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From: Guenter Roeck <linux@roeck-us.net>
To: Stefan Christ <s.christ@phytec.de>,
	linux-watchdog@vger.kernel.org, linux-i2c@vger.kernel.org
Subject: Re: [RFC 1/6] watchdog: da9063_wdt: don't trigger watchdog too fast
Date: Tue, 5 Jul 2016 08:33:35 -0700	[thread overview]
Message-ID: <577BD34F.7000804@roeck-us.net> (raw)
In-Reply-To: <1467724943-13416-2-git-send-email-s.christ@phytec.de>

On 07/05/2016 06:22 AM, Stefan Christ wrote:
> Triggering the watchdog faster than T_WDMIN=256ms leads to resets of the
> da9063 chip. The datasheet says that the watchdog must only be triggered
> in the timeframe T_WDMIN to T_WDMAX. The T_WDMAX is configured in the
> driver.
>
> This problem was already mentioned in the patch:
>
>      http://comments.gmane.org/gmane.linux.watchdog/1708
>
> You also could say that this behavior is a feature. When the userspace
> goes wild, triggering the watchdog to fast, the system is reseted. But
> there is currently no information in the watchdog ABI to report a
> minimum wait time between two watchdog heartbeats.
>

There isn't ? What is the problem with min_hw_heartbeat_ms which was
introduced exactly for that purpose ?

Thanks,
Guenter

  reply	other threads:[~2016-07-05 15:33 UTC|newest]

Thread overview: 21+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2016-07-05 13:22 [PATCH 0/6] Implement I2C restart handler Stefan Christ
2016-07-05 13:22 ` Stefan Christ
2016-07-05 13:22 ` [RFC 1/6] watchdog: da9063_wdt: don't trigger watchdog too fast Stefan Christ
2016-07-05 15:33   ` Guenter Roeck [this message]
     [not found]     ` <577BD34F.7000804-0h96xk9xTtrk1uMJSBkQmQ@public.gmane.org>
2016-07-06  8:42       ` Stefan Christ
2016-07-06  8:42         ` Stefan Christ
2016-07-05 13:22 ` [RFC 2/6] watchdog: da9063_wdt: use delayed work to trigger Stefan Christ
2016-07-05 13:22 ` [RFC 3/6] i2c-imx: add blocking xfer function Stefan Christ
     [not found] ` <1467724943-13416-1-git-send-email-s.christ-guT5V/WYfQezQB+pC5nmwQ@public.gmane.org>
2016-07-05 13:22   ` [RFC 4/6] i2c-core: add possibility to block an adapter for a single user Stefan Christ
2016-07-05 13:22     ` Stefan Christ
2016-07-05 13:22   ` [RFC 6/6] watchdog: da9063_wdt: add schedule-free and race-free restart handler Stefan Christ
2016-07-05 13:22     ` Stefan Christ
2016-07-05 15:37     ` Guenter Roeck
2016-07-05 13:22 ` [RFC 5/6] mfd: da9063: save i2c_client for later use Stefan Christ
2016-07-05 14:58 ` [PATCH 0/6] Implement I2C restart handler Wolfram Sang
2016-07-05 15:41   ` Guenter Roeck
2016-07-05 15:41     ` Guenter Roeck
2016-07-06  9:18   ` Stefan Christ
2016-07-06  9:18     ` Stefan Christ
2016-07-06 14:16     ` Wolfram Sang
2016-07-06 14:16       ` Wolfram Sang

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