usb: typec: tcpm: Don't block probing of consumers of "connector" nodes

fw_devlink expects DT device nodes with "compatible" property to have
struct devices created for them. Since the connector node might not be
populated as a device, mark it as such so that fw_devlink knows not to
wait on this fwnode being populated as a struct device.

Without this patch, USB functionality can be broken on some boards.

Fixes: f7514a6 ("of: property: fw_devlink: Add support for remote-endpoint")
Reported-by: John Stultz <john.stultz@linaro.org>
Tested-by: John Stultz <john.stultz@linaro.org>
Signed-off-by: Saravana Kannan <saravanak@google.com>
Link: https://lore.kernel.org/r/20210506004423.345199-1-saravanak@google.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Author: Saravana Kannan

drivers/base/core.c

@@ -150,7 +150,7 @@ void fwnode_links_purge(struct fwnode_handle *fwnode)
 	fwnode_links_purge_consumers(fwnode);
 }
 
-static void fw_devlink_purge_absent_suppliers(struct fwnode_handle *fwnode)
+void fw_devlink_purge_absent_suppliers(struct fwnode_handle *fwnode)
 {
 	struct fwnode_handle *child;
 
@@ -164,6 +164,7 @@ static void fw_devlink_purge_absent_suppliers(struct fwnode_handle *fwnode)
 	fwnode_for_each_available_child_node(fwnode, child)
 		fw_devlink_purge_absent_suppliers(child);
 }
+EXPORT_SYMBOL_GPL(fw_devlink_purge_absent_suppliers);
 
 #ifdef CONFIG_SRCU
 static DEFINE_MUTEX(device_links_lock);

drivers/usb/typec/tcpm/tcpm.c

@@ -5754,6 +5754,15 @@ static int tcpm_fw_get_caps(struct tcpm_port *port,
 	if (!fwnode)
 		return -EINVAL;
 
+	/*
+	 * This fwnode has a "compatible" property, but is never populated as a
+	 * struct device. Instead we simply parse it to read the properties.
+	 * This it breaks fw_devlink=on. To maintain backward compatibility
+	 * with existing DT files, we work around this by deleting any
+	 * fwnode_links to/from this fwnode.
+	 */
+	fw_devlink_purge_absent_suppliers(fwnode);
+
 	/* USB data support is optional */
 	ret = fwnode_property_read_string(fwnode, "data-role", &cap_str);
 	if (ret == 0) {

include/linux/fwnode.h

@@ -187,5 +187,6 @@ extern u32 fw_devlink_get_flags(void);
 extern bool fw_devlink_is_strict(void);
 int fwnode_link_add(struct fwnode_handle *con, struct fwnode_handle *sup);
 void fwnode_links_purge(struct fwnode_handle *fwnode);
+void fw_devlink_purge_absent_suppliers(struct fwnode_handle *fwnode);
 
 #endif