On Wed, Apr 12, 2023 at 04:15:20PM +0300, Andy Shevchenko wrote:
> Propagate firmware node by using a specific API call, i.e. device_set_node().
Can you add a line or two about *why* we should do this, e.g., is this
headed toward some goal? Is it a simplification that's 100%
equivalent (doesn't seem so, see below)?
Seems like there's an underlying long-term effort to unify things from
OF and ACPI, which seems like a good thing, but at the moment it's a
little confusing to follow. For instance pci_set_of_node() seems like
it ought to be sort of analogous to pci_set_acpi_fwnode(), but they
look nothing alike.
> Signed-off-by: Andy Shevchenko <andriy.shevchenko@xxxxxxxxxxxxxxx>
> ---
> drivers/pci/of.c | 19 +++++++------------
> 1 file changed, 7 insertions(+), 12 deletions(-)
>
> diff --git a/drivers/pci/of.c b/drivers/pci/of.c
> index 196834ed44fe..4bba00dfbfc5 100644
> --- a/drivers/pci/of.c
> +++ b/drivers/pci/of.c
> @@ -18,19 +18,18 @@
> #ifdef CONFIG_PCI
> void pci_set_of_node(struct pci_dev *dev)
> {
> + struct device_node *node;
> +
> if (!dev->bus->dev.of_node)
> return;
> - dev->dev.of_node = of_pci_find_child_device(dev->bus->dev.of_node,
> - dev->devfn);
> - if (dev->dev.of_node)
> - dev->dev.fwnode = &dev->dev.of_node->fwnode;
> + node = of_pci_find_child_device(dev->bus->dev.of_node, dev->devfn);
> + device_set_node(&dev->dev, of_fwnode_handle(node));
This doesn't seem 100% equivalent. If of_pci_find_child_device()
returns NULL, the previous code doesn't set dev->dev.fwnode, but the
new code does.
> }
>
> void pci_release_of_node(struct pci_dev *dev)
> {
> of_node_put(dev->dev.of_node);
> - dev->dev.of_node = NULL;
> - dev->dev.fwnode = NULL;
> + device_set_node(&dev->dev, NULL);
> }
>
> void pci_set_bus_of_node(struct pci_bus *bus)
> @@ -45,17 +44,13 @@ void pci_set_bus_of_node(struct pci_bus *bus)
> bus->self->external_facing = true;
> }
>
> - bus->dev.of_node = node;
> -
> - if (bus->dev.of_node)
> - bus->dev.fwnode = &bus->dev.of_node->fwnode;
> + device_set_node(&bus->dev, of_fwnode_handle(node));
> }
>
> void pci_release_bus_of_node(struct pci_bus *bus)
> {
> of_node_put(bus->dev.of_node);
> - bus->dev.of_node = NULL;
> - bus->dev.fwnode = NULL;
> + device_set_node(&bus->dev, NULL);
> }
>
> struct device_node * __weak pcibios_get_phb_of_node(struct pci_bus *bus)
> --
> 2.40.0.1.gaa8946217a0b
>
