Re: [PATCH v2 1/5] dt-bindings: firmware: qcom,scm: Document SDI disable

From: Rob Herring
Date: Mon Aug 21 2023 - 15:31:58 EST


On Wed, Aug 16, 2023 at 08:15:54AM +0200, Krzysztof Kozlowski wrote:
> On 15/08/2023 15:59, Robert Marko wrote:
> > IPQ5018 has SDI (Secure Debug Image) enabled by TZ by default, and that
> > means that WDT being asserted or just trying to reboot will hang the board
> > in the debug mode and only pulling the power and repowering will help.
> > Some IPQ4019 boards like Google WiFI have it enabled as well.
> >
> > So, lets add a boolean property to indicate that SDI should be disabled.
> >
> > Signed-off-by: Robert Marko <robimarko@xxxxxxxxx>
> > ---
> > Documentation/devicetree/bindings/firmware/qcom,scm.yaml | 8 ++++++++
> > 1 file changed, 8 insertions(+)
> >
> > diff --git a/Documentation/devicetree/bindings/firmware/qcom,scm.yaml b/Documentation/devicetree/bindings/firmware/qcom,scm.yaml
> > index 4233ea839bfc..bf753192498a 100644
> > --- a/Documentation/devicetree/bindings/firmware/qcom,scm.yaml
> > +++ b/Documentation/devicetree/bindings/firmware/qcom,scm.yaml
> > @@ -89,6 +89,14 @@ properties:
> > protocol to handle sleeping SCM calls.
> > maxItems: 1
> >
> > + qcom,sdi-disable:
>
> The property should describe rather current hardware/firmware state,
> instead of expressing your intention for OS what to do. Therefore rather:
> qcom,sdi-enabled
> or
> qcom,secure-debug-image

Why can't you just disable SDI unconditionally when going into debug
mode? Is doing that when not enabled going to crash the system or
something?

Rob