From: Guenter Roeck <linux@roeck-us.net>
To: Alan Cox <gnomes@lxorguk.ukuu.org.uk>
Cc: Rasmus Villemoes <rasmus.villemoes@prevas.dk>,
linux-watchdog@vger.kernel.org, linux-doc@vger.kernel.org,
linux-kernel@vger.kernel.org,
Sebastian Reichel <sebastian.reichel@collabora.co.uk>,
esben.haabendal@gmail.com
Subject: Re: [PATCH v5 0/3] watchdog: allow setting deadline for opening /dev/watchdogN
Date: Mon, 22 May 2017 12:44:48 -0700 [thread overview]
Message-ID: <20170522194448.GA29867@roeck-us.net> (raw)
In-Reply-To: <20170522190751.5bf5e813@alans-desktop>
On Mon, May 22, 2017 at 07:07:51PM +0100, Alan Cox wrote:
> On Mon, 22 May 2017 16:06:36 +0200
> Rasmus Villemoes <rasmus.villemoes@prevas.dk> wrote:
>
> > If a watchdog driver tells the framework that the device is running,
> > the framework takes care of feeding the watchdog until userspace opens
> > the device. If the userspace application which is supposed to do that
> > never comes up properly, the watchdog is fed indefinitely by the
> > kernel. This can be especially problematic for embedded devices.
> >
> > These patches allow one to set a maximum time for which the kernel
> > will feed the watchdog, thus ensuring that either userspace has come
> > up, or the board gets reset. This allows fallback logic in the
> > bootloader to attempt some recovery (for example, if an automatic
> > update is in progress, it could roll back to the previous version).
>
>
> This makes sense except for being a CONFIG_ option not a boot parameter.
> If it's a boot parameter then the same kernel works for multiple systems
> and is general. If it's compile time then you have to build a custom
> kernel.
>
> For some embedded stuff that might not matter (although I bet they'd
> prefer it command line/device tree too) but for something like an x86
> platform where you are deploying a standard vendor supplied kernel it's
> bad to do it that way IMHO.
>
> In other words I think you should drop patch 3 but the rest is good.
>
Same here. Can we assume a formal Reviewed-by: from you for the first two
patches ?
Thanks,
Guenter
> Alan
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next prev parent reply other threads:[~2017-05-22 19:44 UTC|newest]
Thread overview: 20+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-05-22 14:06 [PATCH v5 0/3] watchdog: allow setting deadline for opening /dev/watchdogN Rasmus Villemoes
2017-05-22 14:06 ` [PATCH v5 1/3] watchdog: introduce watchdog_worker_should_ping helper Rasmus Villemoes
2017-05-25 0:53 ` Guenter Roeck
2017-05-22 14:06 ` [PATCH v5 2/3] watchdog: introduce watchdog.open_timeout commandline parameter Rasmus Villemoes
2017-05-25 0:56 ` Guenter Roeck
2017-05-30 8:00 ` Rasmus Villemoes
2017-05-22 14:06 ` [PATCH v5 3/3] watchdog: introduce CONFIG_WATCHDOG_OPEN_TIMEOUT Rasmus Villemoes
2017-05-22 18:07 ` [PATCH v5 0/3] watchdog: allow setting deadline for opening /dev/watchdogN Alan Cox
2017-05-22 19:44 ` Guenter Roeck [this message]
2017-05-23 7:15 ` Rasmus Villemoes
2017-05-24 14:19 ` Esben Haabendal
2017-05-30 8:56 ` [PATCH v6 " Rasmus Villemoes
2017-05-30 8:56 ` [PATCH v6 1/3] watchdog: introduce watchdog_worker_should_ping helper Rasmus Villemoes
2017-05-30 8:56 ` [PATCH v6 2/3] watchdog: introduce watchdog.open_timeout commandline parameter Rasmus Villemoes
2017-07-08 15:12 ` [v6, " Guenter Roeck
2017-05-30 8:56 ` [PATCH v6 3/3] watchdog: introduce CONFIG_WATCHDOG_OPEN_TIMEOUT Rasmus Villemoes
2017-07-08 15:15 ` [v6,3/3] " Guenter Roeck
2017-07-11 15:50 ` Wim Van Sebroeck
2017-06-06 8:08 ` [PATCH v6 0/3] watchdog: allow setting deadline for opening /dev/watchdogN Rasmus Villemoes
2017-06-06 13:47 ` Guenter Roeck
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