Re: [PATCH 072/141] can: peak_usb: Fix fall-through warnings for Clang - Marc Kleine-Budde

From: Marc Kleine-Budde <mkl@pengutronix.de>
To: "Gustavo A. R. Silva" <gustavoars@kernel.org>,
	Wolfgang Grandegger <wg@grandegger.com>,
	"David S. Miller" <davem@davemloft.net>,
	Jakub Kicinski <kuba@kernel.org>
Cc: linux-can@vger.kernel.org, netdev@vger.kernel.org,
	linux-kernel@vger.kernel.org, linux-hardening@vger.kernel.org
Subject: Re: [PATCH 072/141] can: peak_usb: Fix fall-through warnings for Clang
Date: Sat, 21 Nov 2020 14:17:45 +0100	[thread overview]
Message-ID: <bf3dbc5c-c34e-b3ef-abb6-0c88d8a90332@pengutronix.de> (raw)
In-Reply-To: <aab7cf16bf43cc7c3e9c9930d2dae850c1d07a3c.1605896059.git.gustavoars@kernel.org>


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On 11/20/20 7:34 PM, Gustavo A. R. Silva wrote:
> In preparation to enable -Wimplicit-fallthrough for Clang, fix a warning
> by explicitly adding a break statement instead of letting the code fall
> through to the next case.
> 
> Link: https://github.com/KSPP/linux/issues/115
> Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>
> ---
>  drivers/net/can/usb/peak_usb/pcan_usb_core.c | 2 ++
>  1 file changed, 2 insertions(+)
> 
> diff --git a/drivers/net/can/usb/peak_usb/pcan_usb_core.c b/drivers/net/can/usb/peak_usb/pcan_usb_core.c
> index c2764799f9ef..fd65a155be3b 100644
> --- a/drivers/net/can/usb/peak_usb/pcan_usb_core.c
> +++ b/drivers/net/can/usb/peak_usb/pcan_usb_core.c
> @@ -299,6 +299,8 @@ static void peak_usb_write_bulk_callback(struct urb *urb)
>  		if (net_ratelimit())
>  			netdev_err(netdev, "Tx urb aborted (%d)\n",
>  				   urb->status);
> +		break;
> +
>  	case -EPROTO:
>  	case -ENOENT:
>  	case -ECONNRESET:
> 

What about moving the default to the end if the case, which is more common anyways:

diff --git a/drivers/net/can/usb/peak_usb/pcan_usb_core.c b/drivers/net/can/usb/peak_usb/pcan_usb_core.c
index 204ccb27d6d9..e8977dd10902 100644
--- a/drivers/net/can/usb/peak_usb/pcan_usb_core.c
+++ b/drivers/net/can/usb/peak_usb/pcan_usb_core.c
@@ -295,16 +295,16 @@ static void peak_usb_write_bulk_callback(struct urb *urb)
                netif_trans_update(netdev);
                break;
 
-       default:
-               if (net_ratelimit())
-                       netdev_err(netdev, "Tx urb aborted (%d)\n",
-                                  urb->status);
        case -EPROTO:
        case -ENOENT:
        case -ECONNRESET:
        case -ESHUTDOWN:
-
                break;
+
+       default:
+               if (net_ratelimit())
+                       netdev_err(netdev, "Tx urb aborted (%d)\n",
+                                  urb->status);
        }
 
        /* should always release echo skb and corresponding context */


Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

Marc

-- 
Pengutronix e.K.                 | Marc Kleine-Budde           |
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