Subject: Re: [PATCH] serial: mps2-uart: Check for error irq
To:     Jiasheng Jiang <jiasheng@iscas.ac.cn>, gregkh@linuxfoundation.org,
        jirislaby@kernel.org, liviu.dudau@arm.com, sudeep.holla@arm.com,
        lorenzo.pieralisi@arm.com
Cc:     linux-serial@vger.kernel.org, linux-arm-kernel@lists.infradead.org,
        linux-kernel@vger.kernel.org
References: <20211222033604.1049339-1-jiasheng@iscas.ac.cn>
From:   Vladimir Murzin <vladimir.murzin@arm.com>
Message-ID: <7147a531-2537-81e6-6c4b-2c3c98c6ec59@arm.com>
Date:   Wed, 22 Dec 2021 10:23:19 +0000
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On 12/22/21 3:36 AM, Jiasheng Jiang wrote:
> I find that platform_get_irq() will not always succeed.
> It will return error irq in case there is no suitable irq.
> Therefore, it might be better to check it if order to avoid the use of
> error irq.
> 
> Fixes: 041f031def33 ("serial: mps2-uart: add MPS2 UART driver")
> Signed-off-by: Jiasheng Jiang <jiasheng@iscas.ac.cn>
> ---
>  drivers/tty/serial/mps2-uart.c | 10 ++++++++++
>  1 file changed, 10 insertions(+)
> 
> diff --git a/drivers/tty/serial/mps2-uart.c b/drivers/tty/serial/mps2-uart.c
> index 587b42f754cb..117d9896051f 100644
> --- a/drivers/tty/serial/mps2-uart.c
> +++ b/drivers/tty/serial/mps2-uart.c
> @@ -585,10 +585,20 @@ static int mps2_init_port(struct platform_device *pdev,
>  
>  	if (mps_port->flags & UART_PORT_COMBINED_IRQ) {
>  		mps_port->port.irq = platform_get_irq(pdev, 0);
> +		if (mps_port->port.irq < 0)
> +			return mps_port->port.irq;
>  	} else {
>  		mps_port->rx_irq = platform_get_irq(pdev, 0);
> +		if (mps_port->rx_irq < 0)
> +			return mps_port->rx_irq;
> +
>  		mps_port->tx_irq = platform_get_irq(pdev, 1);
> +		if (mps_port->tx_irq < 0)
> +			return mps_port->tx_irq;
> +
>  		mps_port->port.irq = platform_get_irq(pdev, 2);
> +		if (mps_port->port.irq < 0)
> +			return mps_port->port.irq;
>  	}
>  
>  	return ret;
> 

Acked-by: Vladimir Murzin <vladimir.murzin@arm.com>