Re: [PATCH] usb: typec: ucsi: fix Clang -Wsign-conversion warning

[Heikki Krogerus <heikki.krogerus@linux.intel.com>]

On Tue, Apr 22, 2025 at 02:47:17PM +0100, Qasim Ijaz wrote:
> debugfs.c emits the following warnings when compiling with the -Wsign-conversion flag with clang 15:
> 
> drivers/usb/typec/ucsi/debugfs.c:58:27: warning: implicit conversion changes signedness: 'int' to 'u32' (aka 'unsigned int') [-Wsign-conversion]
>                 ucsi->debugfs->status = ret;
>                                       ~ ^~~
> drivers/usb/typec/ucsi/debugfs.c:71:25: warning: implicit conversion changes signedness: 'u32' (aka 'unsigned int') to 'int' [-Wsign-conversion]
>                 return ucsi->debugfs->status;
>                 ~~~~~~ ~~~~~~~~~~~~~~~^~~~~~
>                 
> During ucsi_cmd() we see:
> 
> 	if (ret < 0) {
> 		ucsi->debugfs->status = ret;
> 		return ret;
> 	}
> 	
> But "status" is u32 meaning unsigned wrap-around occurs when assigning a value which is < 0 to it, this obscures the real status.
> 
> To fix this make the "status" of type int since ret is also of type int.
> 
> Fixes: df0383ffad64 ("usb: typec: ucsi: Add debugfs for ucsi commands")
> Cc: stable@vger.kernel.org
> Signed-off-by: Qasim Ijaz <qasdev00@gmail.com>

Reviewed-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>

> ---
>  drivers/usb/typec/ucsi/ucsi.h | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/drivers/usb/typec/ucsi/ucsi.h b/drivers/usb/typec/ucsi/ucsi.h
> index 3a2c1762bec1..525d28160413 100644
> --- a/drivers/usb/typec/ucsi/ucsi.h
> +++ b/drivers/usb/typec/ucsi/ucsi.h
> @@ -432,7 +432,7 @@ struct ucsi_debugfs_entry {
>  		u64 low;
>  		u64 high;
>  	} response;
> -	u32 status;
> +	int status;
>  	struct dentry *dentry;
>  };
>  
> -- 
> 2.39.5

-- 
heikki