Re: [PATCH] watchdog: alim7101: Mark expected switch fall-through

From: Guenter Roeck
Date: Wed Mar 20 2019 - 20:12:18 EST


On 3/20/19 11:16 AM, Gustavo A. R. Silva wrote:
In preparation to enabling -Wimplicit-fallthrough, mark switch
cases where we are expecting to fall through.

This patch fixes the following warning:

drivers/watchdog/alim7101_wdt.c: In function âfop_ioctlâ:
drivers/watchdog/alim7101_wdt.c:279:3: warning: this statement may fall through [-Wimplicit-fallthrough=]
wdt_keepalive();
^~~~~~~~~~~~~~~
drivers/watchdog/alim7101_wdt.c:282:2: note: here
case WDIOC_GETTIMEOUT:
^~~~

Notice that, in this particular case, the /* Fall through */
comment is placed at the very bottom of the case statement,
which is what GCC is expecting to find.

Warning level 3 was used: -Wimplicit-fallthrough=3

This patch is part of the ongoing efforts to enabling
-Wimplicit-fallthrough.

Signed-off-by: Gustavo A. R. Silva <gustavo@xxxxxxxxxxxxxx>

Reviewed-by: Guenter Roeck <linux@xxxxxxxxxxxx>

---
drivers/watchdog/alim7101_wdt.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/watchdog/alim7101_wdt.c b/drivers/watchdog/alim7101_wdt.c
index 12f7ea62dddd..f5ada07e9202 100644
--- a/drivers/watchdog/alim7101_wdt.c
+++ b/drivers/watchdog/alim7101_wdt.c
@@ -277,8 +277,8 @@ static long fop_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
return -EINVAL;
timeout = new_timeout;
wdt_keepalive();
- /* Fall through */
}
+ /* Fall through */
case WDIOC_GETTIMEOUT:
return put_user(timeout, p);
default: