On 2015/11/24 7:32, Lukas Wunner wrote: > Hi Robert, > > On Mon, Nov 23, 2015 at 10:22:27PM +0000, Moore, Robert wrote: >>>> acpi_dev_present >> Do you really want to be walking the ACPICA namespace for every call? > That's what the drivers currently do. Typically this is called only once > on initialization by the driver's ->probe callback. > > What did you have in mind instead, cache the result? Or store the HIDs > in the namespace in a hash that can be queried faster? Will those drivers be loaded before the acpi namespace is scanned? if not, I think those IDs already cached, in acpi_init_device_object(), INIT_LIST_HEAD(&device->pnp.ids); ... acpi_set_pnp_ids(handle, &device->pnp, type); please see API acpi_device_hid(), so I think you can introduce a API with acpi_device and HID passed as arguments in scan.c Thanks Hanjun -- To unsubscribe from this list: send the line "unsubscribe linux-acpi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html