On Fri, Feb 11, 2022 at 3:30 AM Won Chung <wonchung@xxxxxxxxxx> wrote: > > When ACPI table includes _PLD fields for a device, create a new > directory (pld) in sysfs to share _PLD fields. This version of the patch loos better to me, but I'm not sure if it goes into the right direction overall. > Currently without PLD information, when there are multiple of same > devices, it is hard to distinguish which device corresponds to which > physical device in which location. For example, when there are two Type > C connectors, it is hard to find out which connector corresponds to the > Type C port on the left panel versus the Type C port on the right panel. So I think that this is your primary use case and I'm wondering if this is the best way to address it. Namely, by exposing _PLD information under the ACPI device object, you'll make user space wanting to use that information depend on this interface, but the problem is not ACPI-specific (inevitably, it will appear on systems using DT, sooner or later) and making the user space interface related to it depend on ACPI doesn't look like a perfect choice. IOW, why don't you create a proper ABI for this in the Type C subsystem and expose the information needed by user space in a generic way that can be based on the _PLD information on systems with ACPI?
