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Subject: Re: [PATCH] usb: phy: tegra: Use IS_ERR() to check and simplify code
To:     Tang Bin <tangbin@cmss.chinamobile.com>, balbi@kernel.org,
        gregkh@linuxfoundation.org, thierry.reding@gmail.com,
        jonathanh@nvidia.com
Cc:     linux-usb@vger.kernel.org, linux-tegra@vger.kernel.org,
        linux-kernel@vger.kernel.org,
        Zhang Shengju <zhangshengju@cmss.chinamobile.com>
References: <20200910115607.11392-1-tangbin@cmss.chinamobile.com>
From:   Sergei Shtylyov <sergei.shtylyov@gmail.com>
Organization: Brain-dead Software
Message-ID: <d0bd4d4c-0447-6c5f-6dc3-17e5ceae2623@gmail.com>
Date:   Fri, 11 Sep 2020 11:29:59 +0300
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Hello!

On 10.09.2020 14:56, Tang Bin wrote:

> Use IS_ERR() and PTR_ERR() instead of PTR_ERR_OR_ZERO() to
> simplify code, avoid redundant judgements.
> 
> Signed-off-by: Zhang Shengju <zhangshengju@cmss.chinamobile.com>
> Signed-off-by: Tang Bin <tangbin@cmss.chinamobile.com>
> ---
>   drivers/usb/phy/phy-tegra-usb.c | 25 ++++++++++---------------
>   1 file changed, 10 insertions(+), 15 deletions(-)
> 
> diff --git a/drivers/usb/phy/phy-tegra-usb.c b/drivers/usb/phy/phy-tegra-usb.c
> index 6153cc35a..3b901429d 100644
> --- a/drivers/usb/phy/phy-tegra-usb.c
> +++ b/drivers/usb/phy/phy-tegra-usb.c
> @@ -1121,10 +1121,9 @@ static int tegra_usb_phy_probe(struct platform_device *pdev)
>   		return PTR_ERR(tegra_phy->vbus);
>   
>   	tegra_phy->pll_u = devm_clk_get(&pdev->dev, "pll_u");
> -	err = PTR_ERR_OR_ZERO(tegra_phy->pll_u);
> -	if (err) {
> +	if (IS_ERR(tegra_phy->pll_u)) {
>   		dev_err(&pdev->dev, "Failed to get pll_u clock: %d\n", err);

    'err' should be changed here too...

> -		return err;
> +		return PTR_ERR(tegra_phy->pll_u);
>   	}
>   
>   	phy_type = of_usb_get_phy_mode(np);
> @@ -1135,20 +1134,18 @@ static int tegra_usb_phy_probe(struct platform_device *pdev)
>   			return err;
>   
>   		tegra_phy->pad_clk = devm_clk_get(&pdev->dev, "utmi-pads");
> -		err = PTR_ERR_OR_ZERO(tegra_phy->pad_clk);
> -		if (err) {
> +		if (IS_ERR(tegra_phy->pad_clk)) {
>   			dev_err(&pdev->dev,
>   				"Failed to get UTMIP pad clock: %d\n", err);

    Same here.

> -			return err;
> +			return PTR_ERR(tegra_phy->pad_clk);
>   		}
>   
>   		reset = devm_reset_control_get_optional_shared(&pdev->dev,
>   							       "utmi-pads");
> -		err = PTR_ERR_OR_ZERO(reset);
> -		if (err) {
> +		if (IS_ERR(reset)) {
>   			dev_err(&pdev->dev,
>   				"Failed to get UTMI-pads reset: %d\n", err);

    And here.

> -			return err;
> +			return PTR_ERR(reset);
>   		}
>   		tegra_phy->pad_rst = reset;
>   		break;
> @@ -1157,22 +1154,20 @@ static int tegra_usb_phy_probe(struct platform_device *pdev)
>   		tegra_phy->is_ulpi_phy = true;
>   
>   		tegra_phy->clk = devm_clk_get(&pdev->dev, "ulpi-link");
> -		err = PTR_ERR_OR_ZERO(tegra_phy->clk);
> -		if (err) {
> +		if (IS_ERR(tegra_phy->clk)) {
>   			dev_err(&pdev->dev,
>   				"Failed to get ULPI clock: %d\n", err);

    And here.

> -			return err;
> +			return PTR_ERR(tegra_phy->clk);
>   		}
>   
>   		gpiod = devm_gpiod_get_from_of_node(&pdev->dev, np,
>   						    "nvidia,phy-reset-gpio",
>   						    0, GPIOD_OUT_HIGH,
>   						    "ulpi_phy_reset_b");
> -		err = PTR_ERR_OR_ZERO(gpiod);
> -		if (err) {
> +		if (IS_ERR(gpiod)) {
>   			dev_err(&pdev->dev,
>   				"Request failed for reset GPIO: %d\n", err);

    And here.

> -			return err;
> +			return PTR_ERR(gpiod);
>   		}
>   		tegra_phy->reset_gpio = gpiod;
>   

    Overall, this patch is broken and not even worth redoing -- the current 
code seems good...

MBR, Sergei