[PATCH v2 1/4] dt-bindings: firmware: qcom,scm: Document that SCM can be dma-coherent

[Doug Anderson]

Bjorn,

On Fri, Jun 16, 2023 at 8:18 AM Douglas Anderson <dianders at chromium.org> wrote:
>
> Trogdor devices use firmware backed by TF-A instead of Qualcomm's
> normal TZ. On TF-A we end up mapping memory as cacheable. Specifically,
> you can see in Trogdor's TF-A code [1] in qti_sip_mem_assign() that we
> call qti_mmap_add_dynamic_region() with MT_RO_DATA. This translates
> down to MT_MEMORY instead of MT_NON_CACHEABLE or MT_DEVICE.
>
> Let's allow devices like trogdor to be described properly by allowing
> "dma-coherent" in the SCM node.
>
> Signed-off-by: Douglas Anderson <dianders at chromium.org>
> ---
>
> Changes in v2:
> - Bindings change new for v2.
>
>  Documentation/devicetree/bindings/firmware/qcom,scm.yaml | 2 ++
>  1 file changed, 2 insertions(+)

Without this series v6.4 will have a regression where WiFi / LTE won't
work at all on trogdor devices. Any chance you can send up a "Fixes"
pull request with the 4 patches in it? ...or I could try to convince
someone on the SoC tree to land them directly?

Thanks!

-Doug