Subject: Re: [PATCH v3 00/15] firmware: qcom: Add OP-TEE PAS service support

From: Sumit Garg <[email-masked]>
Date: Tue, 7 Apr 2026 10:24:44 +0530

Hi Bjorn,

On Mon, Apr 06, 2026 at 10:09:27AM -0500, Bjorn Andersson wrote:
> On Fri, Mar 27, 2026 at 06:40:28PM +0530, Sumit Garg wrote:
> > From: Sumit Garg <[email-masked]>
> > 
> > Qcom platforms has the legacy of using non-standard SCM calls
> > splintered over the various kernel drivers. These SCM calls aren't
> > compliant with the standard SMC calling conventions which is a
> > prerequisite to enable migration to the FF-A specifications from Arm.
> > 
> 
> Please get our colleagues involved in this discussion, because this
> non-SCM interface does not match the direction we are taking.

I thought I have already involved folks from QTEE perspective (Apurupa
and Sree) actively working on FF-A implementation aligned to this
interface. It would have been better if you could let me know where is
the direction mismatch here. In case there is a better alternative
design proposal for PAS service with FF-A, I would be happy to hear
that.

Anyhow for the legacy SoCs like KLMT, we really don't have any
alternative but have to stick to existing QTEE PAS design with OP-TEE
providing as an alternative backend. Surely we want to support loading
of existing signed firmware present in linux-firmware repo for KLMT with
OP-TEE being the TZ.

-Sumit