Re: [PATCH 2/6] dt-bindings: arm: keystone: ti,sci: Add ti,tda54-sci-pdm compatible

[Padhi, Beleswar]

On 10/2/2026 3:09 PM, Krzysztof Kozlowski wrote:
> On 02/10/2026 11:30, Padhi, Beleswar wrote:
> > On 10/2/2026 12:01 PM, Krzysztof Kozlowski wrote:
> > > On Thu, Oct 01, 2026 at 01:11:27AM +0530, Beleswar Padhi wrote:
> > > > The previous TI K2G and K3 architectures were tightly coupled systems in
> > > > terms of Safety and Security. All the TI-SCI messages from HLOS (Linux)
> > > > were sent to a single sec proxy thread terminating at the core running
> > > > Safety service (DM). In K2G systems, DM handled both Safety & Security
> > > > requests by itself. Whereas in K3 systems, DM serviced the Safety
> > > > requests itself, and forwarded the Security requests to core running
> > > > Security service (TIFS) on the HLOS's behalf. This posed various
> > > > limitations:
> > > >      a. Increased latency: An extra forwarding hop through DM adds latency
> > > >         in requests and responses.
> > > >      b. Freedom From Interference (FFI) concerns: Having Safety service
> > > >         proxy Security's requests (& vice versa) undermines the isolation
> > > >         and FFI of the system.
> > > >      c. Potential Deadlock Scenario: Forwarding messages between Safety
> > > >         and Security cores can result in a deadlock if there are circular
> > > >         dependencies.
> > > >
> > > > To eliminate all the above limitations, the TI TDA54 class of SoCs
> > > > introduce an architectural change: Isolation of Security and Safety
> > > > services. To realize this enhanced isolation in hardware, two
> > > > independent sec proxy threads are now provided for HLOS to communicate
> > > > separately with the Security and Safety cores respectively. And the
> > > > TI-SCI message forwarding has been eliminated in Software. The System
> > > > Firmware ABI5.0 version necessitates this improved isolation and FFI
> > > > change.
> > > I don't get at all how above description helps to understand this patch
> > > and this new compatible, except that this is not compatible with old
> > > variants.
> >
> > You just answered your own question.
> >
> > >    So 30 lines of text instead of 3?
> >
> > The existing system controllers have been compatible in all TI SoCs
> > for over 10+ years since Keystone generations. Using 30 lines of
> > text to explain "why" the new system controller is not compatible
> > with old variants is worth it.
> If you decide to spam us with a lot of description, including marketing
> crap ("To realize this enhanced isolation in hardware", "this improved
> isolation")


I am a Open Source Developer at TI. Marketing about TI Product/Hardware
is of no interest to me, neither is my intent. I was just describing why
& how the hardware has changed. If it gives the impression of
marketing, then sure, I will drop the "crap" to not waste your time.

Thanks,
Beleswar

>   instead of writing concise and precise messages, accept the
> outcome of maintainers choosing to allocate their time in "improved way".
>
> Best regards,
> Krzysztof