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

["Padhi, Beleswar" <b-padhi@ti.com>]

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