linux-kernel - Re: [PATCH 09/11] usb: dwc3: rtk: use scoped device node handling to simplify error paths

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Message-ID: <20240827014338.o3hjjxhwd5x7cbly@synopsys.com>
Date: Tue, 27 Aug 2024 01:43:41 +0000
From: Thinh Nguyen <Thinh.Nguyen@...opsys.com>
To: Krzysztof Kozlowski <krzysztof.kozlowski@...aro.org>
CC: Patrice Chotard <patrice.chotard@...s.st.com>,
        Thinh Nguyen <Thinh.Nguyen@...opsys.com>,
        Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
        Shawn Guo <shawnguo@...nel.org>, Sascha Hauer <s.hauer@...gutronix.de>,
        Pengutronix Kernel Team <kernel@...gutronix.de>,
        Fabio Estevam <festevam@...il.com>,
        Michal Simek <michal.simek@....com>,
        "linux-arm-kernel@...ts.infradead.org" <linux-arm-kernel@...ts.infradead.org>,
        "linux-usb@...r.kernel.org" <linux-usb@...r.kernel.org>,
        "linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>,
        "imx@...ts.linux.dev" <imx@...ts.linux.dev>,
        "linux-arm-msm@...r.kernel.org" <linux-arm-msm@...r.kernel.org>
Subject: Re: [PATCH 09/11] usb: dwc3: rtk: use scoped device node handling to
 simplify error paths

On Wed, Aug 14, 2024, Krzysztof Kozlowski wrote:
> Obtain the device node reference with scoped/cleanup.h to reduce error
> handling and make the code a bit simpler.
> 
> Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@...aro.org>
> ---
>  drivers/usb/dwc3/dwc3-rtk.c | 19 +++++++------------
>  1 file changed, 7 insertions(+), 12 deletions(-)
> 
> diff --git a/drivers/usb/dwc3/dwc3-rtk.c b/drivers/usb/dwc3/dwc3-rtk.c
> index 3cd6b184551c..1e3ec2084286 100644
> --- a/drivers/usb/dwc3/dwc3-rtk.c
> +++ b/drivers/usb/dwc3/dwc3-rtk.c
> @@ -6,6 +6,7 @@
>   *
>   */
>  
> +#include <linux/cleanup.h>
>  #include <linux/module.h>
>  #include <linux/kernel.h>
>  #include <linux/platform_device.h>
> @@ -173,23 +174,20 @@ static const char *const speed_names[] = {
>  
>  static enum usb_device_speed __get_dwc3_maximum_speed(struct device_node *np)
>  {
> -	struct device_node *dwc3_np;
>  	const char *maximum_speed;
>  	int ret;
>  
> -	dwc3_np = of_get_compatible_child(np, "snps,dwc3");
> +	struct device_node *dwc3_np __free(device_node) = of_get_compatible_child(np,
> +										  "snps,dwc3");
>  	if (!dwc3_np)
>  		return USB_SPEED_UNKNOWN;
>  
>  	ret = of_property_read_string(dwc3_np, "maximum-speed", &maximum_speed);
>  	if (ret < 0)
> -		goto out;
> +		return ret;
>  
>  	ret = match_string(speed_names, ARRAY_SIZE(speed_names), maximum_speed);
>  
> -out:
> -	of_node_put(dwc3_np);
> -
>  	return (ret < 0) ? USB_SPEED_UNKNOWN : ret;
>  }
>  
> @@ -276,7 +274,6 @@ static int dwc3_rtk_probe_dwc3_core(struct dwc3_rtk *rtk)
>  	struct device_node *node = dev->of_node;
>  	struct platform_device *dwc3_pdev;
>  	struct device *dwc3_dev;
> -	struct device_node *dwc3_node;
>  	enum usb_dr_mode dr_mode;
>  	int ret = 0;
>  
> @@ -290,7 +287,8 @@ static int dwc3_rtk_probe_dwc3_core(struct dwc3_rtk *rtk)
>  		return ret;
>  	}
>  
> -	dwc3_node = of_get_compatible_child(node, "snps,dwc3");
> +	struct device_node *dwc3_node __free(device_node) = of_get_compatible_child(node,
> +										    "snps,dwc3");
>  	if (!dwc3_node) {
>  		dev_err(dev, "failed to find dwc3 core node\n");
>  		ret = -ENODEV;
> @@ -301,7 +299,7 @@ static int dwc3_rtk_probe_dwc3_core(struct dwc3_rtk *rtk)
>  	if (!dwc3_pdev) {
>  		dev_err(dev, "failed to find dwc3 core platform_device\n");
>  		ret = -ENODEV;
> -		goto err_node_put;
> +		goto depopulate;
>  	}
>  
>  	dwc3_dev = &dwc3_pdev->dev;
> @@ -343,14 +341,11 @@ static int dwc3_rtk_probe_dwc3_core(struct dwc3_rtk *rtk)
>  	switch_usb2_role(rtk, rtk->cur_role);
>  
>  	platform_device_put(dwc3_pdev);
> -	of_node_put(dwc3_node);
>  
>  	return 0;
>  
>  err_pdev_put:
>  	platform_device_put(dwc3_pdev);
> -err_node_put:
> -	of_node_put(dwc3_node);
>  depopulate:
>  	of_platform_depopulate(dev);
>  
> 
> -- 
> 2.43.0
> 

Acked-by: Thinh Nguyen <Thinh.Nguyen@...opsys.com>

Thanks,
Thinh