of/platform: Pause/resume sync state during init and of_platform_populate() (21871a99) · Commits · 戴 / test

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> Link: https://lore.kernel.org/r/20190731221721.187713-6-saravanak@google.com Signed-off-by:

Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/of/platform.c

+11 −0

Original line number	Diff line number	Diff line
		@@ -480,6 +480,7 @@ 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) {
		@@ -487,6 +488,8 @@ int of_platform_populate(struct device_node *root,
		break;
		}
		}
		device_links_supplier_sync_state_resume();

		of_node_set_flag(root, OF_POPULATED_BUS);

		of_node_put(root);
		@@ -683,6 +686,7 @@ 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
		@@ -703,6 +707,13 @@ static int __init of_platform_default_populate_init(void)
		return 0;
		}
		arch_initcall_sync(of_platform_default_populate_init);

		static int __init of_platform_sync_state_init(void)
		{
		device_links_supplier_sync_state_resume();
		return 0;
		}
		late_initcall_sync(of_platform_sync_state_init);
		#endif

		int of_platform_device_destroy(struct device dev, void data)

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