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From:   ChiYuan Huang <u0084500@gmail.com>
Date:   Wed, 8 Jun 2022 11:04:10 +0800
Message-ID: <CADiBU39yXrB+yQeXHv0ToceCeG+w_TT2JkzP83rzkf+j-53Zfg@mail.gmail.com>
Subject: Re: [PATCH 1/4] dt-binding: mfd: Add Richtek RT5120 PMIC support
To:     Mark Brown <broonie@kernel.org>
Cc:     Rob Herring <robh+dt@kernel.org>,
        Krzysztof Kozlowski <krzysztof.kozlowski+dt@linaro.org>,
        Lee Jones <lee.jones@linaro.org>, dmitry.torokhov@gmail.com,
        Liam Girdwood <lgirdwood@gmail.com>,
        cy_huang <cy_huang@richtek.com>,
        "open list:OPEN FIRMWARE AND FLATTENED DEVICE TREE BINDINGS" 
        <devicetree@vger.kernel.org>, lkml <linux-kernel@vger.kernel.org>,
        linux-input@vger.kernel.org
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Mark Brown <broonie@kernel.org> =E6=96=BC 2022=E5=B9=B46=E6=9C=888=E6=97=A5=
 =E9=80=B1=E4=B8=89 =E4=B8=8A=E5=8D=883:02=E5=AF=AB=E9=81=93=EF=BC=9A
>
> On Tue, Jun 07, 2022 at 01:52:38PM +0800, cy_huang wrote:
>
> > +  richtek,enable-undervolt-hiccup:
> > +    type: boolean
> > +    description: |
> > +      If used, under voltage protection trigger hiccup behavior, else =
latchup as
> > +      default
> > +
> > +  richtek,enable-overvolt-hiccup:
> > +    type: boolean
> > +    description:
> > +      Like as 'enable-uv-hiccup', it configures over voltage protectio=
n to
> > +      hiccup, else latchup as default
>
> Why would we not want to have these enabled?  Unless there's some cost
> to having them on it seems safer and more helpful to look for problems
> with regulation all the time, it might help debug a system.
The default latch mode would be safer during power rails boot up.
If during power rails boot up, any oc/ov protection triggered, latch
mode will keep power rails off.
Only toggle the external pin to re-enable can trigger next power up.
Like as your said, hiccup can help the debug for this kind of HW issue.
So after all power rails and system booted up to make the user choose
the hiccup option.
That's why the property here to enable hiccup mode.