Re: [PATCH v14 3/9] remoteproc: qcom: add hexagon based WCSS secure PIL driver

On Tue, Aug 04, 2026 at 04:49:17PM +0530, Vignesh Viswanathan wrote:
> 
> 
> On 8/3/2026 6:14 PM, Mukesh Ojha wrote:
> > On Mon, Aug 03, 2026 at 04:16:09PM +0530, Varadarajan Narayanan wrote:
> >> From: Vignesh Viswanathan <[email protected]>
> >>
> >> Add support to bring up hexagon based WCSS using secure PIL. All IPQxxxx
> >> SoCs support secure Peripheral Image Loading (PIL).
> >>
> >> Secure PIL image is signed firmware image which only trusted software such
> >> as TrustZone (TZ) can authenticate and load. Linux kernel will send a
> >> Peripheral Authentication Service (PAS) request to TZ to authenticate and
> >> load the PIL images.
> >>
> >> In order to avoid overloading the existing WCSS driver or PAS driver, we
> >> came up with this new PAS based IPQ WCSS driver.
> > 
> > Can you tell why you need another driver if you are using the same PAS
> > method and it is using more of everything what PAS already
> > supports ?
> > 
> 
> Hi Mukesh,
> 
> We just use pas_auth_and_reset and pas_shutdown APIs and do not need
> the entire framework provided by the PAS driver for IPQ WCSS.

But you are using qcom_mdt_load() in wcss_sec_load(), which internally will
call pas_init and memset SMCs.

> 
> Also, feedback from Bjorn in [1] was to have separate driver
> instead of overloading existing WCSS driver.

That's a very old thread, 5 years is a long time. We can still revisit why
you need a separate driver. If you already have all the stuff required to
be a PAS driver, why not use that?

> 
> [1] https://lore.kernel.org/all/[email protected]/
>

-Mukesh