From mboxrd@z Thu Jan 1 00:00:00 1970 From: linux@roeck-us.net (Guenter Roeck) Date: Fri, 02 May 2014 06:22:36 -0700 Subject: [RFC PATCH 1/5] watchdog: Add API to trigger reboots In-Reply-To: <20140502100105.GC17370@arm.com> References: <1398958893-30049-1-git-send-email-linux@roeck-us.net> <1398958893-30049-2-git-send-email-linux@roeck-us.net> <20140502100105.GC17370@arm.com> Message-ID: <53639C1C.8050701@roeck-us.net> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org On 05/02/2014 03:01 AM, Will Deacon wrote: > Hi Guenter, > > This looks pretty sensible to me (and the arm/arm64 bits look fine too), but > I have one question below... > > On Thu, May 01, 2014 at 04:41:29PM +0100, Guenter Roeck wrote: >> Some hardware implements reboot through its watchdog hardware, >> for example by triggering a watchdog timeout. Platform specific >> code starts to spread into watchdog drivers, typically by setting >> pointers to a callback functions which is then called from the >> platform reset handler. >> >> To simplify code and provide a unified API to trigger reboots by >> watchdog drivers, provide a single API to trigger such reboots >> through the watchdog subsystem. >> >> Signed-off-by: Guenter Roeck >> --- >> drivers/watchdog/watchdog_core.c | 17 +++++++++++++++++ >> include/linux/watchdog.h | 11 +++++++++++ >> 2 files changed, 28 insertions(+) >> >> diff --git a/drivers/watchdog/watchdog_core.c b/drivers/watchdog/watchdog_core.c >> index cec9b55..4ec6e2f 100644 >> --- a/drivers/watchdog/watchdog_core.c >> +++ b/drivers/watchdog/watchdog_core.c >> @@ -43,6 +43,17 @@ >> static DEFINE_IDA(watchdog_ida); >> static struct class *watchdog_class; >> >> +static struct watchdog_device *wdd_reboot_dev; >> + >> +void watchdog_do_reboot(enum reboot_mode mode, const char *cmd) >> +{ >> + if (wdd_reboot_dev) { >> + if (wdd_reboot_dev->ops->reboot) >> + wdd_reboot_dev->ops->reboot(wdd_reboot_dev, mode, cmd); >> + } >> +} > > What reboot_mode values would you expect a watchdog to support other than > REBOOT_HARD? Also, is the cmd even useful here? > Answer is "I don't know" in both cases. I thought about dropping the parameters, but then I thought it does not hurt to have them around either. I am open to suggestions and to dropping the parameters if everyone agrees that they are useless. Guenter