Matt Delco has posted comments on this change. ( https://review.coreboot.org/28073 )
Change subject: mainboard/google/nocturne: turn off cams in D3 ......................................................................
Patch Set 1:
Again I don't think that statement is true, a value in _PR3 does not mean to keep device power in D3Hot. For your reference, the following code https://chromium.googlesource.com/chromiumos/third_party/kernel/+/stabilize-... did explain that.
Is there a particular place that is supposed to illustrate this? It looks to me like acpi_power_transition() calls acpi_power_on_list() on items in the list for the new power state and calls acpi_power_off_list() on items in old list. So, having a _PR3 keeps the power on in D3Hot.
May I know what kind of problem you are facing now? The steps in _OFF had not been executed?
The device (or at least the privacy light) never turns off in Windows. If no driver is installed for the camera then the light stays on. If I install a driver for the device then the light stays on. If I install a driver and modify ACPI then the light does turn off. I might be able to convince the light to go off by having the driver try harder to claim support for D3cold but this is going beyond the Intel reference examples and again I don't see any other MIPI camera outside of coreboot that uses _PR3.