Re: [PATCH v1 2/4] usb: ehci-exynos: Switch from CONFIG_PM guards to pm_ptr()

[Alan Stern]

On Sat, Mar 02, 2024 at 01:08:09AM +0530, Anand Moon wrote:
> Use the new PM macros for the suspend and resume functions to be
> automatically dropped by the compiler when CONFIG_PM are disabled,
> without having to use #ifdef guards. If CONFIG_PM unused,
> they will simply be discarded by the compiler.
> 
> Use RUNTIME_PM_OPS runtime macro for suspend/resume function.
> 
> Signed-off-by: Anand Moon <linux.amoon@xxxxxxxxx>
> ---
>  drivers/usb/host/ehci-exynos.c | 10 ++--------
>  1 file changed, 2 insertions(+), 8 deletions(-)
> 
> diff --git a/drivers/usb/host/ehci-exynos.c b/drivers/usb/host/ehci-exynos.c
> index 05aa3d9c2a3b..4676f45655cd 100644
> --- a/drivers/usb/host/ehci-exynos.c
> +++ b/drivers/usb/host/ehci-exynos.c
> @@ -234,7 +234,6 @@ static void exynos_ehci_remove(struct platform_device *pdev)
>  	usb_put_hcd(hcd);
>  }
>  
> -#ifdef CONFIG_PM
>  static int exynos_ehci_suspend(struct device *dev)
>  {
>  	struct usb_hcd *hcd = dev_get_drvdata(dev);
> @@ -268,14 +267,9 @@ static int exynos_ehci_resume(struct device *dev)
>  	ehci_resume(hcd, false);
>  	return 0;
>  }
> -#else
> -#define exynos_ehci_suspend	NULL
> -#define exynos_ehci_resume	NULL
> -#endif

Doesn't this now generate warnings about functions being defined but not 
used when you build with CONFIG_PM disabled?

Alan Stern

>  
>  static const struct dev_pm_ops exynos_ehci_pm_ops = {
> -	.suspend	= exynos_ehci_suspend,
> -	.resume		= exynos_ehci_resume,
> +	RUNTIME_PM_OPS(exynos_ehci_suspend, exynos_ehci_resume, NULL)
>  };
>  
>  #ifdef CONFIG_OF
> @@ -292,7 +286,7 @@ static struct platform_driver exynos_ehci_driver = {
>  	.shutdown	= usb_hcd_platform_shutdown,
>  	.driver = {
>  		.name	= "exynos-ehci",
> -		.pm	= &exynos_ehci_pm_ops,
> +		.pm	= pm_ptr(&exynos_ehci_pm_ops),
>  		.of_match_table = of_match_ptr(exynos_ehci_match),
>  	}
>  };
> -- 
> 2.43.0
>