diff mbox series

[4.19.y-cip,2/6] arm64: dts: renesas: r8a774c0-cat874: Add RWDT support

Message ID 1563200930-39297-3-git-send-email-biju.das@bp.renesas.com (mailing list archive)
State Accepted
Headers show
Series Add LED/WDT support | expand

Commit Message

Biju Das July 15, 2019, 2:28 p.m. UTC 
From: Fabrizio Castro <fabrizio.castro@bp.renesas.com>

commit 79223ca1f57776d2770da9561c26cc2f2dd42205 upstream.

Enable RWDT and use 60 seconds as default timeout.

Signed-off-by: Fabrizio Castro <fabrizio.castro@bp.renesas.com>
Reviewed-by: Chris Paterson <chris.paterson2@renesas.com>
Signed-off-by: Simon Horman <horms+renesas@verge.net.au>
Signed-off-by: Biju Das <biju.das@bp.renesas.com>
---
 arch/arm64/boot/dts/renesas/r8a774c0-cat874.dts | 5 +++++
 1 file changed, 5 insertions(+)

Comments

Pavel Machek July 16, 2019, 8:27 p.m. UTC | #1 
On Mon 2019-07-15 15:28:46, Biju Das wrote:
> From: Fabrizio Castro <fabrizio.castro@bp.renesas.com>
> 
> commit 79223ca1f57776d2770da9561c26cc2f2dd42205 upstream.
> 
> Enable RWDT and use 60 seconds as default timeout.

So this will reboot machine if userspace does not ping it within 60
seconds by default?

Will that break user configurations that worked up till now, but do
not contain watchdog support?

Do we care?

Thanks,
								Pavel

> @@ -137,6 +137,11 @@
>  	};
>  };
>  
> +&rwdt {
> +	timeout-sec = <60>;
> +	status = "okay";
> +};
> +
>  &scif2 {
>  	pinctrl-0 = <&scif2_pins>;
>  	pinctrl-names = "default";
Biju Das July 17, 2019, 7:40 a.m. UTC | #2 
Hi Pavel,

Thanks for the feedback.

> Subject: Re: [cip-dev] [PATCH 4.19.y-cip 2/6] arm64: dts: renesas: r8a774c0-
> cat874: Add RWDT support
> 
> On Mon 2019-07-15 15:28:46, Biju Das wrote:
> > From: Fabrizio Castro <fabrizio.castro@bp.renesas.com>
> >
> > commit 79223ca1f57776d2770da9561c26cc2f2dd42205 upstream.
> >
> > Enable RWDT and use 60 seconds as default timeout.
> 
> So this will reboot machine if userspace does not ping it within 60 seconds by
> default?

Yes,  if you enable watchdog  in user space and there is no ping activity for 60 sec.
We can verify this by using the below  command

cat > /dev/watchdog0 & for i in $(seq 100); do echo $i; sleep 1; done

> Will that break user configurations that worked up till now, but do not
> contain watchdog support?
> 
> Do we care?
> 

 As per  [1]
- timeout-sec : Contains the watchdog timeout in seconds
[1] https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/Documentation/devicetree/bindings/watchdog/renesas-wdt.txt?h=v5.2

If time-out is not specified, then it uses the default timeout mentioned by the driver.

Regards,
Biju
> 
> > @@ -137,6 +137,11 @@
> >  	};
> >  };
> >
> > +&rwdt {
> > +	timeout-sec = <60>;
> > +	status = "okay";
> > +};
> > +
> >  &scif2 {
> >  	pinctrl-0 = <&scif2_pins>;
> >  	pinctrl-names = "default";
> 
> --
> DENX Software Engineering GmbH,      Managing Director: Wolfgang Denk
> HRB 165235 Munich, Office: Kirchenstr.5, D-82194 Groebenzell, Germany
Pavel Machek July 17, 2019, 9:41 a.m. UTC | #3 
Hi!

> > cat874: Add RWDT support
> > 
> > On Mon 2019-07-15 15:28:46, Biju Das wrote:
> > > From: Fabrizio Castro <fabrizio.castro@bp.renesas.com>
> > >
> > > commit 79223ca1f57776d2770da9561c26cc2f2dd42205 upstream.
> > >
> > > Enable RWDT and use 60 seconds as default timeout.
> > 
> > So this will reboot machine if userspace does not ping it within 60 seconds by
> > default?
> 
> Yes,  if you enable watchdog  in user space and there is no ping activity for 60 sec.
> We can verify this by using the below  command

Aha. But if userspace does nothing, no reboot happens. Good.

Best regards,
								Pavel
diff mbox series

Patch

diff --git a/arch/arm64/boot/dts/renesas/r8a774c0-cat874.dts b/arch/arm64/boot/dts/renesas/r8a774c0-cat874.dts
index af396bb..9241407 100644
--- a/arch/arm64/boot/dts/renesas/r8a774c0-cat874.dts
+++ b/arch/arm64/boot/dts/renesas/r8a774c0-cat874.dts
@@ -137,6 +137,11 @@ 
 	};
 };
 
+&rwdt {
+	timeout-sec = <60>;
+	status = "okay";
+};
+
 &scif2 {
 	pinctrl-0 = <&scif2_pins>;
 	pinctrl-names = "default";