Re: [PATCH 2/3] media: iris: Skip SCM call for non-SCM PAS backend

[Vikash Garodia]

Hi Sumit,

On 9/14/2026 11:44 AM, Sumit Garg wrote:
> Hey Konrad,
>
> On Fri, Sep 11, 2026 at 7:54 PM Konrad Dybcio
> <konrad.dybcio@xxxxxxxxxxxxxxxx> wrote:
> > On 9/11/26 2:38 PM, Sumit Garg wrote:
> > > From: Jorge Ramirez-Ortiz <jorge.ramirez@xxxxxxxxxxxxxxxx>
> > >
> > > qcom_scm_mem_protect_video_var() is only serviced by the SCM backend;
> > > with OP-TEE the TEE owns secure memory protection. Use
> > > qcom_pas_get_backend() to issue the SCM call only for the SCM backend.
> > >
> > > Assisted-by: Copilot:claude-opus-4.8
> > > Signed-off-by: Jorge Ramirez-Ortiz <jorge.ramirez.ortiz@xxxxxxxxx>
> > > Co-developed-by: Sumit Garg <sumit.garg@xxxxxxxxxxxxxxxx>
> > > Signed-off-by: Sumit Garg <sumit.garg@xxxxxxxxxxxxxxxx>
> > > ---
> >
> > [...]
> >
> > > +     /*
> > > +      * qcom_scm_mem_protect_video_var() only applies to the SCM backend;
> > > +      * other backends (e.g. OP-TEE) own secure memory protection and do
> > > +      * not service this call.
> >
> > Can you not just stub it out in TF-A then?
>
> Please don't, we don't want to support these random SCM calls ABI per
> subsystem with the open boot stack. All the config in this case for
> video is handled by OP-TEE itself.

Could you please help me understand the demerit in stubbing it out and 
let that be a dummy ABI in OPTEE world ? that way client driver can 
remain agnostic of the calls being routed to OPTEE or QTEE

> Instead we want to mostly support any subsystem specific TZ use-cases
> as proper client drivers for the TEE subsystem.
>
> -Sumit

Regards,
Vikash