > @@ -166,7 +166,10 @@ static inline bool pm_runtime_suspended_if_enabled(struct device *dev) { return > static inline bool pm_runtime_enabled(struct device *dev) { return false; } > > static inline void pm_runtime_no_callbacks(struct device *dev) {} > -static inline void pm_runtime_irq_safe(struct device *dev) {} > +static inline void pm_runtime_irq_safe(struct device *dev) > +{ > + dev->power.irq_safe = 1; > +} > > static inline bool pm_runtime_callbacks_present(struct device *dev) { return false; } > static inline void pm_runtime_mark_last_busy(struct device *dev) {} > -- I speak only for myself. Rafael J. Wysocki, Intel Open Source Technology Center. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/