On Fri, Feb 28, 2014 at 3:18 PM, Dan Williams <dan.j.williams@xxxxxxxxx> wrote: > ACPI identifies peer ports by setting their 'group_token' and > 'group_position' _PLD data to the same value. If a platform has tier > mismatch [1] , ACPI can override the default (USB3 defined) peer port > association for internal hubs. External hubs follow the default peer > association scheme. > > Location data is cached as an opaque cookie in usb_port_location data. > > Note that we only consider the group_token and group_position attributes > from the _PLD data as ACPI specifies that group_token is a unique > identifier. > > When we find port location data for a port then we assume that the > firmware will also describe its peer port. This allows the > implementation to only ever set the peer once. However, once a peer is > set via firmware data we need to recursively set the default peer for > port below that port in the hierarchy. Last sentence should have been deleted... -- To unsubscribe from this list: send the line "unsubscribe linux-usb" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
