Message-ID: <qywqblp4qssd2pvfvecyzb3v2wdcgkd3ffk5lwvf35pcplh45c@yvg7jwjunvtz>
Date: Thu, 11 Dec 2025 01:34:24 +0200
From: Dmitry Baryshkov <dmitry.baryshkov@....qualcomm.com>
To: Bryan O'Donoghue <bryan.odonoghue@...aro.org>
Cc: Vijay Kumar Tumati <vijay.tumati@....qualcomm.com>,
        Hangxiang Ma <hangxiang.ma@....qualcomm.com>,
        Loic Poulain <loic.poulain@....qualcomm.com>,
        Robert Foss <rfoss@...nel.org>, Andi Shyti <andi.shyti@...nel.org>,
        Rob Herring <robh@...nel.org>,
        Krzysztof Kozlowski <krzk+dt@...nel.org>,
        Conor Dooley <conor+dt@...nel.org>, Todor Tomov <todor.too@...il.com>,
        Vladimir Zapolskiy <vladimir.zapolskiy@...aro.org>,
        Mauro Carvalho Chehab <mchehab@...nel.org>,
        linux-arm-msm@...r.kernel.org, devicetree@...r.kernel.org,
        linux-kernel@...r.kernel.org, linux-media@...r.kernel.org,
        Krzysztof Kozlowski <krzk@...nel.org>
Subject: Re: [PATCH v9 1/5] media: dt-bindings: Add CAMSS device for Kaanapali

On Wed, Dec 10, 2025 at 09:45:56PM +0000, Bryan O'Donoghue wrote:
> On 10/12/2025 19:36, Vijay Kumar Tumati wrote:
> > 
> > On 12/10/2025 11:25 AM, Dmitry Baryshkov wrote:
> > > On Wed, Dec 10, 2025 at 09:50:51AM -0800, Vijay Kumar Tumati wrote:
> > > > On 12/8/2025 3:21 PM, Vijay Kumar Tumati wrote:
> > > > > On 12/8/2025 2:48 PM, Dmitry Baryshkov wrote:
> > > > > > On Mon, Dec 08, 2025 at 01:03:06PM -0800, Vijay Kumar Tumati wrote:
> > > > > > > On 12/8/2025 11:53 AM, Dmitry Baryshkov wrote:
> > > > > > > > > +  interconnects:
> > > > > > > > > +    maxItems: 4
> > > > > > > > > +
> > > > > > > > > +  interconnect-names:
> > > > > > > > > +    items:
> > > > > > > > > +      - const: ahb
> > > > > > > > > +      - const: hf_mnoc
> > > > > > > > > +      - const: sf_icp_mnoc
> > > > > > > > > +      - const: sf_mnoc
> > > > > > > > You know... Failure to look around is a sin. What are the names of
> > > > > > > > interconnects used by other devices? What do they actually describe?
> > > > > > > > 
> > > > > > > > This is an absolute NAK.
> > > > > > > Please feel free to correct me here but, a couple things.
> > > > > > > 
> > > > > > > 1. This is consistent with
> > > > > > > Documentation/devicetree/bindings/media/qcom,qcm2290-camss.yaml. no?
> > > > > > I see that nobody noticed an issue with Agatti, Lemans and Monaco
> > > > > > bindings (Krzysztof?)
> > > > > > 
> > > > > > Usually interconnect names describe the blocks that are
> > > > > > connected. Here
> > > > > > are the top results of a quick git grep of interconnect names through
> > > > > > arch/arm64/dts/qcom:
> > > > > > 
> > > > > >       729 "qup-core",
> > > > > >       717 "qup-config",
> > > > > >       457 "qup-memory",
> > > > > >        41 "usb-ddr",
> > > > > >        41 "apps-usb",
> > > > > >        39 "pcie-mem",
> > > > > >        39 "cpu-pcie",
> > > > > >        28 "sdhc-ddr",
> > > > > >        28 "cpu-sdhc",
> > > > > >        28 "cpu-cfg",
> > > > > >        24 "mdp0-mem",
> > > > > >        17 "memory",
> > > > > >        14 "ufs-ddr",
> > > > > >        14 "mdp1-mem",
> > > > > >        14 "cpu-ufs",
> > > > > >        13 "video-mem",
> > > > > >        13 "gfx-mem",
> > > > > > 
> > > > > > I hope this gives you a pointer on how to name the interconnects.
> > > > > > 
> > > > > > > 2. If you are referring to some other targets that use, "cam_"
> > > > > > > prefix, we
> > > > > > > may not need that , isn't it? If we look at these interconnects
> > > > > > > from camera
> > > > > > > side, as you advised for other things like this?
> > > > > > See above.
> > > > > I see, so the names cam-cfg, cam-hf-mem, cam-sf-mem, cam-sf-icp-mem
> > > > > should be ok?
> > > > > 
> > > > > Or the other option, go exactly like
> > > > > Documentation/devicetree/bindings/media/qcom,sc8280xp-camss.yaml.
> > > > > 
> > > > > What would you advise?
> > > > > 
> > > > To keep it consistent with the previous generations and still
> > > > represent the
> > > > block name, we will go ahead with the style in qcom,sc8280xp-
> > > > camss.yaml. If
> > > > anyone has any concerns, please do let us know.
> > > Krzysztof, Bryan, your opinion? My preference would be to start using
> > > sensible names, but I wouldn't enforce that.
> > > 
> > > > > > > > > +
> > > > > > > > > +  iommus:
> > > > > > > > > +    items:
> > > > > > > > > +      - description: VFE non-protected stream
> > > > > > > > > +      - description: ICP0 shared stream
> > > > > > > > > +      - description: ICP1 shared stream
> > > > > > > > > +      - description: IPE CDM non-protected stream
> > > > > > > > > +      - description: IPE non-protected stream
> > > > > > > > > +      - description: JPEG non-protected stream
> > > > > > > > > +      - description: OFE CDM non-protected stream
> > > > > > > > > +      - description: OFE non-protected stream
> > > > > > > > > +      - description: VFE / VFE Lite CDM non-protected stream
> > > > > > > > This will map all IOMMUs to the same domain. Are
> > > > > > > > you sure that this is
> > > > > > > > what we want? Or do we wait for iommu-maps to be fixed?
> > > > Yes, when it is available, we can start using iommu-maps to
> > > > create separate
> > > > context banks.
> > > It would be necessary to justify removing items from the list. Wouldn't
> > > it be better to map only necessary SIDs now and add other later once we
> > > have iommu-maps?
> > I will let Bryan take the call on this. He was the one who wanted all
> > the SIDs in the bindings. Hi @Bryan, if you can kindly share your
> > thoughts on this and the interconnect naming, we will go ahead and push
> > rev 10 for this. I believe we have taken care of other things. Thank
> > you.
> > > 
> 
> Since when are we delaying patches for future patches that may land never ?
> 
> I'm fine with whatever clock name changes you can agree with Krzysztof but
> it seems a bit ironic to me to be given feedback to "align with previous
> dts" to then have the result be further change.
> 
> I'd like a bit of stability and consistency TBH.

:-)

-- 
With best wishes
Dmitry

Powered by blists - more mailing lists