PCI/pwrctrl: Create pwrctrl devices only for PCI device nodes

A PCI host bridge node can have non-PCI child nodes (OPP tables, USB
hub, etc.) as well as PCI device child nodes.

Ensure that pwrctrl devices are only created for PCI device nodes by
checking for the 'pci' prefix in the compatible property.

Fixes: 4c41324 ("PCI/pwrctrl: Add APIs to create, destroy pwrctrl devices")
Reported-by: Bjorn Andersson <[email protected]>
Closes: https://lore.kernel.org/all/[email protected]
Signed-off-by: Manivannan Sadhasivam <[email protected]>
Signed-off-by: Bjorn Helgaas <[email protected]>
Link: https://patch.msgid.link/[email protected]

Author: Mani-Sadhasivam

drivers/pci/pwrctrl/core.c

@@ -272,16 +272,23 @@ EXPORT_SYMBOL_GPL(pci_pwrctrl_power_on_devices);
  * Check whether the pwrctrl device really needs to be created or not. The
  * pwrctrl device will only be created if the node satisfies below requirements:
  *
- * 1. Presence of compatible property to match against the pwrctrl driver (AND)
+ * 1. Presence of compatible property with "pci" prefix to match against the
+ *    pwrctrl driver (AND)
  * 2. At least one of the power supplies defined in the devicetree node of the
  *    device (OR) in the remote endpoint parent node to indicate pwrctrl
  *    requirement.
  */
 static bool pci_pwrctrl_is_required(struct device_node *np)
 {
 	struct device_node *endpoint;
+	const char *compat;
+	int ret;
+
+	ret = of_property_read_string(np, "compatible", &compat);
+	if (ret < 0)
+		return false;
 
-	if (!of_property_present(np, "compatible"))
+	if (!strstarts(compat, "pci"))
 		return false;
 
 	if (of_pci_supply_present(np))