linux-kernel - Re: [PATCH] pinctrl: pinctrl-intel: move gpio suspend/resume to noirq phase

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Message-ID: <20190408124348.GQ9224@smile.fi.intel.com>
Date:   Mon, 8 Apr 2019 15:43:48 +0300
From:   Andy Shevchenko <andriy.shevchenko@...ux.intel.com>
To:     Binbin Wu <binbin.wu@...el.com>
Cc:     mika.westerberg@...ux.intel.com, linux-kernel@...r.kernel.org,
        linux-gpio@...r.kernel.org
Subject: Re: [PATCH] pinctrl: pinctrl-intel: move gpio suspend/resume to
 noirq phase

On Mon, Apr 08, 2019 at 06:49:26PM +0800, Binbin Wu wrote:
> In current driver, SET_LATE_SYSTEM_SLEEP_PM_OPS is used to install the
> callbacks for suspend/resume.
> GPIO pin may be used as the interrupt pin by some device. However, using
> SET_LATE_SYSTEM_SLEEP_PM_OPS() to install the callbacks, the resume
> callback is called after resume_device_irqs(). Unintended interrupts may
> arrive due to resuming device irqs first, but the GPIO controller is not
> properly restored.
> 
> Normally, for a SMP system, there are multiple cores, so even when there are
> unintended interrupts, BSP gets the chance to init the gpio chip soon.

gpio -> GPIO.
(If Mika is okay with patch content, I may fix this when applying)

> But when there is only 1 core is active (other cores are offlined or
> single core) during resume, it is more easily to observe the unintended
> interrupts.
> 
> This patch renames the suspend/resume function by adding suffix "_noirq",
> and installs the callbacks using SET_NOIRQ_SYSTEM_SLEEP_PM_OPS().
> 
> Signed-off-by: Binbin Wu <binbin.wu@...el.com>
> ---
>  drivers/pinctrl/intel/pinctrl-intel.c |  8 ++++----
>  drivers/pinctrl/intel/pinctrl-intel.h | 11 ++++++-----
>  2 files changed, 10 insertions(+), 9 deletions(-)
> 
> diff --git a/drivers/pinctrl/intel/pinctrl-intel.c b/drivers/pinctrl/intel/pinctrl-intel.c
> index 3b18181..70638b7 100644
> --- a/drivers/pinctrl/intel/pinctrl-intel.c
> +++ b/drivers/pinctrl/intel/pinctrl-intel.c
> @@ -1466,7 +1466,7 @@ static bool intel_pinctrl_should_save(struct intel_pinctrl *pctrl, unsigned int
>  	return false;
>  }
>  
> -int intel_pinctrl_suspend(struct device *dev)
> +int intel_pinctrl_suspend_noirq(struct device *dev)
>  {
>  	struct intel_pinctrl *pctrl = dev_get_drvdata(dev);
>  	struct intel_community_context *communities;
> @@ -1505,7 +1505,7 @@ int intel_pinctrl_suspend(struct device *dev)
>  
>  	return 0;
>  }
> -EXPORT_SYMBOL_GPL(intel_pinctrl_suspend);
> +EXPORT_SYMBOL_GPL(intel_pinctrl_suspend_noirq);
>  
>  static void intel_gpio_irq_init(struct intel_pinctrl *pctrl)
>  {
> @@ -1527,7 +1527,7 @@ static void intel_gpio_irq_init(struct intel_pinctrl *pctrl)
>  	}
>  }
>  
> -int intel_pinctrl_resume(struct device *dev)
> +int intel_pinctrl_resume_noirq(struct device *dev)
>  {
>  	struct intel_pinctrl *pctrl = dev_get_drvdata(dev);
>  	const struct intel_community_context *communities;
> @@ -1589,7 +1589,7 @@ int intel_pinctrl_resume(struct device *dev)
>  
>  	return 0;
>  }
> -EXPORT_SYMBOL_GPL(intel_pinctrl_resume);
> +EXPORT_SYMBOL_GPL(intel_pinctrl_resume_noirq);
>  #endif
>  
>  MODULE_AUTHOR("Mathias Nyman <mathias.nyman@...ux.intel.com>");
> diff --git a/drivers/pinctrl/intel/pinctrl-intel.h b/drivers/pinctrl/intel/pinctrl-intel.h
> index b8a07d37..a8e958f 100644
> --- a/drivers/pinctrl/intel/pinctrl-intel.h
> +++ b/drivers/pinctrl/intel/pinctrl-intel.h
> @@ -177,13 +177,14 @@ int intel_pinctrl_probe_by_hid(struct platform_device *pdev);
>  int intel_pinctrl_probe_by_uid(struct platform_device *pdev);
>  
>  #ifdef CONFIG_PM_SLEEP
> -int intel_pinctrl_suspend(struct device *dev);
> -int intel_pinctrl_resume(struct device *dev);
> +int intel_pinctrl_suspend_noirq(struct device *dev);
> +int intel_pinctrl_resume_noirq(struct device *dev);
>  #endif
>  
> -#define INTEL_PINCTRL_PM_OPS(_name)						  \
> -const struct dev_pm_ops _name = {						  \
> -	SET_LATE_SYSTEM_SLEEP_PM_OPS(intel_pinctrl_suspend, intel_pinctrl_resume) \
> +#define INTEL_PINCTRL_PM_OPS(_name)					\
> +const struct dev_pm_ops _name = {					\
> +	SET_NOIRQ_SYSTEM_SLEEP_PM_OPS(intel_pinctrl_suspend_noirq,	\
> +				      intel_pinctrl_resume_noirq)	\
>  }
>  
>  #endif /* PINCTRL_INTEL_H */
> -- 
> 2.7.4
> 

-- 
With Best Regards,
Andy Shevchenko