On 28/02/2024 15:02, Sudeep Holla wrote: > On Wed, Feb 28, 2024 at 02:27:30PM +0100, Ulf Hansson wrote: >> On Mon, 26 Feb 2024 at 15:24, Nikunj Kela <quic_nkela@xxxxxxxxxxx> wrote: >>> >>> Hi Sudeep, >>> >>> I would like to conclude on this thread. I was discussing this with Ulf. >>> He thinks that using the domain names to identify if platform is >>> abstracting clocks etc. are not scalable and sufficient. Instead he >>> thinks that the change in the interface to OS(and FW) is a good >>> candidate for a new compatible(even though HW is same). Even for SCMI, >>> we do change phandle in DT to SCMI protocol phandle so that is like a >>> different platform altogether. Could you please let me know if you still >>> think that using a different compatible in this case is not warranted. >> >> My apologies for joining this discussion at this late state. Yet, I >> just wanted to confirm what Nikunj said above. >> >> In the end we are indeed talking about adding a new platform, as >> changing the FW interface from a QCOM proprietary one into SCMI, >> simply requires updates to a DTS file(s) that is platform specific. >> > > The way I read this sounds like all this are platform specific and need > new compatible. > >> That said, it also seems reasonable to me to use a compatible string, >> to allow us to describe the update of HW for various affected devices. >> > > While I agree with the above statement, it depends on what you refer as > update of HW above. It is all Qcom specific and there is so much turn > between SoCs that this shouldn't matter but I would like to take example > and describe what I initially mentioned/argued against. > > Lets us assume 2 SoCs: A and B. A is old and didn't use SCMI while B is > new and migrated to use SCMI. Now let us assume both A and B SoCs have > exact same version/revision of an IP: X. Now just because B uses SCMI, > should X have one compatible to be used in A and another in B. That > doesn't sound right IMO. That's trivial to answer, because these are different SoCs. Compatibles are SoC specific and every SoC-IP-block needs its compatible. Rob was repeating this many times that versioned compatibles are discouraged. > > If X on A has to manage clocks and voltage separately while the same X > on B uses SCMI to manage them together as performance domain, then the > presence(or absence) of those properties must indicate the difference and > not a change in compaible for the IP X. But it is upto Qcom platform > maintainer, IP driver maintainer and DT maintainers to decide, I will > leave that them. I just wanted to express my opinion on the matter. Best regards, Krzysztof
