Re: [PATCH v3 1/6] dt-bindings: iommu: arm,smmu: Document interconnects property

[Bjorn Andersson <andersson@kernel.org>]

On Wed, Jul 08, 2026 at 08:22:00PM +0530, Bibek Kumar Patro wrote:
> 
> 
> On 7/7/2026 10:12 PM, Dmitry Baryshkov wrote:
> > On Tue, Jul 07, 2026 at 06:06:59PM +0530, Bibek Kumar Patro wrote:
> > > 
> > > 
> > > On 7/6/2026 11:09 PM, Dmitry Baryshkov wrote:
> > > > On Mon, Jul 06, 2026 at 10:26:34PM +0530, Bibek Kumar Patro wrote:
> > > > > Some SoC implementations require a bandwidth vote on an interconnect
> > > > > path before the SMMU register space is accessible. Add the optional
> > > > 
> > > > Why is it limited only to those SoCs? Is it also applicable to other
> > > > Qualcomm SoCs?
> > > > 
> > > 
> > > I was hoping to keep this series focused on the core infrastructure
> > > changes: the bindings, base ICC bandwidth-voting support, and DT
> > > interconnect properties for the platforms currently supported on
> > > Qualcomm Linux and have been validated so far.
> > > 
> > > The additional targets have not been tested yet, so I'd prefer
> > > to add their support in a separate follow-up series once validation
> > > is complete, rather than growing this series further. WDYT?
> > 
> > Then it should be a part of the commit message. All SoCs since SDM12345
> > need to vote on the interconnect (and then, in the cover letter mention
> > that you convert only a few of the SoCs). We possibly can help with
> > testing on other platforms.
> > 
> 
> Ack, sounds reasonable.
> I'll add the first platform onwards which interconnect voting is required in
> commit description.

But to what degree is this related to a specific set of platforms? If we
look ahead, aren't we expecting the list to grow to include all
platforms in the end - resulting in a lot of noise and churn.

Can you give an example of a platform where there is no interconnect
path to vote for here or where it would be harmful to do so?

> And update the cover letter to clarify that this series adds
> support for the Qualcomm Linux-supported targets available today, and
> the list will be expanded in follow-up series as additional platforms
> are enabled.
> 

The binding should not reflect what has been implemented and verified in
Linux, it defines the contract between DeviceTree and the OS.

Regards,
Bjorn

> Thanks & regards,
> Bibek
> 
> > > > > 'interconnects' property to the binding to allow platform DT nodes
> > > > > to describe this path.
> > > > > 
> > > > > Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@oss.qualcomm.com>
> > > > > Signed-off-by: Bibek Kumar Patro <bibek.patro@oss.qualcomm.com>
> > > > > ---
> > > > >    .../devicetree/bindings/iommu/arm,smmu.yaml        | 27 ++++++++++++++++++++++
> > > > >    1 file changed, 27 insertions(+)
> > > > > 
> > 
>