Re: [PATCH] rtc: rs5c372: add missing error code for unknown RTC type

[Alexandre Belloni <alexandre.belloni@bootlin.com>]

On 27/08/2026 09:58:46+0800, Liu Dalin wrote:
> In rs5c372_probe(), when an unknown RTC type is encountered in the
> switch default case, the local variable 'err' is still 0 from its
> initialization. The subsequent goto to the exit label then returns
> success, even though probe has failed.
> 
> Set err = -ENODEV before jumping to exit to properly report the
> failure to the caller.
> 
> Fixes smatch warnings:
> - drivers/rtc/rtc-rs5c372.c:860 rs5c372_probe() warn: missing error
>   code 'err'
> 
> Fixes: cb26b572dc394 ("[PATCH] Update the rtc-rs5c372 driver")
> Assisted-by: smatch:2.0 [static analysis]
> Signed-off-by: Liu Dalin <liudalin@kylinsec.com.cn>
> ---
>  drivers/rtc/rtc-rs5c372.c | 1 +
>  1 file changed, 1 insertion(+)
> 
> diff --git a/drivers/rtc/rtc-rs5c372.c b/drivers/rtc/rtc-rs5c372.c
> index 24bd795d9d95..84407119caba 100644
> --- a/drivers/rtc/rtc-rs5c372.c
> +++ b/drivers/rtc/rtc-rs5c372.c
> @@ -857,6 +857,7 @@ static int rs5c372_probe(struct i2c_client *client)
>  		break;
>  	default:
>  		dev_err(&client->dev, "unknown RTC type\n");
> +		err = -ENODEV;

But isn't this dead code that will never be reached? In what case would
you be probed and not match any i2c_device_id?

-- 
Alexandre Belloni, co-owner and COO, Bootlin
Embedded Linux and Kernel engineering
https://bootlin.com