Subject: Re: [PATCH v3 11/15] media: qcom: Switch to generic PAS TZ APIs

From: Sumit Garg <[email-masked]>
Date: Mon, 6 Apr 2026 17:12:42 +0530

Hi Jorge,

On Fri, Apr 03, 2026 at 11:37:07AM +0200, Jorge Ramirez wrote:
> On 27/03/26 18:40:39, Sumit Garg wrote:
> > From: Sumit Garg <[email-masked]>
> > 
> > Switch qcom media client drivers over to generic PAS TZ APIs. Generic PAS
> > TZ service allows to support multiple TZ implementation backends like QTEE
> > based SCM PAS service, OP-TEE based PAS service and any further future TZ
> > backend service.
> 
> OP-TEE based PAS service relies on the linux driver to configure the
> iommu (just as it is done on the no_tz case). This generic patch does
> not cover that requirement.

That's exactly the reason why the kodiak EL2 dtso disables venus by
default in patch #1 due to missing IOMMU configuration.

> 
> Because of that, it is probably better if the commit message doesnt
> mention OP-TEE and instead maybe indicate that PAS wll support TEEs that
> implement the same restrictions that QTEE (ie, iommu configuration).

The scope for this patch is to just adopt the generic PAS layer without
affecting the client functionality.

> 
> I can send an RFC for OP-TEE support based on the integration work being
> carried out here [1]

@Vikash may know better details about support for IOMMU configuration
for venus since it's a generic functionality missing when Linux runs in
EL2 whether it's with QTEE or OP-TEE.

However, feel free to propose your work to initiate discussions again.

> 
> [1] https://github.com/OP-TEE/optee_os/pull/7721#discussion_r3016923507

-Sumit