linux-kernel - Re: [PATCH 01/11] usb: dwc3: st: use scoped device node handling to simplify error paths

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <1ed80a6d-3453-43bc-a008-b4ad21d6d639@foss.st.com>
Date: Wed, 14 Aug 2024 17:43:53 +0200
From: Patrice CHOTARD <patrice.chotard@...s.st.com>
To: Krzysztof Kozlowski <krzysztof.kozlowski@...aro.org>,
        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>
CC: <linux-arm-kernel@...ts.infradead.org>, <linux-usb@...r.kernel.org>,
        <linux-kernel@...r.kernel.org>, <imx@...ts.linux.dev>,
        <linux-arm-msm@...r.kernel.org>
Subject: Re: [PATCH 01/11] usb: dwc3: st: use scoped device node handling to
 simplify error paths



On 8/14/24 12:35, Krzysztof Kozlowski wrote:
> Obtain the device node reference with scoped/cleanup.h to reduce error
> handling and make the code a bit simpler.  Scoped/cleanup.h coding style
> expects variable declaration with initialization, so the
> of_get_compatible_child() call has to be moved earlier, before any goto
> jumps happen.
> 
> Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@...aro.org>
> 
> ---
> 
> This depends on my earlier fix:
> https://lore.kernel.org/all/20240814093957.37940-2-krzysztof.kozlowski@linaro.org/
> ---
>  drivers/usb/dwc3/dwc3-st.c | 25 +++++++++++--------------
>  1 file changed, 11 insertions(+), 14 deletions(-)
> 
> diff --git a/drivers/usb/dwc3/dwc3-st.c b/drivers/usb/dwc3/dwc3-st.c
> index c8c7cd0c1796..98f43d7082d7 100644
> --- a/drivers/usb/dwc3/dwc3-st.c
> +++ b/drivers/usb/dwc3/dwc3-st.c
> @@ -14,6 +14,7 @@
>   * Inspired by dwc3-omap.c and dwc3-exynos.c.
>   */
>  
> +#include <linux/cleanup.h>
>  #include <linux/delay.h>
>  #include <linux/interrupt.h>
>  #include <linux/io.h>
> @@ -197,7 +198,7 @@ static int st_dwc3_probe(struct platform_device *pdev)
>  	struct st_dwc3 *dwc3_data;
>  	struct resource *res;
>  	struct device *dev = &pdev->dev;
> -	struct device_node *node = dev->of_node, *child;
> +	struct device_node *node = dev->of_node;
>  	struct platform_device *child_pdev;
>  	struct regmap *regmap;
>  	int ret;
> @@ -227,6 +228,13 @@ static int st_dwc3_probe(struct platform_device *pdev)
>  	dev_vdbg(&pdev->dev, "glue-logic addr 0x%pK, syscfg-reg offset 0x%x\n",
>  		 dwc3_data->glue_base, dwc3_data->syscfg_reg_off);
>  
> +	struct device_node *child __free(device_node) = of_get_compatible_child(node,
> +										"snps,dwc3");
> +	if (!child) {
> +		dev_err(&pdev->dev, "failed to find dwc3 core node\n");
> +		return -ENODEV;
> +	}
> +
>  	dwc3_data->rstc_pwrdn =
>  		devm_reset_control_get_exclusive(dev, "powerdown");
>  	if (IS_ERR(dwc3_data->rstc_pwrdn)) {
> @@ -248,18 +256,11 @@ static int st_dwc3_probe(struct platform_device *pdev)
>  	/* Manage SoftReset */
>  	reset_control_deassert(dwc3_data->rstc_rst);
>  
> -	child = of_get_compatible_child(node, "snps,dwc3");
> -	if (!child) {
> -		dev_err(&pdev->dev, "failed to find dwc3 core node\n");
> -		ret = -ENODEV;
> -		goto err_node_put;
> -	}
> -
>  	/* Allocate and initialize the core */
>  	ret = of_platform_populate(node, NULL, NULL, dev);
>  	if (ret) {
>  		dev_err(dev, "failed to add dwc3 core\n");
> -		goto err_node_put;
> +		goto undo_softreset;
>  	}
>  
>  	child_pdev = of_find_device_by_node(child);
> @@ -270,7 +271,6 @@ static int st_dwc3_probe(struct platform_device *pdev)
>  	}
>  
>  	dwc3_data->dr_mode = usb_get_dr_mode(&child_pdev->dev);
> -	of_node_put(child);
>  	platform_device_put(child_pdev);
>  
>  	/*
> @@ -282,8 +282,7 @@ static int st_dwc3_probe(struct platform_device *pdev)
>  	ret = st_dwc3_drd_init(dwc3_data);
>  	if (ret) {
>  		dev_err(dev, "drd initialisation failed\n");
> -		of_platform_depopulate(dev);
> -		goto undo_softreset;
> +		goto depopulate;
>  	}
>  
>  	/* ST glue logic init */
> @@ -294,8 +293,6 @@ static int st_dwc3_probe(struct platform_device *pdev)
>  
>  depopulate:
>  	of_platform_depopulate(dev);
> -err_node_put:
> -	of_node_put(child);
>  undo_softreset:
>  	reset_control_assert(dwc3_data->rstc_rst);
>  undo_powerdown:
> 


Reviewed-by: Patrice Chotard <patrice.chotard@...s.st.com>

Thanks
Patrice