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Message-ID: <0daa7182d6600a24988d1c81cf8fe3c0c9487f52.camel@pengutronix.de>
Subject: Re: [PATCH v10 03/11] drm/etnaviv: Add dedicated functions to
 create and destroy platform device
From:   Lucas Stach <l.stach@pengutronix.de>
To:     Sui Jingfeng <18949883232@163.com>,
        Russell King <linux+etnaviv@armlinux.org.uk>,
        Christian Gmeiner <christian.gmeiner@gmail.com>,
        David Airlie <airlied@gmail.com>,
        Daniel Vetter <daniel@ffwll.ch>
Cc:     Sui Jingfeng <suijingfeng@loongson.cn>,
        linux-kernel@vger.kernel.org, dri-devel@lists.freedesktop.org,
        etnaviv@lists.freedesktop.org,
        Philipp Zabel <p.zabel@pengutronix.de>,
        Bjorn Helgaas <bhelgaas@google.com>
Date:   Wed, 21 Jun 2023 11:15:00 +0200
In-Reply-To: <20230620094716.2231414-4-18949883232@163.com>
References: <20230620094716.2231414-1-18949883232@163.com>
         <20230620094716.2231414-4-18949883232@163.com>
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Am Dienstag, dem 20.06.2023 um 17:47 +0800 schrieb Sui Jingfeng:
> From: Sui Jingfeng <suijingfeng@loongson.cn>
> 
> Also rename the virtual master platform device as etnaviv_platform_device,
> for better reflection that it is a platform device, not a DRM device.
> 
> Another benefit is that we no longer need to call of_node_put() for three
> different cases, Instead, we only need to call it once.
> 
> Cc: Lucas Stach <l.stach@pengutronix.de>
> Cc: Christian Gmeiner <christian.gmeiner@gmail.com>
> Cc: Philipp Zabel <p.zabel@pengutronix.de>
> Cc: Bjorn Helgaas <bhelgaas@google.com>
> Cc: Daniel Vetter <daniel@ffwll.ch>
> Signed-off-by: Sui Jingfeng <suijingfeng@loongson.cn>
> ---
>  drivers/gpu/drm/etnaviv/etnaviv_drv.c | 56 +++++++++++++++++++--------
>  1 file changed, 39 insertions(+), 17 deletions(-)
> 
> diff --git a/drivers/gpu/drm/etnaviv/etnaviv_drv.c b/drivers/gpu/drm/etnaviv/etnaviv_drv.c
> index 31a7f59ccb49..cec005035d0e 100644
> --- a/drivers/gpu/drm/etnaviv/etnaviv_drv.c
> +++ b/drivers/gpu/drm/etnaviv/etnaviv_drv.c
> @@ -656,12 +656,44 @@ static struct platform_driver etnaviv_platform_driver = {
>  	},
>  };
>  
> -static struct platform_device *etnaviv_drm;
> +static struct platform_device *etnaviv_platform_device;
>  
> -static int __init etnaviv_init(void)
> +static int etnaviv_create_platform_device(const char *name,
> +					  struct platform_device **ppdev)

As the platform device is a global static variable, there is no need to
push it through the parameters of this function. Just use the global
variable directly in this function.

>  {
>  	struct platform_device *pdev;
>  	int ret;
> +
> +	pdev = platform_device_alloc(name, PLATFORM_DEVID_NONE);
> +	if (!pdev)
> +		return -ENOMEM;
> +
> +	ret = platform_device_add(pdev);
> +	if (ret) {
> +		platform_device_put(pdev);
> +		return ret;
> +	}
> +
> +	*ppdev = pdev;
> +
> +	return 0;
> +}
> +
> +static void etnaviv_destroy_platform_device(struct platform_device **ppdev)
> +{
> +	struct platform_device *pdev = *ppdev;

Same here, just use the global variable directly.

Regards,
Lucas

> +
> +	if (!pdev)
> +		return;
> +
> +	platform_device_unregister(pdev);
> +
> +	*ppdev = NULL;
> +}
> +
> +static int __init etnaviv_init(void)
> +{
> +	int ret;
>  	struct device_node *np;
>  
>  	etnaviv_validate_init();
> @@ -681,23 +713,13 @@ static int __init etnaviv_init(void)
>  	for_each_compatible_node(np, NULL, "vivante,gc") {
>  		if (!of_device_is_available(np))
>  			continue;
> +		of_node_put(np);
>  
> -		pdev = platform_device_alloc("etnaviv", PLATFORM_DEVID_NONE);
> -		if (!pdev) {
> -			ret = -ENOMEM;
> -			of_node_put(np);
> -			goto unregister_platform_driver;
> -		}
> -
> -		ret = platform_device_add(pdev);
> -		if (ret) {
> -			platform_device_put(pdev);
> -			of_node_put(np);
> +		ret = etnaviv_create_platform_device("etnaviv",
> +						     &etnaviv_platform_device);
> +		if (ret)
>  			goto unregister_platform_driver;
> -		}
>  
> -		etnaviv_drm = pdev;
> -		of_node_put(np);
>  		break;
>  	}
>  
> @@ -713,7 +735,7 @@ module_init(etnaviv_init);
>  
>  static void __exit etnaviv_exit(void)
>  {
> -	platform_device_unregister(etnaviv_drm);
> +	etnaviv_destroy_platform_device(&etnaviv_platform_device);
>  	platform_driver_unregister(&etnaviv_platform_driver);
>  	platform_driver_unregister(&etnaviv_gpu_driver);
>  }