Hi Sumit, On Fri, Feb 21, 2025 at 07:16:35PM +0530, Sumit Garg wrote: > On Mon, Feb 17, 2025 at 10:56:58AM -0600, Stuart Yoder wrote: > > > > I don't see how changing TPM discovery to be via FF-A directly > > would improve maintainability. > > You are considering ACPI at this point but when people want to use this > TPM over FF-A on a platform using DT then it will require corresponding > DT bindings. After that each platform has to enable TPM over FF-A in > their corresponding ACPI/DT. All that won't be needed with auto > discovery over FF-A. I hear you and completely agree. However, someone thought it was a good idea to align with other start methods and duplicate information in the TCG ACPI specification. This is definitely a bad idea, as it may contradict the firmware. All we needed was a simple flag to indicate whether FF-A is the start method. It sounds like a classic case of misalignment between specification authors and practical implementation needs. Instead of a simple flag to indicate FF-A as the start method, duplicating information in the TCG ACPI specification seems unnecessary and potentially problematic—especially if it risks conflicting with firmware behavior. Anyway, I can't comment on how we ended up here, but this seems to be the reality. -- Regards, Sudeep
