From: Bruno Thomsen <bruno.thomsen@gmail.com>
To: Alexandre Belloni <alexandre.belloni@bootlin.com>
Cc: "Qiang Zhao" <qiang.zhao@nxp.com>,
"Uwe Kleine-König" <u.kleine-koenig@pengutronix.de>,
"Wim Van Sebroeck" <wim@linux-watchdog.org>,
"Guenter Roeck" <linux@roeck-us.net>,
"linux-watchdog@vger.kernel.org" <linux-watchdog@vger.kernel.org>,
"a.zummo@towertech.it" <a.zummo@towertech.it>,
"robh+dt@kernel.org" <robh+dt@kernel.org>,
"linux-rtc@vger.kernel.org" <linux-rtc@vger.kernel.org>,
"devicetree@vger.kernel.org" <devicetree@vger.kernel.org>,
"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
"kernel@pengutronix.de" <kernel@pengutronix.de>
Subject: Re: [Patch v2 1/3] dt-bindings: rtc: pcf2127: Add bindings for nxp,pcf2127
Date: Thu, 24 Sep 2020 18:59:33 +0200 [thread overview]
Message-ID: <CAH+2xPAi+f2eKdeYiipc=W7eeeNdiXngTLkchpdoFMjJn9Og9w@mail.gmail.com> (raw)
In-Reply-To: <20200924074715.GT9675@piout.net>
Den tor. 24. sep. 2020 kl. 09.47 skrev Alexandre Belloni
<alexandre.belloni@bootlin.com>:
>
> Hi,
>
> On 24/09/2020 07:23:18+0000, Qiang Zhao wrote:
> > > > Yes, you are right, There is not a fundamental solution.
> > > > However it somewhat avoid this situation at least.
> > > >
> > > > And if without this issue,
> > > > is it correct to register a rtc device as watchdog no matter it is used as
> > > watchdog on the board?
> > > > Every time Linux are booted up, watchdog device should be configured to the
> > > right one manually.
> > > > So the patch are useful, even though it is not for the issue.
> > > >
> > > > What should we do to really resolve this issue?
> > >
> > > I still think we need a kernel solution here. I would expect that most assembled
> > > pcf2127 chips are unable to act as a watchdog (i.e. don't have the RST output
> > > connected to something that resets the machine).
> > >
> > > So my favoured solution would be a positive property like:
> > >
> > > has-watchdog;
> > >
> > > or something similar. In my eyes this is definitely something we want to specify
> > > in the device tree because it is a relevant hardware property.
> > > I consider it a bug to give a watchdog device to userspace that isn't functional.
> > >
> > > Best regards
> > > Uwe
> >
> > I strongly agree with you! It should be positive property.
> > However, we couldn't identify which board are using pcf2127 as watchdog,
> > So we are unable to modify the boards' dts to correct (watchdog or not) in this patchset.
> >
> > I noticed that only LS series platforms and imx6 have pcf2127 node, as far as I know, the LS platforms don't use it as watchdog,
> > But I am not sure about imx6
> >
>
> I don't think there is any user upstream and it is recent engouh that we
> can probably make that a positive property.
>
> Bruno, is it ok for you? you are the only know user of the feature.
Hi
This seems like an okay solution to me.
I have a patch series on the way with a new product dts[1] that is
using the watchdog
feature in the pcf2127 chip.
I know that the watchdog feature is used by other products with
out-of-tree dts, but I
will make sure to give them a heads up.
/Bruno
[1] https://lore.kernel.org/linux-arm-kernel/20200923154024.11417-2-bruno.thomsen@gmail.com/
prev parent reply other threads:[~2020-09-24 16:59 UTC|newest]
Thread overview: 39+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-09-21 5:48 [Patch v2 1/3] dt-bindings: rtc: pcf2127: Add bindings for nxp,pcf2127 Qiang Zhao
2020-09-21 5:48 ` [Patch v2 2/3] rtc: pcf2127: add "no-watchdog" property Qiang Zhao
2020-09-21 5:48 ` [Patch v2 3/3] arm64: dts: lx2160a: Add "no-watchdog" property to pcf2127 Qiang Zhao
2020-09-23 9:44 ` [Patch v2 1/3] dt-bindings: rtc: pcf2127: Add bindings for nxp,pcf2127 Alexandre Belloni
2020-09-24 3:20 ` Qiang Zhao
2020-09-24 7:04 ` Uwe Kleine-König
2020-09-24 7:23 ` Qiang Zhao
2020-09-24 7:47 ` Alexandre Belloni
2020-09-24 10:52 ` [PATCH 0/2] rtc: pcf2127: only use watchdog when explicitly available Uwe Kleine-König
2020-09-24 10:52 ` [PATCH 1/2] rtc: pcf2127: move watchdog initialisation to a separate function Uwe Kleine-König
2020-09-27 7:50 ` Bruno Thomsen
2020-09-24 10:52 ` [PATCH 2/2] [RFC] rtc: pcf2127: only use watchdog when explicitly available Uwe Kleine-König
2020-09-27 8:09 ` Bruno Thomsen
2020-09-27 15:54 ` Guenter Roeck
2020-09-28 8:43 ` Uwe Kleine-König
2020-09-28 16:26 ` Guenter Roeck
2020-10-26 7:23 ` [PATCH 0/2] " Qiang Zhao
2020-10-26 20:48 ` Alexandre Belloni
2020-10-26 21:29 ` Guenter Roeck
2020-11-30 9:51 ` Rasmus Villemoes
2020-12-04 9:27 ` Alexandre Belloni
2020-12-11 21:56 ` [PATCH v2 0/3] add reset-source RTC binding, update pcf2127 driver Rasmus Villemoes
2020-12-11 21:56 ` [PATCH v2 1/3] dt-bindings: rtc: add reset-source property Rasmus Villemoes
2020-12-11 22:30 ` Rob Herring
2020-12-11 23:10 ` Rasmus Villemoes
2020-12-17 16:51 ` Rob Herring
2020-12-17 18:12 ` Uwe Kleine-König
2020-12-17 18:23 ` Rasmus Villemoes
2020-12-17 19:02 ` Rob Herring
2020-12-17 20:28 ` Uwe Kleine-König
2020-12-12 9:25 ` Uwe Kleine-König
2020-12-11 21:56 ` [PATCH v2 2/3] rtc: pcf2127: move watchdog initialisation to a separate function Rasmus Villemoes
2020-12-11 21:56 ` [PATCH v2 3/3] rtc: pcf2127: only use watchdog when explicitly available Rasmus Villemoes
2020-12-18 10:10 ` [PATCH v3 0/2] add reset-source RTC binding, update pcf2127 driver Rasmus Villemoes
2020-12-18 10:10 ` [PATCH v3 1/2] dt-bindings: rtc: add reset-source property Rasmus Villemoes
2020-12-18 21:19 ` Rob Herring
2020-12-18 10:10 ` [PATCH v3 2/2] rtc: pcf2127: only use watchdog when explicitly available Rasmus Villemoes
2020-12-19 0:58 ` [PATCH v3 0/2] add reset-source RTC binding, update pcf2127 driver Alexandre Belloni
2020-09-24 16:59 ` Bruno Thomsen [this message]
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