watchdog: only run driver set_pretimeout op if device supports it

Some watchdog devices might conditionally support pretimeouts (e.g. if
an interrupt is exposed for the device) but some watchdog drivers might
still define the set_pretimeout operation (e.g. the mtk_wdt driver) and
indicate support at runtime through the WDIOF_PRETIMEOUT flag. If the
kernel is compiled with CONFIG_WATCHDOG_HRTIMER_PRETIMEOUT enabled,
watchdog_set_pretimeout would run the driver specific set_pretimeout
even if WDIOF_PRETIMEOUT is not set which might have unintended
consequences.

So this change checks that the device flags and only runs the driver
operation if pretimeouts are supported.

Signed-off-by: Curtis Klein <[email protected]>
Reviewed-by: Guenter Roeck <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Guenter Roeck <[email protected]>
Signed-off-by: Wim Van Sebroeck <[email protected]>

diff --git a/drivers/watchdog/watchdog_dev.c b/drivers/watchdog/watchdog_dev.c
index 3bab324852732ef564cfd768cc1b8233599c0a6f..5bf795c1b346b5e35f5b75fee2d94c287bd20118 100644 (file)
--- a/drivers/watchdog/watchdog_dev.c
+++ b/drivers/watchdog/watchdog_dev.c
@@ -401,7 +401,7 @@ static int watchdog_set_pretimeout(struct watchdog_device *wdd,
        if (watchdog_pretimeout_invalid(wdd, timeout))
                return -EINVAL;
 
-       if (wdd->ops->set_pretimeout)
+       if (wdd->ops->set_pretimeout && (wdd->info->options & WDIOF_PRETIMEOUT))
                err = wdd->ops->set_pretimeout(wdd, timeout);
        else
                wdd->pretimeout = timeout;