On Thu, Feb 06, 2014 at 06:02:56PM -0800, Guenter Roeck wrote: > On 02/06/2014 09:20 AM, Ezequiel Garcia wrote: > > Having the watchdog initially fully stopped is important to avoid > > any spurious watchdog triggers, in case the registers are not in > > its reset state. > > > > Reviewed-by: Guenter Roeck <linux@xxxxxxxxxxxx> > > Tested-by: Sebastian Hesselbarth <sebastian.hesselbarth@xxxxxxxxx> > > Tested-by: Willy Tarreau <w@xxxxxx> > > Signed-off-by: Ezequiel Garcia <ezequiel.garcia@xxxxxxxxxxxxxxxxxx> > > --- > > drivers/watchdog/orion_wdt.c | 3 +++ > > 1 file changed, 3 insertions(+) > > > > diff --git a/drivers/watchdog/orion_wdt.c b/drivers/watchdog/orion_wdt.c > > index 6746033..2dbeee9 100644 > > --- a/drivers/watchdog/orion_wdt.c > > +++ b/drivers/watchdog/orion_wdt.c > > @@ -142,6 +142,9 @@ static int orion_wdt_probe(struct platform_device *pdev) > > orion_wdt.max_timeout = wdt_max_duration; > > watchdog_init_timeout(&orion_wdt, heartbeat, &pdev->dev); > > > > + /* Let's make sure the watchdog is fully stopped */ > > + orion_wdt_stop(&orion_wdt); > > + > > Actually we just had that in another driver, and I stumbled over it there. > > Problem with stopping the watchdog in probe unconditionally is that you can > use it to defeat nowayout: unload the module, then load it again, > and the watchdog is stopped even if nowayout is true. > Hm... I see. > Is this really what you want ? Or, in other words, what is the problem > you are trying to solve ? > Well, this is related to the discussion about the bootloader not reseting the watchdog properly, provoking spurious watchdog triggering. Jason Gunthorpe explained [1] that we needed a particular sequence: 1. Disable WDT 2. Clear bridge 3. Enable WDT We added the irq handling to satisfy (2), and the watchdog stop for (1). The watchdog stop was agreed specifically [2]. Ideas? [1] http://www.spinics.net/lists/arm-kernel/msg302340.html [2] http://www.spinics.net/lists/arm-kernel/msg302507.html -- Ezequiel García, Free Electrons Embedded Linux, Kernel and Android Engineering http://free-electrons.com -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
