[PATCH 3/8] deep-probe: skip on-demand platform dev creation for nodes without compatible

[Ahmad Fatoum]

of_device_create_on_demand won't create a new device if the device tree
node already has a device associated. What it will do however, is to
create devices for all parent nodes in the device tree if they don't
already exist. This is unnecessary and clutters the device list
with nodes that won't ever be matched as they lack a compatible anyway.
For example a reference to scmi_reg11 in below snippet:

  &{scmi/protocol at 17} {
      reg = <0x17>;
      regulators {
          #address-cells = <0x1>;
          #size-cells = <0x0>;
          scmi_reg11: regulator at 0 {
              reg = <0x0>;
              regulator-name = "reg11";
          };
      };
  };

will result in creation of a device for the regulators node that serves
no purpose whatsoever:

  `-- firmware.of
     `-- firmware:scmi.of
        `-- scmi_dev0
           `-- firmware:scmi:protocol at 17:regulators.of

Avoid this by creating devices on demand only if they have a compatible.

Signed-off-by: Ahmad Fatoum <a.fatoum at pengutronix.de>
---
 drivers/of/platform.c | 8 +++++---
 1 file changed, 5 insertions(+), 3 deletions(-)

diff --git a/drivers/of/platform.c b/drivers/of/platform.c
index 9e592d567cae..9ba4438812c1 100644
--- a/drivers/of/platform.c
+++ b/drivers/of/platform.c
@@ -442,9 +442,6 @@ static struct device *of_device_create_on_demand(struct device_node *np)
 	if (!np->dev && parent->dev)
 		device_rescan(parent->dev);
 
-	if (!np->dev)
-		pr_debug("Creating device for %pOF\n", np);
-
 	/* Create all parent devices needed for the requested device */
 	parent_dev = parent->dev ? : of_device_create_on_demand(parent);
 	if (IS_ERR(parent_dev))
@@ -458,6 +455,11 @@ static struct device *of_device_create_on_demand(struct device_node *np)
 	if (np->dev)
 		return np->dev;
 
+	if (!of_property_present(np, "compatible"))
+		return NULL;
+
+	pr_debug("Creating device for %pOF\n", np);
+
 	if (of_device_is_compatible(np, "arm,primecell"))
 		dev = of_amba_device_create(np);
 	else
-- 
2.39.2