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

[Jorge Ramirez]

On 07/04/26 15:14:22, Trilok Soni wrote:
> On 4/6/2026 4:42 AM, Sumit Garg wrote:
> > 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 <sumit.garg@xxxxxxxxxxxxxxxx>
> >>>
> >>> 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.

the patchset cover letter + the commit message + the OP-TEE pull request
being referenced gives the ilusion to users that with the current set
they will get something functional (they will get a broken video
platform instead if they try to use OP-TEE).

That was the point I was making: IMO the commit message walks on a thin
line of "completeness"

QTEE and OP-TEE at this time implement different use cases (Venus with
QTEE runs with Linux on EL1 , OP-TEE runs with Linux on EL2). So maybe
worth mentioning this divergence.

> > 
> >>
> >> 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.
> 
> Vikas and team depends on some of the IOMMU patches to get accepted 
> before they enable the EL2 venus support. Please reach out to him
> and Prakash Gupta at Qualcomm.

isn't Vikash in this thread, he can ping me too no :) ? but sure, we'll
synch later