From: Wolfram Sang <wsa@the-dreams.de>
To: Wolfram Sang <wsa+renesas@sang-engineering.com>
Cc: linux-watchdog@vger.kernel.org,
linux-renesas-soc@vger.kernel.org,
Geert Uytterhoeven <geert@linux-m68k.org>,
Guenter Roeck <linux@roeck-us.net>
Subject: Re: [RFC PATCH] watchdog: renesas_wdt: support handover from bootloader
Date: Fri, 24 May 2019 15:52:37 +0200 [thread overview]
Message-ID: <20190524135237.GC15892@kunai> (raw)
In-Reply-To: <20190415105201.2078-1-wsa+renesas@sang-engineering.com>
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On Mon, Apr 15, 2019 at 12:52:01PM +0200, Wolfram Sang wrote:
> Support an already running watchdog by checking its enable bit and set
> up the status accordingly before registering the device.
>
> Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
After second thought, I am getting confused a little. If the WDT is
already running then
a) before this patch: after successful probe, RPM will disable the
clock until userspace opens the watchdog device
b) after this patch: during probe, our default timeout will be
programmed and because of WDOG_HW_RUNNING, the core will generate pings
until userspace opens the watchdog device.
So, b) will protect from a crashing kernel (no pings anymore) but not
from something like missing rootfs, or?
The usecase I had in mind ("give the kernel <x> seconds to boot into
working userspace") seems to be achieved by loading the WDT driver as a
module then, I guess?
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next prev parent reply other threads:[~2019-05-24 13:52 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-04-15 10:52 [RFC PATCH] watchdog: renesas_wdt: support handover from bootloader Wolfram Sang
2019-04-17 18:05 ` Guenter Roeck
2019-04-17 19:01 ` Wolfram Sang
2019-05-09 7:38 ` Geert Uytterhoeven
2019-05-24 13:52 ` Wolfram Sang [this message]
2019-06-07 20:41 ` Guenter Roeck
2019-06-07 20:55 ` Wolfram Sang
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