From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752015AbcFIW5A (ORCPT ); Thu, 9 Jun 2016 18:57:00 -0400 Received: from mail-pa0-f53.google.com ([209.85.220.53]:32960 "EHLO mail-pa0-f53.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750792AbcFIW46 (ORCPT ); Thu, 9 Jun 2016 18:56:58 -0400 From: Kevin Hilman To: Jon Hunter Cc: Grygorii Strashko , Thomas Gleixner , Jason Cooper , Marc Zyngier , Rob Herring , Pawel Moll , "Mark Rutland" , Ian Campbell , Kumar Gala , Stephen Warren , Thierry Reding , Geert Uytterhoeven , Lars-Peter Clausen , Linus Walleij , , , Subject: Re: [PATCH V5 4/9] genirq: Add runtime power management support for IRQ chips Organization: BayLibre References: <1465214023-8299-1-git-send-email-jonathanh@nvidia.com> <1465214023-8299-5-git-send-email-jonathanh@nvidia.com> <57558523.9070700@ti.com> <57558909.9090309@nvidia.com> <57558A83.1000603@ti.com> <5755917A.7070704@nvidia.com> Date: Thu, 09 Jun 2016 15:56:54 -0700 In-Reply-To: <5755917A.7070704@nvidia.com> (Jon Hunter's message of "Mon, 6 Jun 2016 16:06:34 +0100") Message-ID: <7htwh2c6o9.fsf@baylibre.com> User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/24.5 (gnu/linux) MIME-Version: 1.0 Content-Type: text/plain Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Jon Hunter writes: > On 06/06/16 15:36, Grygorii Strashko wrote: >> On 06/06/2016 05:30 PM, Jon Hunter wrote: >>> >>> On 06/06/16 15:13, Grygorii Strashko wrote: >>>> On 06/06/2016 02:53 PM, Jon Hunter wrote: >>>>> Some IRQ chips may be located in a power domain outside of the CPU >>>>> subsystem and hence will require device specific runtime power >>>>> management. In order to support such IRQ chips, add a pointer for a >>>>> device structure to the irq_chip structure, and if this pointer is >>>>> populated by the IRQ chip driver and CONFIG_PM is selected in the kernel >>>>> configuration, then the pm_runtime_get/put APIs for this chip will be >>>>> called when an IRQ is requested/freed, respectively. >>>>> >>>>> Signed-off-by: Jon Hunter >>>>> Reviewed-by: Kevin Hilman >>>>> Reviewed-by: Marc Zyngier >>>>> --- >>>>> include/linux/irq.h | 4 ++++ >>>>> kernel/irq/chip.c | 35 +++++++++++++++++++++++++++++++++++ >>>>> kernel/irq/internals.h | 1 + >>>>> kernel/irq/manage.c | 31 ++++++++++++++++++++++++++++++- >>>>> 4 files changed, 70 insertions(+), 1 deletion(-) >>>>> >>>>> diff --git a/include/linux/irq.h b/include/linux/irq.h >>>>> index 4d758a7c604a..6c92a847394d 100644 >>>>> --- a/include/linux/irq.h >>>>> +++ b/include/linux/irq.h >>>>> @@ -315,6 +315,7 @@ static inline irq_hw_number_t irqd_to_hwirq(struct irq_data *d) >>>>> /** >>>>> * struct irq_chip - hardware interrupt chip descriptor >>>>> * >>>>> + * @parent_device: pointer to parent device for irqchip >>>>> * @name: name for /proc/interrupts >>>>> * @irq_startup: start up the interrupt (defaults to ->enable if NULL) >>>>> * @irq_shutdown: shut down the interrupt (defaults to ->disable if NULL) >>>>> @@ -354,6 +355,7 @@ static inline irq_hw_number_t irqd_to_hwirq(struct irq_data *d) >>>>> * @flags: chip specific flags >>>>> */ >>>>> struct irq_chip { >>>>> + struct device *parent_device; >>>>> const char *name; >>>>> unsigned int (*irq_startup)(struct irq_data *data); >>>>> void (*irq_shutdown)(struct irq_data *data); >>>>> @@ -488,6 +490,8 @@ extern void handle_bad_irq(struct irq_desc *desc); >>>>> extern void handle_nested_irq(unsigned int irq); >>>>> >>>>> extern int irq_chip_compose_msi_msg(struct irq_data *data, struct msi_msg *msg); >>>>> +extern int irq_chip_pm_get(struct irq_data *data); >>>>> +extern int irq_chip_pm_put(struct irq_data *data); >>>>> #ifdef CONFIG_IRQ_DOMAIN_HIERARCHY >>>>> extern void irq_chip_enable_parent(struct irq_data *data); >>>>> extern void irq_chip_disable_parent(struct irq_data *data); >>>>> diff --git a/kernel/irq/chip.c b/kernel/irq/chip.c >>>>> index 2f9f2b0e79f2..b09226e895c7 100644 >>>>> --- a/kernel/irq/chip.c >>>>> +++ b/kernel/irq/chip.c >>>>> @@ -1093,3 +1093,38 @@ int irq_chip_compose_msi_msg(struct irq_data *data, struct msi_msg *msg) >>>>> >>>>> return 0; >>>>> } >>>>> + >>>>> +/** >>>>> + * irq_chip_pm_get - Enable power for an IRQ chip >>>>> + * @data: Pointer to interrupt specific data >>>>> + * >>>>> + * Enable the power to the IRQ chip referenced by the interrupt data >>>>> + * structure. >>>>> + */ >>>>> +int irq_chip_pm_get(struct irq_data *data) >>>>> +{ >>>>> + int retval = 0; >>>>> + >>>>> + if (IS_ENABLED(CONFIG_PM) && data->chip->parent_device) >>>>> + retval = pm_runtime_get_sync(data->chip->parent_device); >>>> >>>> Sry, for the late comment - above require pm_runtime_put_noidle(data->chip->parent_device); >>>> in case of failure. >>> >>> No problem. Sorry, can you elaborate? I am not familiar with the >>> _put_noidle(). >>> >> >> Question here in use counter - pm_runtime_get_sync() will increment usage_count >> always and it will not decrement it in case of failure. >> pm_runtime_put_noidle() expected to restore usage_count state (-1). > > Thanks was not aware of that. > > Kevin, Marc, given that you have reviewed this one, are you ok with the > above change Grygorii is proposing? Yes, that's the right thing to do on error. Kevin