Date:   Mon, 20 Dec 2021 11:44:21 +0100
From:   Greg KH <gregkh@linuxfoundation.org>
To:     Jiasheng Jiang <jiasheng@iscas.ac.cn>
Cc:     agross@kernel.org, bjorn.andersson@linaro.org, balbi@kernel.org,
        p.zabel@pengutronix.de, linux-arm-msm@vger.kernel.org,
        linux-usb@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH] usb: dwc3: qcom: Check for null irq pointer
Message-ID: <YcBehfPqhHpd/FSK@kroah.com>
References: <20211220101520.930658-1-jiasheng@iscas.ac.cn>
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In-Reply-To: <20211220101520.930658-1-jiasheng@iscas.ac.cn>
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On Mon, Dec 20, 2021 at 06:15:20PM +0800, Jiasheng Jiang wrote:
> The return value of platform_get_irq() needs to be checked.
> To avoid use of null pointer in case that there is no irq.
> 
> Fixes: 2bc02355f8ba ("usb: dwc3: qcom: Add support for booting with ACPI")
> Signed-off-by: Jiasheng Jiang <jiasheng@iscas.ac.cn>
> ---
>  drivers/usb/dwc3/dwc3-qcom.c | 5 +++++
>  1 file changed, 5 insertions(+)
> 
> diff --git a/drivers/usb/dwc3/dwc3-qcom.c b/drivers/usb/dwc3/dwc3-qcom.c
> index 49e6ca94486d..f04fb3f2fb85 100644
> --- a/drivers/usb/dwc3/dwc3-qcom.c
> +++ b/drivers/usb/dwc3/dwc3-qcom.c
> @@ -614,6 +614,11 @@ static int dwc3_qcom_acpi_register_core(struct platform_device *pdev)
>  		qcom->acpi_pdata->dwc3_core_base_size;
>  
>  	irq = platform_get_irq(pdev_irq, 0);
> +	if (!irq) {
> +		ret = -EINVAL;

That is NOT the proper way to check the return value of this function
call.