From mboxrd@z Thu Jan 1 00:00:00 1970 From: Guenter Roeck Subject: Re: [PATCH v2 3/8] watchdog: JZ4740: Register a restart handler Date: Sat, 20 Jan 2018 07:45:46 -0800 Message-ID: <20061de8-fa1f-93eb-eb9b-089c699018aa@roeck-us.net> References: <20171228162939.3928-2-paul@crapouillou.net> <20171230135108.6834-1-paul@crapouillou.net> <20171230135108.6834-3-paul@crapouillou.net> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: Content-Language: en-US Sender: linux-watchdog-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: PrasannaKumar Muralidharan , Paul Cercueil Cc: Ralf Baechle , Rob Herring , Mark Rutland , Wim Van Sebroeck , "open list:OPEN FIRMWARE AND FLATTENED DEVICE TREE BINDINGS" , Linux-MIPS , open list , linux-watchdog-u79uwXL29TY76Z2rM5mHXA@public.gmane.org List-Id: devicetree@vger.kernel.org On 01/19/2018 11:31 PM, PrasannaKumar Muralidharan wrote: > Hi Paul, > > On 30 December 2017 at 19:21, Paul Cercueil wrote: >> The watchdog driver can restart the system by simply configuring the >> hardware for a timeout of 0 seconds. >> >> Signed-off-by: Paul Cercueil >> Reviewed-by: Guenter Roeck >> --- >> drivers/watchdog/jz4740_wdt.c | 9 +++++++++ >> 1 file changed, 9 insertions(+) >> >> v2: No change >> >> diff --git a/drivers/watchdog/jz4740_wdt.c b/drivers/watchdog/jz4740_wdt.c >> index 92d6ca8ceb49..fa7f49a3212c 100644 >> --- a/drivers/watchdog/jz4740_wdt.c >> +++ b/drivers/watchdog/jz4740_wdt.c >> @@ -130,6 +130,14 @@ static int jz4740_wdt_stop(struct watchdog_device *wdt_dev) >> return 0; >> } >> >> +static int jz4740_wdt_restart(struct watchdog_device *wdt_dev, >> + unsigned long action, void *data) >> +{ >> + wdt_dev->timeout = 0; >> + jz4740_wdt_start(wdt_dev); >> + return 0; >> +} >> + >> static const struct watchdog_info jz4740_wdt_info = { >> .options = WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING | WDIOF_MAGICCLOSE, >> .identity = "jz4740 Watchdog", >> @@ -141,6 +149,7 @@ static const struct watchdog_ops jz4740_wdt_ops = { >> .stop = jz4740_wdt_stop, >> .ping = jz4740_wdt_ping, >> .set_timeout = jz4740_wdt_set_timeout, >> + .restart = jz4740_wdt_restart, >> }; >> >> #ifdef CONFIG_OF >> -- >> 2.11.0 >> >> > > Noticed that min_timeout of the watchdog device is set to 1 but this > function calls start with timeout set to 0. Even though this works I > feel it is better to set min_timeout to 0. > No. That would be wrong. If you want to be pedantic, write a new function __jz4740_wdt_set_timeout(u16 clock_div, u16 timeout_value) and call it instead, but don't mess with min_timeout. Guenter -- To unsubscribe from this list: send the line "unsubscribe linux-watchdog" in the body of a message to majordomo-u79uwXL29TY76Z2rM5mHXA@public.gmane.org More majordomo info at http://vger.kernel.org/majordomo-info.html