Re: [PATCH] serial: atmel: Check return value of platform_get_irq() in atmel_init_port()

[Greg KH <gregkh@linuxfoundation.org>]

On Wed, Oct 18, 2023 at 09:15:21AM +0000, Yi Yang wrote:
> The platform_get_irq() might be failed and return a negative result, there
> should be return an error code when platform_get_irq() failed.
> Fix it by add check return value of platform_get_irq().
> 
> Fixes: 5bb221b0ad65 ("serial: atmel: Use platform_get_irq() to get the interrupt")
> Signed-off-by: Yi Yang <yiyang13@huawei.com>
> ---
>  drivers/tty/serial/atmel_serial.c | 6 +++++-
>  1 file changed, 5 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/tty/serial/atmel_serial.c b/drivers/tty/serial/atmel_serial.c
> index 1946fafc3f3e..4984bec88445 100644
> --- a/drivers/tty/serial/atmel_serial.c
> +++ b/drivers/tty/serial/atmel_serial.c
> @@ -2540,13 +2540,17 @@ static int atmel_init_port(struct atmel_uart_port *atmel_port,
>  	atmel_init_property(atmel_port, pdev);
>  	atmel_set_ops(port);
>  
> +	ret = platform_get_irq(mpdev, 0);
> +	if (ret < 0)
> +		return 0;
> +
>  	port->iotype		= UPIO_MEM;
>  	port->flags		= UPF_BOOT_AUTOCONF | UPF_IOREMAP;
>  	port->ops		= &atmel_pops;
>  	port->fifosize		= 1;
>  	port->dev		= &pdev->dev;
>  	port->mapbase		= mpdev->resource[0].start;
> -	port->irq		= platform_get_irq(mpdev, 0);
> +	port->irq		= ret;

Sorry, no, this makes things much more complex and error-prone in the
long term, for a function that in reality, never fails (obviously
otherwise this would have been reported.)

How did you test this?

thanks,

greg k-h