Messages in this thread | | | Date | Tue, 26 Sep 2017 08:13:09 -0700 | From | Guenter Roeck <> | Subject | Re: [PATCH v4 1/2] watchdog: dw_wdt: add stop watchdog operation |
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On Tue, Sep 26, 2017 at 08:11:22AM +0200, Oleksij Rempel wrote: > The only way of stopping the watchdog is by resetting it. > Add the watchdog op for stopping the device and reset if > a reset line is provided. > > At same time WDOG_HW_RUNNING should be remove from dw_wdt_start. > As commented by Guenter Roeck: > dw_wdt sets WDOG_HW_RUNNING in its open function. Result is > that the kref_get() in watchdog_open() won't be executed. But then > kref_put() in close will be called since the watchdog now does stop. > This causes the imbalance. > > Signed-off-by: Oleksij Rempel <o.rempel@pengutronix.de> > Cc: Wim Van Sebroeck <wim@iguana.be> > Cc: Guenter Roeck <linux@roeck-us.net> > Cc: linux-watchdog@vger.kernel.org
Reviewed-by: Guenter Roeck <linux@roeck-us.net>
> --- > > changes v4: > - remove WDOG_HW_RUNNING from dw_wdt_start. > > changes v3: > - don't return error if rst is not present and set WDOG_HW_RUNNING bit > to notify watchdog core. > > changes v2: > - test if dw_wdt->rst is NULL instead of IS_ERR > > drivers/watchdog/dw_wdt.c | 18 ++++++++++++++++-- > 1 file changed, 16 insertions(+), 2 deletions(-) > > diff --git a/drivers/watchdog/dw_wdt.c b/drivers/watchdog/dw_wdt.c > index 36be987ff9ef..c2f4ff516230 100644 > --- a/drivers/watchdog/dw_wdt.c > +++ b/drivers/watchdog/dw_wdt.c > @@ -127,14 +127,27 @@ static int dw_wdt_start(struct watchdog_device *wdd) > > dw_wdt_set_timeout(wdd, wdd->timeout); > > - set_bit(WDOG_HW_RUNNING, &wdd->status); > - > writel(WDOG_CONTROL_REG_WDT_EN_MASK, > dw_wdt->regs + WDOG_CONTROL_REG_OFFSET); > > return 0; > } > > +static int dw_wdt_stop(struct watchdog_device *wdd) > +{ > + struct dw_wdt *dw_wdt = to_dw_wdt(wdd); > + > + if (!dw_wdt->rst) { > + set_bit(WDOG_HW_RUNNING, &wdd->status); > + return 0; > + } > + > + reset_control_assert(dw_wdt->rst); > + reset_control_deassert(dw_wdt->rst); > + > + return 0; > +} > + > static int dw_wdt_restart(struct watchdog_device *wdd, > unsigned long action, void *data) > { > @@ -173,6 +186,7 @@ static const struct watchdog_info dw_wdt_ident = { > static const struct watchdog_ops dw_wdt_ops = { > .owner = THIS_MODULE, > .start = dw_wdt_start, > + .stop = dw_wdt_stop, > .ping = dw_wdt_ping, > .set_timeout = dw_wdt_set_timeout, > .get_timeleft = dw_wdt_get_timeleft, > -- > 2.11.0 >
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