On Thu, Apr 11, 2024 at 5:43 AM Krzysztof Kozlowski <krzk@xxxxxxxxxx> wrote:
>
> On 11/04/2024 12:09, Jon Hunter wrote:
> >
> > On 10/04/2024 07:18, Krzysztof Kozlowski wrote:
> >> On 09/04/2024 10:23, Jon Hunter wrote:
> >>> The dtbs_check reports that the 'dma-coherent' property is "unevaluated
> >>> and invalid" for the host1x@13e00000 device on Tegra194 and Tegra234
> >>> platforms. Fix this by updating the dt-binding document for host1x to
> >>> add the 'dma-coherent' property for these devices.
> >>
> >> That's not really proper reason. What if DTS is wrong? The reason could
> >> be if device is actually DMA coherent...
> >
> > In this case the DTS is correct. I guess I should have been more
> > explicit about that.
> >
> >>> Fixes: 361238cdc525 ("arm64: tegra: Mark host1x as dma-coherent on Tegra194/234")
> >>> Signed-off-by: Jon Hunter <jonathanh@xxxxxxxxxx>
> >>> ---
> >>> .../bindings/display/tegra/nvidia,tegra20-host1x.yaml | 11 +++++++++++
> >>> 1 file changed, 11 insertions(+)
> >>>
> >>> diff --git a/Documentation/devicetree/bindings/display/tegra/nvidia,tegra20-host1x.yaml b/Documentation/devicetree/bindings/display/tegra/nvidia,tegra20-host1x.yaml
> >>> index 94c5242c03b2..3563378a01af 100644
> >>> --- a/Documentation/devicetree/bindings/display/tegra/nvidia,tegra20-host1x.yaml
> >>> +++ b/Documentation/devicetree/bindings/display/tegra/nvidia,tegra20-host1x.yaml
> >>> @@ -177,6 +177,15 @@ allOf:
> >>>
> >>> required:
> >>> - reg-names
> >>> + - if:
> >>> + properties:
> >>> + compatible:
> >>> + contains:
> >>> + enum:
> >>> + - nvidia,tegra194-host1x
> >>> + then:
> >>> + properties:
> >>> + dma-coherent: true
> >>
> >> Do not define properties in allOf. Put it in top-level. If not all
> >> devices are DMA coherent, you can disallow it for certain variants (:false).
> >
> >
> > So for host1x we currently have the following devices supported ...
> >
> > properties:
> > compatible:
> > oneOf:
> > - enum:
> > - nvidia,tegra20-host1x
> > - nvidia,tegra30-host1x
> > - nvidia,tegra114-host1x
> > - nvidia,tegra124-host1x
> > - nvidia,tegra210-host1x
> > - nvidia,tegra186-host1x
> > - nvidia,tegra194-host1x
> > - nvidia,tegra234-host1x
> >
> > - items:
> > - const: nvidia,tegra132-host1x
> > - const: nvidia,tegra124-host1x
> >
> >
> > Now only the Tegra194 and Tegra234 are coherent (which are the latest
> > devices). So rather than add this to the top and then filter out all
> > those that are not supported, I opted for the above because there is
> > only 2 devices that need this. Admittedly, as much as I like the yaml
> > bindings, for things like this, it is not really clear which is the best
> > way to handle, so appreciate the guidance.
>
> The way to handle is that you must define properties top-level.
>
> For simplification you could keep the if which duplicates the
> dma-coherent:true but add else: which forbids it
>
> if:
> ...
> then:
> properties:
> dma-coherent: true
I think just 'then: true' will work here.
Technically, json-schema allows:
if:
...
else:
...
Actually any combination of the 3 keywords present is valid, but we've
disallowed the above and other nonsense ones in the meta-schema. We
can always relax things if there's a need.
Rob
