6.1-stable review patch. If anyone has any objections, please let me know. ------------------ From: Saravana Kannan <saravanak@xxxxxxxxxx> commit 4a032827daa89350365166b19d14d82fe8219128 upstream. The driver core now: - Has the parent device of a supplier pick up the consumers if the supplier never has a device created for it. - Ignores a supplier if the supplier has no parent device and will never be probed by a driver And already prevents creating a device link with the consumer as a supplier of a parent. So, we no longer need to find the "compatible" node of the supplier or do any other checks in of_link_to_phandle(). We simply need to make sure that the supplier is available in DT. Signed-off-by: Saravana Kannan <saravanak@xxxxxxxxxx> Tested-by: Colin Foster <colin.foster@xxxxxxxxxxxxxxxx> Tested-by: Sudeep Holla <sudeep.holla@xxxxxxx> Tested-by: Douglas Anderson <dianders@xxxxxxxxxxxx> Tested-by: Geert Uytterhoeven <geert+renesas@xxxxxxxxx> Tested-by: Luca Weiss <luca.weiss@xxxxxxxxxxxxx> # qcom/sm7225-fairphone-fp4 Link: https://lore.kernel.org/r/20230207014207.1678715-10-saravanak@xxxxxxxxxx Fixes: eaf9b5612a47 ("driver core: fw_devlink: Don't purge child fwnode's consumer links") Signed-off-by: Adam Ford <aford173@xxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- drivers/of/property.c | 84 +++++++------------------------------------------- 1 file changed, 13 insertions(+), 71 deletions(-) --- a/drivers/of/property.c +++ b/drivers/of/property.c @@ -1062,20 +1062,6 @@ of_fwnode_device_get_match_data(const st return of_device_get_match_data(dev); } -static bool of_is_ancestor_of(struct device_node *test_ancestor, - struct device_node *child) -{ - of_node_get(child); - while (child) { - if (child == test_ancestor) { - of_node_put(child); - return true; - } - child = of_get_next_parent(child); - } - return false; -} - static struct device_node *of_get_compat_node(struct device_node *np) { of_node_get(np); @@ -1106,71 +1092,27 @@ static struct device_node *of_get_compat return node; } -/** - * of_link_to_phandle - Add fwnode link to supplier from supplier phandle - * @con_np: consumer device tree node - * @sup_np: supplier device tree node - * - * Given a phandle to a supplier device tree node (@sup_np), this function - * finds the device that owns the supplier device tree node and creates a - * device link from @dev consumer device to the supplier device. This function - * doesn't create device links for invalid scenarios such as trying to create a - * link with a parent device as the consumer of its child device. In such - * cases, it returns an error. - * - * Returns: - * - 0 if fwnode link successfully created to supplier - * - -EINVAL if the supplier link is invalid and should not be created - * - -ENODEV if struct device will never be create for supplier - */ -static int of_link_to_phandle(struct device_node *con_np, +static void of_link_to_phandle(struct device_node *con_np, struct device_node *sup_np) { - struct device *sup_dev; - struct device_node *tmp_np = sup_np; + struct device_node *tmp_np = of_node_get(sup_np); - /* - * Find the device node that contains the supplier phandle. It may be - * @sup_np or it may be an ancestor of @sup_np. - */ - sup_np = of_get_compat_node(sup_np); - if (!sup_np) { - pr_debug("Not linking %pOFP to %pOFP - No device\n", - con_np, tmp_np); - return -ENODEV; - } + /* Check that sup_np and its ancestors are available. */ + while (tmp_np) { + if (of_fwnode_handle(tmp_np)->dev) { + of_node_put(tmp_np); + break; + } - /* - * Don't allow linking a device node as a consumer of one of its - * descendant nodes. By definition, a child node can't be a functional - * dependency for the parent node. - */ - if (of_is_ancestor_of(con_np, sup_np)) { - pr_debug("Not linking %pOFP to %pOFP - is descendant\n", - con_np, sup_np); - of_node_put(sup_np); - return -EINVAL; - } + if (!of_device_is_available(tmp_np)) { + of_node_put(tmp_np); + return; + } - /* - * Don't create links to "early devices" that won't have struct devices - * created for them. - */ - sup_dev = get_dev_from_fwnode(&sup_np->fwnode); - if (!sup_dev && - (of_node_check_flag(sup_np, OF_POPULATED) || - sup_np->fwnode.flags & FWNODE_FLAG_NOT_DEVICE)) { - pr_debug("Not linking %pOFP to %pOFP - No struct device\n", - con_np, sup_np); - of_node_put(sup_np); - return -ENODEV; + tmp_np = of_get_next_parent(tmp_np); } - put_device(sup_dev); fwnode_link_add(of_fwnode_handle(con_np), of_fwnode_handle(sup_np)); - of_node_put(sup_np); - - return 0; } /**
