i2c: Limit core locking to the necessary sections (35fc37f8) · Commits · 戴 / test

drivers/i2c/i2c-core.c

+28 −23

Original line number	Diff line number	Diff line
		@@ -38,6 +38,9 @@
		#include "i2c-core.h"


		/* core_lock protects i2c_adapter_idr, and guarantees
		that device detection, deletion of detected devices, and attach_adapter
		and detach_adapter calls are serialized */
		static DEFINE_MUTEX(core_lock);
		static DEFINE_IDR(i2c_adapter_idr);

		@@ -418,13 +421,13 @@ static int i2c_register_adapter(struct i2c_adapter *adap)
		int res = 0, dummy;

		/* Can't register until after driver model init */
		if (unlikely(WARN_ON(!i2c_bus_type.p)))
		return -EAGAIN;
		if (unlikely(WARN_ON(!i2c_bus_type.p))) {
		res = -EAGAIN;
		goto out_list;
		}

		mutex_init(&adap->bus_lock);

		mutex_lock(&core_lock);

		/* Set default timeout to 1 second if not already set */
		if (adap->timeout == 0)
		adap->timeout = HZ;
		@@ -443,16 +446,18 @@ static int i2c_register_adapter(struct i2c_adapter *adap)
		i2c_scan_static_board_info(adap);

		/* Notify drivers */
		mutex_lock(&core_lock);
		dummy = bus_for_each_drv(&i2c_bus_type, NULL, adap,
		i2c_do_add_adapter);

		out_unlock:
		mutex_unlock(&core_lock);
		return res;

		return 0;

		out_list:
		mutex_lock(&core_lock);
		idr_remove(&i2c_adapter_idr, adap->nr);
		goto out_unlock;
		mutex_unlock(&core_lock);
		return res;
		}

		/**
		@@ -590,22 +595,25 @@ static int __unregister_client(struct device dev, void dummy)
		int i2c_del_adapter(struct i2c_adapter *adap)
		{
		int res = 0;

		mutex_lock(&core_lock);
		struct i2c_adapter *found;

		/* First make sure that this adapter was ever added */
		if (idr_find(&i2c_adapter_idr, adap->nr) != adap) {
		mutex_lock(&core_lock);
		found = idr_find(&i2c_adapter_idr, adap->nr);
		mutex_unlock(&core_lock);
		if (found != adap) {
		pr_debug("i2c-core: attempting to delete unregistered "
		"adapter [%s]\n", adap->name);
		res = -EINVAL;
		goto out_unlock;
		return -EINVAL;
		}

		/* Tell drivers about this removal */
		mutex_lock(&core_lock);
		res = bus_for_each_drv(&i2c_bus_type, NULL, adap,
		i2c_do_del_adapter);
		mutex_unlock(&core_lock);
		if (res)
		goto out_unlock;
		return res;

		/* Detach any active clients. This can't fail, thus we do not
		checking the returned value. */
		@@ -619,7 +627,9 @@ int i2c_del_adapter(struct i2c_adapter *adap)
		wait_for_completion(&adap->dev_released);

		/* free bus id */
		mutex_lock(&core_lock);
		idr_remove(&i2c_adapter_idr, adap->nr);
		mutex_unlock(&core_lock);

		dev_dbg(&adap->dev, "adapter [%s] unregistered\n", adap->name);

		@@ -627,9 +637,7 @@ int i2c_del_adapter(struct i2c_adapter *adap)
		added again */
		memset(&adap->dev, 0, sizeof(adap->dev));

		out_unlock:
		mutex_unlock(&core_lock);
		return res;
		return 0;
		}
		EXPORT_SYMBOL(i2c_del_adapter);

		@@ -674,16 +682,15 @@ int i2c_register_driver(struct module owner, struct i2c_driver driver)
		if (res)
		return res;

		mutex_lock(&core_lock);

		pr_debug("i2c-core: driver [%s] registered\n", driver->driver.name);

		INIT_LIST_HEAD(&driver->clients);
		/* Walk the adapters that are already present */
		mutex_lock(&core_lock);
		class_for_each_device(&i2c_adapter_class, NULL, driver,
		__attach_adapter);

		mutex_unlock(&core_lock);

		return 0;
		}
		EXPORT_SYMBOL(i2c_register_driver);
		@@ -721,14 +728,12 @@ static int __detach_adapter(struct device dev, void data)
		void i2c_del_driver(struct i2c_driver *driver)
		{
		mutex_lock(&core_lock);

		class_for_each_device(&i2c_adapter_class, NULL, driver,
		__detach_adapter);
		mutex_unlock(&core_lock);

		driver_unregister(&driver->driver);
		pr_debug("i2c-core: driver [%s] unregistered\n", driver->driver.name);

		mutex_unlock(&core_lock);
		}
		EXPORT_SYMBOL(i2c_del_driver);

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