On Fri, Oct 29, 2021 at 4:38 AM Mark Rutland <mark.rutland@xxxxxxx> wrote: > > Hi Rob, > > On Thu, Oct 28, 2021 at 01:33:55PM -0500, Rob Herring wrote: > > Use of of_scan_flat_dt() function predates libfdt and is discouraged as > > libfdt provides a nicer set of APIs. Rework dt_scan_depth1_nodes to use > > libfdt calls directly. Rather than searching for any node not /chosen or > > /hypervisor, let's just check for something always required which is the > > arch timer. > > The reason for checking for /chosen and /hypervisor specifically was > that we specifically permit a "stub" DT which only contains those nodes > and nothing more. This is also mentioned in the comment block in > acpi_boot_table_init(). There will be a compatibility problem if another node is ever added to the stub. > I'm not keen on this change because it opens the door for people to > place arbitrary things in the DT as long as they don't add a timer node, > and I'd prefer that we continue to check for /chosen and /hypervisor > specifically. How would one use that? The DT is never unflattened. I guess early_init_dt_scan() could find something. > Can we re-implement the existing logic using libfdt calls? e.g. using > fdt_for_each_subnode() on the root node? Sure. Rob
