watchdog: da9062: do not ping the hw during stop()

[ Upstream commit e9a0e65eda3f78d0b04ec6136c591c000cbc3b76 ]

The da9062 hw has a minimum ping cool down phase of at least 200ms. The
driver takes that into account by setting the min_hw_heartbeat_ms to
300ms and the core guarantees that the hw limit is observed for the
ping() calls. But the core can't guarantee the required minimum ping
cool down phase if a stop() command is send immediately after the ping()
command. So it is not allowed to ping the watchdog within the stop()
command as the driver does. Remove the ping can be done without doubts
because the watchdog gets disabled anyway and a (re)start resets the
watchdog counter too.

Signed-off-by: Marco Felsch <m.felsch@pengutronix.de>
Reviewed-by: Guenter Roeck <linux@roeck-us.net>
Link: https://lore.kernel.org/r/20200120091729.16256-1-m.felsch@pengutronix.de
[groeck: Updated description]
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Wim Van Sebroeck <wim@linux-watchdog.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>

diff --git a/drivers/watchdog/da9062_wdt.c b/drivers/watchdog/da9062_wdt.c
index 9083d3d922b0b4304a3623b307c3b6a66e99f2ef..79383ff620199c20db7d97f61366a24d499d3760 100644 (file)
--- a/drivers/watchdog/da9062_wdt.c
+++ b/drivers/watchdog/da9062_wdt.c
@@ -126,13 +126,6 @@ static int da9062_wdt_stop(struct watchdog_device *wdd)
        struct da9062_watchdog *wdt = watchdog_get_drvdata(wdd);
        int ret;
 
-       ret = da9062_reset_watchdog_timer(wdt);
-       if (ret) {
-               dev_err(wdt->hw->dev, "Failed to ping the watchdog (err = %d)\n",
-                       ret);
-               return ret;
-       }
-
        ret = regmap_update_bits(wdt->hw->regmap,
                                 DA9062AA_CONTROL_D,
                                 DA9062AA_TWDSCALE_MASK,