[systemd-devel] [PATCH] watchdog: Don't require WDIOC_SETOPTIONS/WDIOS_ENABLECARD

[Lennart Poettering]

On Mon, 15.06.15 18:14, Jean Delvare (jdelvare at suse.de) wrote:

> Not all watchdog drivers implement WDIOC_SETOPTIONS. Drivers which do
> not implement it have their device always enabled. So it's fine to
> report an error if WDIOS_DISABLECARD is passed and the ioctl is not
> implemented, however failing when WDIOS_ENABLECARD is passed and the
> ioctl is not implemented is not good: if the device was already
> enabled then WDIOS_ENABLECARD was a no-op and wasn't needed in the
> first place. So we can just ignore the error and continue.

Isn't this something that should be fixed in the drivers?

> ---
>  src/shared/watchdog.c |    3 ++-
>  1 file changed, 2 insertions(+), 1 deletion(-)
> 
> --- a/src/shared/watchdog.c
> +++ b/src/shared/watchdog.c
> @@ -64,7 +64,8 @@ static int update_timeout(void) {
>  
>                  flags = WDIOS_ENABLECARD;
>                  r = ioctl(watchdog_fd, WDIOC_SETOPTIONS, &flags);
> -                if (r < 0) {
> +                /* ENOTTY means the watchdog is always enabled so we're fine */
> +                if (r < 0 && errno != ENOTTY) {
>                          log_warning("Failed to enable hardware watchdog: %m");
>                          return -errno;

If this is something to fix in systemd, rather than fix in the
drivers:  am pretty sure that we should log in all cases, but change
the log level to LOG_DEBUG if its ENOTTY. i.e. use "log_full(errno ==
ENOTTY ? LOG_DEBUG : LOG_WARNING"...

Lennart

-- 
Lennart Poettering, Red Hat