Re: [PATCH 2/4] dt-bindings: display: tegra: Add channel/syncpoint range properties
From: Krzysztof Kozlowski
Date: Fri Jun 26 2026 - 06:26:24 EST
On Thu, Jun 25, 2026 at 06:26:43PM +0900, Mikko Perttunen wrote:
> On Thursday, June 25, 2026 5:36 PM Krzysztof Kozlowski wrote:
> > On Mon, Jun 22, 2026 at 05:22:51PM +0900, Mikko Perttunen wrote:
> > > Channels and syncpoints available may be limited when other system
> >
> > What are channels and syncpoints?
>
> Very host1x-specific hardware resources. Somewhat close to GPU channels
> and semaphores / fences if you're familiar with those.
>
> >
> > > components are using them. Add properties nvidia,channels and
> > > nvidia,syncpoints to limit the range of usable channels and/or
> > > syncpoints.
> >
> > Why isn't this deducible from the compatible?
>
> When Host1x is partitioned, the hypervisor (or other software entity
> with access to the non-vm host1x register regions) can configure which
> channels and syncpoints are available to each partition arbitrarily.
So you will have different boards for the same SoC with different
values?
>
> How that partitioning was done is not discoverable through hardware
> directly, so we need to pass that information through device tree.
>
> >
> > Also, nvidia,channels is too broad/generic. This is not ADC, right? And
> > channels is a common term in IIO. And in few other cases.
>
> It's not ADC. Yes, it's a common term in a lot of contexts. I can call
> it nvidia,host1x-channels if you prefer but that seems a bit redundant
> given the context.
host1x is indeed poor, but maybe there is some way to be a bit more
descriptive? message-channels?
Best regards,
Krzysztof