SSDT-SBUS-MCHC - is it always needed?

[atanvarno]

One thing I wondered for quite a while regarding SMBus support.

At the end of the Dortania article, there's a terminal command to check is the SSDT working:

kextstat | grep -E "AppleSMBusController|AppleSMBusPCI"

I disabled the SSDT and checked output from this command:

% kextstat | grep -E "AppleSMBusController|AppleSMBusPCI"

Executing: /usr/bin/kmutil showloaded
No variant specified, falling back to release
  118    0 0xffffff7f9ad2a000 0x1000     0x1000     com.apple.driver.AppleSMBusPCI (1.0.14d1) A538CDCE-162C-3B75-9D2D-70596BEDB2FC <14 6 5 3>
  161    1 0xffffff7f9ad20000 0x6000     0x6000     com.apple.driver.AppleSMBusController (1.0.18d1) 7C776793-9706-3C5E-8F36-9C3C09C784F0 <160 14 13 6 5 3>
`

Not sure about that message about variant but it seems SMBus is ready and kexts loaded. Is it correct to conclude SSDT is not needed if this case?
(I'm running Big Sur 11.6)

 

[atanvarno]

Hm, but when you check in IORegExplorer, SMBus is gone from IOService.
Thus it seems that checking just for kexts may not be enough.

I'm confused now, will need to look at iOReg from real MacPro.

 

[AudioGod]

It’s not vitally needed but it’s a nice finishing touch to make things perfect For sure.
i use it and it shows up in my IO reg

 

[atanvarno]

Here are screenshots from real MacPro7,1 (sadly, I don't the exact config).

 

[atanvarno]

OpenCore's sample SSDT adds MCHC and SBUS devices.

What is this MCHC device doing, why it's added in the first place?
I can't find it anywhere in real MacPro's DSDT/SSDT.

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BTW, looking for explanation what MCHC is, I found this amazing repository which is translation from Daliansky's OC-Little chinese repo about Thinkpad hackintosh build.