On Fri, May 27, 2022 at 11:02 AM Sakari Ailus <sakari.ailus@xxxxxxxxxxxxxxx> wrote: > > Hi Rafael, > > On Thu, May 26, 2022 at 09:19:17PM +0200, Rafael J. Wysocki wrote: > > > +static int acpi_tie_nondev_subnodes(struct acpi_device_data *data) > > > +{ > > > + struct acpi_data_node *dn; > > > + > > > + list_for_each_entry(dn, &data->subnodes, sibling) { > > > + acpi_status status; > > > + int ret; > > > + > > > + status = acpi_attach_data(dn->handle, acpi_nondev_subnode_tag, dn); > > > + if (ACPI_FAILURE(status)) { > > > + acpi_handle_err(dn->handle, "Can't tag data node\n"); > > > + return 0; > > > + } > > > + > > > + ret = acpi_tie_nondev_subnodes(&dn->data); > > > + if (ret) > > > + return ret; > > > > Is it actually possible that this returns anything different from 0? > > acpi_attach_data() involves allocating memory and resolving a reference. > Both can fail. Yes, they can, but the value returned by acpi_attach_data() is effectively ignored above (except for printing the error message, which BTW could be "info" and provide more information). I don't see how acpi_tie_nondev_subnodes() can produce a nonzero return value.