* [PATCH master 2/2] Documentation: user: watchdog: sync with current state
2021-04-26 11:34 [PATCH master 1/2] sandbox: watchdog: don't return positive values from set_timeout Ahmad Fatoum
@ 2021-04-26 11:34 ` Ahmad Fatoum
2021-05-03 10:38 ` [PATCH master 1/2] sandbox: watchdog: don't return positive values from set_timeout Sascha Hauer
1 sibling, 0 replies; 3+ messages in thread
From: Ahmad Fatoum @ 2021-04-26 11:34 UTC (permalink / raw)
To: barebox; +Cc: Ahmad Fatoum, has
Since most of the documentation was written, the watchdog framework
has gained three more device parameters. Document them.
Signed-off-by: Ahmad Fatoum <a.fatoum@pengutronix.de>
---
Cc: has@pengutronix.de
---
Documentation/user/watchdog.rst | 36 +++++++++++++++++++++++++++++----
1 file changed, 32 insertions(+), 4 deletions(-)
diff --git a/Documentation/user/watchdog.rst b/Documentation/user/watchdog.rst
index 02bd576a89c1..ff400317a0bc 100644
--- a/Documentation/user/watchdog.rst
+++ b/Documentation/user/watchdog.rst
@@ -57,6 +57,9 @@ measured in seconds:
barebox@DPTechnics DPT-Module:/ devinfo wdog0
Parameters:
autoping: 1 (type: bool)
+ priority: 100 (type: uint32)
+ running: 1 (type: enum) (values: "unknown", "1", "0")
+ seconds_to_expire: 7 (type: uint32)
timeout_cur: 7 (type: uint32)
timeout_max: 10 (type: uint32)
@@ -67,6 +70,34 @@ Use barebox' environment to persist these changes between reboots:
nv dev.wdog0.autoping=1
nv dev.wdog0.timeout_cur=7
+Watchdog State
+~~~~~~~~~~~~~~
+
+To check whether a watchdog is currently running, the ``running`` device
+parameter can be consulted. Not all watchdog devices (or their drivers)
+provide the information whether a watchdog was running prior to barebox.
+In that case, the parameter will contain the value ``unknown``.
+
+Watchdogs started by barebox can be monitored using the
+``seconds_to_expire`` parameter. A well-behaving system of watchdog
+device, watchdog driver and clocksource should reset as soon as the
+count down reaches zero.
+
+To manually start a watchdog, :ref:`command_wd` can be used.
+
+Default Watchdog
+~~~~~~~~~~~~~~~~
+
+barebox supports multiple concurrent watchdogs. The default watchdog used
+with :ref:`command_wd`, ``boot.watchdog_timeout`` and :ref:`command_boot`'s
+``-w`` option is the one with the highest positive priority.
+If multiple watchdogs share the same priority, only one will be affected.
+
+The priority is initially set by drivers and can be overridden in the
+device tree or via the ``priority`` device parameter. Normally, watchdogs
+that have a wider effect should be given the higher priority (e.g.
+PMIC watchdog resetting the board vs. SoC's watchdog resetting only itself).
+
Boot Watchdog Timeout
~~~~~~~~~~~~~~~~~~~~~
@@ -85,7 +116,4 @@ or persistently by
nv boot.watchdog_timeout=10
where the used value again is measured in seconds.
-
-On a system with multiple watchdogs, the watchdog with the highest positive
-priority is the one affected by the ``boot.watchdog_timeout`` parameter. If
-multiple watchdogs share the same priority, only one will be started.
+Only the default watchdog will be started.
--
2.29.2
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* Re: [PATCH master 1/2] sandbox: watchdog: don't return positive values from set_timeout
2021-04-26 11:34 [PATCH master 1/2] sandbox: watchdog: don't return positive values from set_timeout Ahmad Fatoum
2021-04-26 11:34 ` [PATCH master 2/2] Documentation: user: watchdog: sync with current state Ahmad Fatoum
@ 2021-05-03 10:38 ` Sascha Hauer
1 sibling, 0 replies; 3+ messages in thread
From: Sascha Hauer @ 2021-05-03 10:38 UTC (permalink / raw)
To: Ahmad Fatoum; +Cc: barebox
On Mon, Apr 26, 2021 at 01:34:07PM +0200, Ahmad Fatoum wrote:
> linux_watchdog_set_timeout() does return alarm(), which can never fail
> and returns either zero or a positive value.
>
> watchdog::set_timeout on the other hand should return either 0 or
> a negative number on error.
>
> Ignore linux_watchdog_set_timeout()'s return value, so
> watchdog_set_timeout propagates the correct value.
>
> This fixes an issue where seconds_to_expire wasn't updated on
> subsequent pings of this watchdog.
>
> Signed-off-by: Ahmad Fatoum <a.fatoum@pengutronix.de>
> ---
> arch/sandbox/board/watchdog.c | 3 ++-
> 1 file changed, 2 insertions(+), 1 deletion(-)
Applied, thanks
Sascha
>
> diff --git a/arch/sandbox/board/watchdog.c b/arch/sandbox/board/watchdog.c
> index 336451282fd3..e1cff7a0bf0b 100644
> --- a/arch/sandbox/board/watchdog.c
> +++ b/arch/sandbox/board/watchdog.c
> @@ -29,7 +29,8 @@ static int sandbox_watchdog_set_timeout(struct watchdog *wdd, unsigned int timeo
> if (timeout > wdd->timeout_max)
> return -EINVAL;
>
> - return linux_watchdog_set_timeout(timeout);
> + linux_watchdog_set_timeout(timeout);
> + return 0;
> }
>
> static int sandbox_watchdog_probe(struct device_d *dev)
> --
> 2.29.2
>
>
> _______________________________________________
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> barebox@lists.infradead.org
> http://lists.infradead.org/mailman/listinfo/barebox
>
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