Re: [PATCH V7 1/2] dt-bindings: firmware: bootstats: Add the dtschema

[Souradeep Chowdhury]

On 7/5/2023 11:47 AM, Krzysztof Kozlowski wrote:
> On 05/07/2023 07:32, Souradeep Chowdhury wrote:
> > Add the device tree bindings for boot stats. This has 2 properties
> > pre-abl-time and abl-time which records the timestamps for boot
> > stats.
> >
> > Signed-off-by: Souradeep Chowdhury <quic_schowdhu@xxxxxxxxxxx>
> > Link: https://lore.kernel.org/linux-arm-kernel/7d397e67-5d56-4975-98af-1ac9746c07f4@xxxxxxxxxxxxxxxx/
> > ---
> >   .../bindings/firmware/qcom,bootstats.yaml     | 38 +++++++++++++++++++
> >   1 file changed, 38 insertions(+)
> >   create mode 100644 Documentation/devicetree/bindings/firmware/qcom,bootstats.yaml
> >
> > diff --git a/Documentation/devicetree/bindings/firmware/qcom,bootstats.yaml b/Documentation/devicetree/bindings/firmware/qcom,bootstats.yaml
> > new file mode 100644
> > index 000000000000..22e697524058
> > --- /dev/null
> > +++ b/Documentation/devicetree/bindings/firmware/qcom,bootstats.yaml
> > @@ -0,0 +1,38 @@
> > +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
> > +%YAML 1.2
> > +---
> > +$id: http://devicetree.org/schemas/firmware/qcom,bootstats.yaml#
> > +$schema: http://devicetree.org/meta-schemas/core.yaml#
> > +
> > +title: Boot Stats
>
> This explains nothing...

Ack

> > +
> > +maintainers:
> > +  - Souradeep Chowdhury <quic_schowdhu@xxxxxxxxxxx>
> > +
> > +description: |
>
> Drop |

Ack

> > +    Qualcomm's proprietary Android boot-loaders capture boot time
>
> Wrong indentation.

Ack
> > +    stats, like the time when the bootloader started execution and
> > +    at what point the bootloader handed over control to the kernel.
> > +    This is captured in the unit of ms in devicetree property.
> > +
> > +properties:
> > +  pre-abl-time:
> > +    description: The property to store the starting point of abl in ms.
>
> String instead of ms? No, this is the craziest idea I saw recently. Use
> -ms suffix.
>
> > +    $ref: /schemas/types.yaml#/definitions/string-array
> > +
> > +  abl-time:
> > +    description: The property to store the duration of abl in ms.
> > +    $ref: /schemas/types.yaml#/definitions/string-array
>
> I have no clue what this entire binding is about. Nothing can bind to
> it, no usage explained. Properties are not used to "store the duration".
> This does not look like suitable for DT, drop entire binding.

This binding was created as per the suggestion on version 6 of the patch 
by Arnd. The idea was that these 2 devicetree properties will be used to 
populate the bootstat values from the bootloader and exposed to the user 
via /sys/firmware/devicetree/ directly.

Details in the link below:-

https://lore.kernel.org/lkml/7d397e67-5d56-4975-98af-1ac9746c07f4@xxxxxxxxxxxxxxxx/T/#mbdc9ad95fcbb5ad7b56c6996a3933899b42d982c

Can you suggest any alternative way to represent this as a binding?

> > +
> > +required:
> > +  - pre-abl-time
> > +  - abl-time
> > +
> > +additionalProperties: false
> > +
> > +examples:
> > +  - |
> > +    bootstats {
> > +        pre-abl-time="17627";
> > +        abl-time="26748";
>
> Missing spaces. Open existing DTS and look at existing coding style.

Ack

> Best regards,
> Krzysztof