linux-kernel - Re: [PATCH v1] PM: runtime: Fix conditional guard definitions

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Message-ID: <20251020164829.00000f53@huawei.com>
Date: Mon, 20 Oct 2025 16:48:29 +0100
From: Jonathan Cameron <jonathan.cameron@...wei.com>
To: "Rafael J. Wysocki" <rafael@...nel.org>
CC: Linux PM <linux-pm@...r.kernel.org>, Takashi Iwai <tiwai@...e.de>, LKML
	<linux-kernel@...r.kernel.org>, Linux PCI <linux-pci@...r.kernel.org>, "Alex
 Williamson" <alex.williamson@...hat.com>, Bjorn Helgaas <helgaas@...nel.org>,
	Zhang Qilong <zhangqilong3@...wei.com>, Ulf Hansson <ulf.hansson@...aro.org>,
	Frank Li <Frank.Li@....com>, Dhruva Gole <d-gole@...com>, Dan Williams
	<dan.j.williams@...el.com>
Subject: Re: [PATCH v1] PM: runtime: Fix conditional guard definitions

On Mon, 20 Oct 2025 17:03:28 +0200
"Rafael J. Wysocki" <rafael@...nel.org> wrote:

> From: Rafael J. Wysocki <rafael.j.wysocki@...el.com>
> 
> Since pm_runtime_get_active() returns 0 on success, all of the
> DEFINE_GUARD_COND() macros in pm_runtime.h need the "_RET == 0"
> condition at the end of the argument list or they would not work
> correctly.
> 
> Fixes: 9a0abc39450a ("PM: runtime: Add auto-cleanup macros for "resume and get" operations")
> Reported-by: kernel test robot <lkp@...el.com>
> Link: https://lore.kernel.org/linux-pm/202510191529.BCyjKlLQ-lkp@intel.com/
> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@...el.com>
Makes sense.

Reviewed-by: Jonathan Cameron <jonathan.cameron@...wei.com>

These macros are a bit awkward to get right - I'd forgotten the oddity that
conditional locks use != 0 to mean the lock was taken.


> ---
>  include/linux/pm_runtime.h |    8 ++++----
>  1 file changed, 4 insertions(+), 4 deletions(-)
> 
> --- a/include/linux/pm_runtime.h
> +++ b/include/linux/pm_runtime.h
> @@ -629,13 +629,13 @@ DEFINE_GUARD(pm_runtime_active_auto, str
>   * device.
>   */
>  DEFINE_GUARD_COND(pm_runtime_active, _try,
> -		  pm_runtime_get_active(_T, RPM_TRANSPARENT))
> +		  pm_runtime_get_active(_T, RPM_TRANSPARENT), _RET == 0)
>  DEFINE_GUARD_COND(pm_runtime_active, _try_enabled,
> -		  pm_runtime_resume_and_get(_T))
> +		  pm_runtime_resume_and_get(_T), _RET == 0)
>  DEFINE_GUARD_COND(pm_runtime_active_auto, _try,
> -		  pm_runtime_get_active(_T, RPM_TRANSPARENT))
> +		  pm_runtime_get_active(_T, RPM_TRANSPARENT), _RET == 0)
>  DEFINE_GUARD_COND(pm_runtime_active_auto, _try_enabled,
> -		  pm_runtime_resume_and_get(_T))
> +		  pm_runtime_resume_and_get(_T), _RET == 0)
>  
>  /**
>   * pm_runtime_put_sync - Drop device usage counter and run "idle check" if 0.
> 
> 
>