On Tue, Jun 28, 2022 at 1:54 PM Michael Walle <michael@xxxxxxxx> wrote: > > Am 2022-06-28 13:10, schrieb Andy Shevchenko: > > On Mon, Jun 27, 2022 at 02:49:51PM +0200, Michael Walle wrote: > >> Hi, > >> > >> I tired to iterate over all child nodes, regardless if they are > >> available > >> or not. Now there is that handy fwnode_for_each_child_node() (and the > >> fwnode_for_each_available_child_node()). The only thing is the OF > >> backend > >> already skips disabled nodes [1], making fwnode_for_each_child_node() > >> and > >> fwnode_for_each_available_child_node() behave the same with the OF > >> backend. > >> > >> Doesn't seem to be noticed by anyone for now. I'm not sure how to fix > >> that > >> one. fwnode_for_each_child_node() and also > >> fwnode_get_next_child_node() are > >> used by a handful of drivers. I've looked at some, but couldn't decide > >> whether they really want to iterate over all child nodes or just the > >> enabled > >> ones. > >> > >> Any thoughts? > > > > It was discussed at least twice this year (in regard to some new IIO > > drivers) > > and Rob told that iterating over disabled (not available) nodes in OF > > kinda > > legacy/design mistake. That's why device_for_each_child_node() goes > > only > > over available nodes only. > > Mh, but then the fwnode_for_each_child_node() is very misleading, esp. > with the presence of fwnode_for_each_available_child_node(). > > > So, why do you need to iterate over disabled ones? > > I was trying to fix the lan966x driver [1] which doesn't work if there > are disabled nodes in between. Can you elaborate what's wrong now in the behaviour of the driver? In the code it uses twice the _available variant. > My steps would have been: > (1) change fwnode_for_each_available_child_node() to > fwnode_for_each_child_node(), maybe with a fixes tag, as it's > easy to backport > (2) introduce new compatibles and deduce the number of ports > according to the compatible string and not by counting > the child nodes. > (3) keep the old behavior for the legacy compatible and mark it > as deprecated in the binding > (4) move the device tree over to the new compatible string > [1] > https://elixir.bootlin.com/linux/v5.19-rc4/source/drivers/net/ethernet/microchip/lan966x/lan966x_main.c -- With Best Regards, Andy Shevchenko
