[v6,5/7] of/platform: Pause/resume sync state during init and of_platform_populate()
diff mbox series

Message ID 20190720061647.234852-6-saravanak@google.com
State Superseded
Headers show
  • Solve postboot supplier cleanup and optimize probe ordering
Related show

Commit Message

Saravana Kannan July 20, 2019, 6:16 a.m. UTC
When all the top level devices are populated from DT during kernel
init, the supplier devices could be added and probed before the
consumer devices are added and linked to the suppliers. To avoid the
sync_state() callback from being called prematurely, pause the
sync_state() callbacks before populating the devices and resume them
at late_initcall_sync().

Similarly, when children devices are populated after kernel init using
of_platform_populate(), there could be supplier-consumer dependencies
between the children devices that are populated. To avoid the same
problem with sync_state() being called prematurely, pause and resume
sync_state() callbacks across of_platform_populate().

Signed-off-by: Saravana Kannan <saravanak@google.com>
 drivers/of/platform.c | 11 +++++++++++
 1 file changed, 11 insertions(+)

diff mbox series

diff --git a/drivers/of/platform.c b/drivers/of/platform.c
index 88a2086e26fa..d0c2f6443247 100644
--- a/drivers/of/platform.c
+++ b/drivers/of/platform.c
@@ -486,6 +486,7 @@  int of_platform_populate(struct device_node *root,
 	pr_debug("%s()\n", __func__);
 	pr_debug(" starting at: %pOF\n", root);
+	device_links_supplier_sync_state_pause();
 	for_each_child_of_node(root, child) {
 		rc = of_platform_bus_create(child, matches, lookup, parent, true);
 		if (rc) {
@@ -493,6 +494,8 @@  int of_platform_populate(struct device_node *root,
+	device_links_supplier_sync_state_resume();
 	of_node_set_flag(root, OF_POPULATED_BUS);
@@ -682,6 +685,7 @@  static int __init of_platform_default_populate_init(void)
 		return -ENODEV;
 	platform_bus_type.add_links = of_link_to_suppliers;
+	device_links_supplier_sync_state_pause();
 	 * Handle certain compatibles explicitly, since we don't want to create
 	 * platform_devices for every node in /reserved-memory with a
@@ -702,6 +706,13 @@  static int __init of_platform_default_populate_init(void)
 	return 0;
+static int __init of_platform_sync_state_init(void)
+	device_links_supplier_sync_state_resume();
+	return 0;
 int of_platform_device_destroy(struct device *dev, void *data)