Re: [RFC PATCH 0/2] firmware: qcom: scm: QSEECOM app loading and listener support

[Dawid Wrobel <me@dawidwrobel.com>]

On 2.11.2026 17:27, Haozhen Li wrote:
> Hi Dawid,
> 
> I owe you a sincere apology.

Hi Haozhen. None are needed, but appreciated. I may have come on too
strong but still expected this to turn out to be a mere misunderstanding.


> I would be honored to contribute back to your tree, entirely at your
> discretion:
> 
>  - A PR adding defensive checks for image and listener shared buffers
>    above the 4 GiB physical mark, using the overflow-safe comparison
>    Konrad suggested [2]. For what it is worth, I probed this on
>    sc8280xp by OR-ing bit 32 into an otherwise valid image address:
>    the firmware rejected the APP_START call with an explicit error
>    rather than silently truncating the address, so this is strictly
>    defensive hardening, not a fix for a universal firmware defect.

Absolutely. I did apply a hopefully more idiomatic approach, which
considers the QSEE version, as suggested by Konrad, and sets a
dma_set_coherent_mask(scm->dev, DMA_BIT_MASK(32)) on QSEE older than
TZ.BF.4.0, following what downstream Android qseecom driver does.

>  - Testing on different silicon: I have exercised this transport on
>    sc8280xp with a FocalTech fingerprint TA through repeated
>    load/shutdown cycles and enroll/verify transactions, and would
>    gladly run your tree on this hardware before you file your RFC and
>    provide a Tested-by.

Absolutely and testing on more silicon is what I hoped for before filing
an RFC here, so this is still very much welcome and appreciated.

> On the userspace side, I also maintain an independent D-Bus daemon
> implementing net.reactivated.Fprint directly, without patching fprintd
> or libfprint. Happy to compare notes if that is ever a useful data
> point for the wider fingerprint ecosystem.

Absolutely, let's take it of the ML to reduce the noise and switch to my
repo.

> Thank you for your candid feedback, for CC-ing Sam, and above all for
> the groundwork that made my device bring-up possible in the first
> place.

Appreciate it.

-- 
With Kind Regards,
Dawid Wrobel