Re: [PATCH v3 01/11] dt-bindings: reserved-memory: Document Tegra VPR

On Thu, Jul 2, 2026 at 7:58 AM Thierry Reding [off-list ref] wrote:

On Wed, Jul 01, 2026 at 02:53:10PM -0500, Rob Herring (Arm) wrote:

quoted

On Wed, 01 Jul 2026 18:08:12 +0200, Thierry Reding wrote:

quoted

From: Thierry Reding <redacted>

The Video Protection Region (VPR) found on NVIDIA Tegra chips is a
region of memory that is protected from CPU accesses. It is used to
decode and play back DRM protected content.

It is a standard reserved memory region that can exist in two forms:
static VPR where the base address and size are fixed (uses the "reg"
property to describe the memory) and a resizable VPR where only the
size is known upfront and the OS can allocate it wherever it can be
accomodated.

Reviewed-by: Rob Herring (Arm) <robh@kernel.org>
Signed-off-by: Thierry Reding <redacted>
---
Changes in v2:
- add examples for fixed and resizable VPR
---
 .../nvidia,tegra-video-protection-region.yaml      | 76 ++++++++++++++++++++++
 1 file changed, 76 insertions(+)

My bot found errors running 'make dt_binding_check' on your patch:

yamllint warnings/errors:

dtschema/dtc warnings/errors:
/builds/robherring/dt-review-ci/linux/Documentation/devicetree/bindings/reserved-memory/nvidia,tegra-video-protection-region.example.dtb: protected@2a8000000 (nvidia,tegra-video-protection-region): reg: [[2, 2818572288], [0, 1879048192]] is too long
      from schema $id: http://devicetree.org/schemas/reserved-memory/nvidia,tegra-video-protection-region.yaml
/builds/robherring/dt-review-ci/linux/Documentation/devicetree/bindings/reserved-memory/nvidia,tegra-video-protection-region.example.dtb: protected@2a8000000 (nvidia,tegra-video-protection-region): Unevaluated properties are not allowed ('no-map', 'reg' were unexpected)
      from schema $id: http://devicetree.org/schemas/reserved-memory/nvidia,tegra-video-protection-region.yaml

Any ideas why that second error shows up? It turns out that it goes away
when the first one is fixed (which admittedly is a stupid mistake), but
I spent quite a bit of time looking for a fix before realizing that it's
only a side-effect of the first.

If a property fails validation in a referenced schema, then everything
in that referenced schema is considered not evaluated. So then
unevaluatedProperties is applied to the properties only in the
referenced schema. That's why 'no-map' is also unevaluated. Just a
quirk of how json-schema works...

Rob