[TRACKING] Controlling Power Direction for USB C

I know this is an old thread, but just adding some info:

There is a change in the 3.19 BIOS for 11th gen laptops:

Since I have a weird obsession with ACPI mutexes I took a look at this. BIOS 3.17 had no locking around ACPI → EC access for UCSI, which is bad.

BIOS 3.19 introduces two new mutexes called “UBSY” and “UBS0”. This doesn’t look like a good fix. It would be better to lock the existing mutex “ECMT”.

I tried fixing this on my machine by creating a new AML file in the initramfs, which overrides the BIOS AML. I think it behaved a bit better but it still doesn’t want to change source/sink for my Anker power thingy.

[edit: I also fixed the “version missing” problem in my replacement AML]

I can put some example code on github if anyone is interested.

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