linux-kernel - Re: [PATCH v2 1/3] PM: runtime: Wrapper macros for ACQUIRE()/ACQUIRE

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Message-ID: <aReN+P5UZTnS1Tww@lizhi-Precision-Tower-5810>
Date: Fri, 14 Nov 2025 15:15:52 -0500
From: Frank Li <Frank.li@....com>
To: "Rafael J. Wysocki" <rafael@...nel.org>
Cc: Linux PM <linux-pm@...r.kernel.org>,
	Linux ACPI <linux-acpi@...r.kernel.org>,
	Jonathan Cameron <jonathan.cameron@...wei.com>,
	Takashi Iwai <tiwai@...e.de>, LKML <linux-kernel@...r.kernel.org>,
	Zhang Qilong <zhangqilong3@...wei.com>, Dhruva Gole <d-gole@...com>,
	Dan Williams <dan.j.williams@...el.com>,
	Linux PCI <linux-pci@...r.kernel.org>,
	Bjorn Helgaas <helgaas@...nel.org>
Subject: Re: [PATCH v2 1/3] PM: runtime: Wrapper macros for
 ACQUIRE()/ACQUIRE_ERR()

On Thu, Nov 13, 2025 at 08:33:33PM +0100, Rafael J. Wysocki wrote:
> From: Rafael J. Wysocki <rafael.j.wysocki@...el.com>
>
> Add wrapper macros for ACQUIRE()/ACQUIRE_ERR() and runtime PM
> usage counter guards introduced recently: pm_runtime_active_try,
> pm_runtime_active_auto_try, pm_runtime_active_try_enabled, and
> pm_runtime_active_auto_try_enabled.
>
> The new macros should be more straightforward to use.
>
> For example, they can be used for rewriting a piece of code like below:
>
>         ACQUIRE(pm_runtime_active_try, pm)(dev);
>         if ((ret = ACQUIRE_ERR(pm_runtime_active_try, &pm)))
>                 return ret;
>
> in the following way:
>
>         PM_RUNTIME_ACQUIRE(dev, pm);
>         if ((ret = PM_RUNTIME_ACQUIRE_ERR(&pm)))
>                 return ret;
>
> If the original code does not care about the specific error code
> returned when attepmting to resume the device:
>
>         ACQUIRE(pm_runtime_active_try, pm)(dev);
>         if (ACQUIRE_ERR(pm_runtime_active_try, &pm))
>                 return -ENXIO;
>
> it may be changed like this:
>
>         PM_RUNTIME_ACQUIRE(dev, pm);
>         if (PM_RUNTIME_ACQUIRE_ERR(&pm))
>                 return -ENXIO;
>
> Link: https://lore.kernel.org/linux-pm/5068916.31r3eYUQgx@rafael.j.wysocki/
> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@...el.com>
> Reviewed-by: Dan Williams <dan.j.williams@...el.com>
> ---
>
> v1 -> v2:
>    * The new macros take the guard variable name as a parameter.
>    * The new ERR macro takes a guard variable pointer as a parameter (Dan).
>    * Added underscore prefix to the macro parameter names.

Reviewed-by: Frank Li <Frank.Li@....com>

>
> ---
>  include/linux/pm_runtime.h |   24 ++++++++++++++++++++++++
>  1 file changed, 24 insertions(+)
>
> --- a/include/linux/pm_runtime.h
> +++ b/include/linux/pm_runtime.h
> @@ -637,6 +637,30 @@ DEFINE_GUARD_COND(pm_runtime_active_auto
>  DEFINE_GUARD_COND(pm_runtime_active_auto, _try_enabled,
>  		  pm_runtime_resume_and_get(_T), _RET == 0)
>
> +/* ACQUIRE() wrapper macros for the guards defined above. */
> +
> +#define PM_RUNTIME_ACQUIRE(_dev, _var)			\
> +	ACQUIRE(pm_runtime_active_try, _var)(_dev)
> +
> +#define PM_RUNTIME_ACQUIRE_AUTOSUSPEND(_dev, _var)	\
> +	ACQUIRE(pm_runtime_active_auto_try, _var)(_dev)
> +
> +#define PM_RUNTIME_ACQUIRE_IF_ENABLED(_dev, _var)	\
> +	ACQUIRE(pm_runtime_active_try_enabled, _var)(_dev)
> +
> +#define PM_RUNTIME_ACQUIRE_IF_ENABLED_AUTOSUSPEND(_dev, _var)	\
> +	ACQUIRE(pm_runtime_active_auto_try_enabled, _var)(_dev)
> +
> +/*
> + * ACQUIRE_ERR() wrapper macro for guard pm_runtime_active.
> + *
> + * Always check PM_RUNTIME_ACQUIRE_ERR() after using one of the
> + * PM_RUNTIME_ACQUIRE*() macros defined above (yes, it can be used with
> + * any of them) and if it is nonzero, avoid accessing the given device.
> + */
> +#define PM_RUNTIME_ACQUIRE_ERR(_var_ptr)	\
> +	ACQUIRE_ERR(pm_runtime_active, _var_ptr)
> +
>  /**
>   * pm_runtime_put_sync - Drop device usage counter and run "idle check" if 0.
>   * @dev: Target device.
>
>
>