On Mon, Apr 10, 2017 at 12:59:36PM +0300, Sakari Ailus wrote: > Hi Mika and Laurent, > > On 04/10/17 12:21, Mika Westerberg wrote: > > On Sat, Apr 08, 2017 at 01:55:15AM +0300, Sakari Ailus wrote: > >>> My ACPI knowledge is limited, but don't ACPI nodes have 4 character names that > >>> can be combined in a string to create a full path ? > >> > >> There is something, yes, but the ACPI framework currently has no such > >> functionality. I believe it could be implemented though. Cc Mika. > > > > All ACPI node names are 32-bit integers and those are combined to form a > > path, like \_SB.PCI0.I2C0 and so on. A single ACPI node name cannot be > > larger than 4 chars, though. > > On OF, each node has a full_node string attached to it. You could > produce a similar string on ACPI, it is not currently done. Adding such > a string to each fwnode would require some extra memory as well. I > wonder if that could be a Kconfig option. > > It would help debugging though. > > Providing this information to the user space has been proposed as well: > Devicetree spec defines the syntax for such strings. The user can use > that information for recognising a particular device in the system. > > The ACPI spec does, too, but it is limited to ACPI nodes and does not > address hierarchical data extensions. We'd define the syntax for those > ourselves. > > Mika: what do you think? There is a function acpi_get_name() which you can use to extract the full name of the node. Why not investigate how to use that instead of duplicating the name in an ACPI node.
