Re: [PATCH v1 1/3] PM: runtime: Wrapper macros for ACQUIRE()/ACQUIRE_ERR()

Frank Li
2025-11-10T16:07:42Z

On Fri, Nov 07, 2025 at 07:39:55PM +0100, Rafael J. Wysocki wrote:
> From: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
>
> Add several 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 are simpler and should be more straightforward to use.
> Moreover, they do not expose internal details that are not strictly
> related to the code using the macros.
>
> 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);
> if ((ret = PM_RUNTIME_ACQUIRE_ERR))

Personally, I feel like PM_RUNTIME_ACQUIRE_ERR hide too much informaiton.

There are not clear connection between PM_RUNTIME_ACQUIRE and
PM_RUNTIME_ACQUIRE_ERR. but previous code, the 'pm' is good connector.

Frank
> return ret;
>
> If the original code does not care about the specific error code
> returned when attempting 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);
> if (PM_RUNTIME_ACQUIRE_ERR)
> return -ENXIO;
>
> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
> ---
> include/linux/pm_runtime.h | 55 +++++++++++++++++++++++++++++++++++++++++++++
> 1 file changed, 55 insertions(+)
>
> --- a/include/linux/pm_runtime.h
> +++ b/include/linux/pm_runtime.h
> @@ -637,6 +637,61 @@ 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.
> + *
> + * The tagged __PM_RUNTIME_ACQUIRE*() variants are for the cases in which two or
> + * more of these macros are used in the same scope and the tags are necessary to
> + * distinguish the internal guard variables from each other. Don't do that
> + * unless you have to. No, really. If they are needed, using simple tags is
> + * recommended (for example, individual digits or letters).
> + *
> + * The simpler PM_RUNTIME_ACQUIRE*() variants are wrappers around the
> + * corresponding __PM_RUNTIME_ACQUIRE*() that use the underline character
> + * as a (special) tag. They should be suitable for the vast majority of use
> + * cases.
> + *
> + * Don't mix up PM_RUNTIME_ACQUIRE*() with __PM_RUNTIME_ACQUIRE*() even though
> + * that may work.
> + */
> +#define __PM_RUNTIME_ACQUIRE(dev, tag) \
> + ACQUIRE(pm_runtime_active_try, _pm_runtime_guard_var_##tag)(dev)
> +
> +#define PM_RUNTIME_ACQUIRE(dev) \
> + __PM_RUNTIME_ACQUIRE(dev, _)
> +
> +#define __PM_RUNTIME_ACQUIRE_AUTOSUSPEND(dev, tag) \
> + ACQUIRE(pm_runtime_active_auto_try, _pm_runtime_guard_var_##tag)(dev)
> +
> +#define PM_RUNTIME_ACQUIRE_AUTOSUSPEND(dev) \
> + __PM_RUNTIME_ACQUIRE_AUTOSUSPEND(dev, _)
> +
> +#define __PM_RUNTIME_ACQUIRE_ENABLED(dev, tag) \
> + ACQUIRE(pm_runtime_active_try_enabled, _pm_runtime_guard_var_##tag)(dev)
> +
> +#define PM_RUNTIME_ACQUIRE_ENABLED(dev) \
> + __PM_RUNTIME_ACQUIRE_ENABLED(dev, _)
> +
> +#define __PM_RUNTIME_ACQUIRE_ENABLED_AUTOSUSPEND(dev, tag) \
> + ACQUIRE(pm_runtime_active_auto_try_enabled, _pm_runtime_guard_var_##tag)(dev)
> +
> +#define PM_RUNTIME_ACQUIRE_ENABLED_AUTOSUSPEND(dev) \
> + __PM_RUNTIME_ACQUIRE_ENABLED_AUTOSUSPEND(dev, _)
> +
> +/*
> + * ACQUIRE_ERR() wrapper macros for guard pm_runtime_active.
> + *
> + * Always check __PM_RUNTIME_ACQUIRE_ERR() with a matching tag after using one
> + * of the tagged __PM_RUNTIME_ACQUIRE*() macros defined above (yes, it can be
> + * used with any of them) and avoid accessing the given device if it is nonzero.
> + * Analogously, always check PM_RUNTIME_ACQUIRE_ERR after using any of the
> + * simpler PM_RUNTIME_ACQUIRE*() macros.
> + */
> +#define __PM_RUNTIME_ACQUIRE_ERR(tag) \
> + ACQUIRE_ERR(pm_runtime_active, &_pm_runtime_guard_var_##tag)
> +
> +#define PM_RUNTIME_ACQUIRE_ERR __PM_RUNTIME_ACQUIRE_ERR(_)
> +
> /**
> * pm_runtime_put_sync - Drop device usage counter and run "idle check" if 0.
> * @dev: Target device.
>
>
>