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Merge remote-tracking branch 'wsa/i2c/fix-registration' into i2c/i2c-host

Browse Source 
Merge Johan Hovold's adapter registration fixes from Wolfram's
branch, addressing races, cleanup paths and resource management
issues.
This commit is contained in:
Andi Shyti
2026-06-09 14:08:00 +02:00
parent 7c9474bd4a 1640403fd3
commit 233644f6d4
1 changed files with 100 additions and 73 deletions
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173
drivers/i2c/i2c-core-base.c
View File

@@ -63,6 +63,7 @@
static DEFINE_MUTEX(core_lock);
static DEFINE_IDR(i2c_adapter_idr);
static void i2c_deregister_clients(struct i2c_adapter *adap);
static int i2c_detect(struct i2c_adapter *adapter, struct i2c_driver *driver);
static DEFINE_STATIC_KEY_FALSE(i2c_trace_msg_key);
@@ -1516,23 +1517,48 @@ int i2c_handle_smbus_host_notify(struct i2c_adapter *adap, unsigned short addr)
}
EXPORT_SYMBOL_GPL(i2c_handle_smbus_host_notify);
static int i2c_allocate_adapter_id(struct i2c_adapter *adap)
{
int id, start, end;
if (adap->nr == -1) {
start = __i2c_first_dynamic_bus_num;
end = 0;
} else {
start = adap->nr;
end = adap->nr + 1;
}
mutex_lock(&core_lock);
id = idr_alloc(&i2c_adapter_idr, NULL, start, end, GFP_KERNEL);
mutex_unlock(&core_lock);
if (id < 0) {
if (adap->nr != -1 && id == -ENOSPC)
id = -EBUSY;
pr_err("adapter '%s': failed to allocate id: %d\n", adap->name, id);
return id;
}
adap->nr = id;
return 0;
}
static int i2c_register_adapter(struct i2c_adapter *adap)
{
int res = -EINVAL;
int res;
/* Can't register until after driver model init */
if (WARN_ON(!is_registered)) {
res = -EAGAIN;
goto out_list;
}
if (WARN_ON(!is_registered))
return -EAGAIN;
/* Sanity checks */
if (WARN(!adap->name[0], "i2c adapter has no name"))
goto out_list;
return -EINVAL;
if (!adap->algo) {
pr_err("adapter '%s': no algo supplied!\n", adap->name);
goto out_list;
return -EINVAL;
}
if (!adap->lock_ops)
@@ -1553,14 +1579,25 @@ static int i2c_register_adapter(struct i2c_adapter *adap)
if (res) {
pr_err("adapter '%s': can't create Host Notify IRQs (%d)\n",
adap->name, res);
goto out_list;
return res;
}
dev_set_name(&adap->dev, "i2c-%d", adap->nr);
res = i2c_allocate_adapter_id(adap);
if (res)
goto err_remove_irq_domain;
res = dev_set_name(&adap->dev, "i2c-%d", adap->nr);
if (res)
goto err_free_id;
adap->dev.bus = &i2c_bus_type;
adap->dev.type = &i2c_adapter_type;
device_initialize(&adap->dev);
res = i2c_init_recovery(adap);
if (res == -EPROBE_DEFER)
goto err_put_adap;
/*
* This adapter can be used as a parent immediately after device_add(),
* setup runtime-pm (especially ignore-children) before hand.
@@ -1570,22 +1607,21 @@ static int i2c_register_adapter(struct i2c_adapter *adap)
pm_suspend_ignore_children(&adap->dev, true);
pm_runtime_enable(&adap->dev);
adap->debugfs = debugfs_create_dir(dev_name(&adap->dev), i2c_debugfs_root);
mutex_lock(&core_lock);
idr_replace(&i2c_adapter_idr, adap, adap->nr);
mutex_unlock(&core_lock);
res = device_add(&adap->dev);
if (res) {
pr_err("adapter '%s': can't register device (%d)\n", adap->name, res);
put_device(&adap->dev);
goto out_list;
goto err_replace_id;
}
adap->debugfs = debugfs_create_dir(dev_name(&adap->dev), i2c_debugfs_root);
res = i2c_setup_smbus_alert(adap);
if (res)
goto out_reg;
res = i2c_init_recovery(adap);
if (res == -EPROBE_DEFER)
goto out_reg;
goto err_deregister_clients;
dev_dbg(&adap->dev, "adapter [%s] registered\n", adap->name);
@@ -1604,38 +1640,29 @@ static int i2c_register_adapter(struct i2c_adapter *adap)
return 0;
out_reg:
err_deregister_clients:
i2c_deregister_clients(adap);
device_del(&adap->dev);
err_replace_id:
mutex_lock(&core_lock);
idr_replace(&i2c_adapter_idr, NULL, adap->nr);
mutex_unlock(&core_lock);
debugfs_remove_recursive(adap->debugfs);
pm_runtime_disable(&adap->dev);
err_put_adap:
init_completion(&adap->dev_released);
device_unregister(&adap->dev);
put_device(&adap->dev);
wait_for_completion(&adap->dev_released);
out_list:
err_free_id:
mutex_lock(&core_lock);
idr_remove(&i2c_adapter_idr, adap->nr);
mutex_unlock(&core_lock);
err_remove_irq_domain:
i2c_host_notify_irq_teardown(adap);
return res;
}
/**
* __i2c_add_numbered_adapter - i2c_add_numbered_adapter where nr is never -1
* @adap: the adapter to register (with adap->nr initialized)
* Context: can sleep
*
* See i2c_add_numbered_adapter() for details.
*/
static int __i2c_add_numbered_adapter(struct i2c_adapter *adap)
{
int id;
mutex_lock(&core_lock);
id = idr_alloc(&i2c_adapter_idr, adap, adap->nr, adap->nr + 1, GFP_KERNEL);
mutex_unlock(&core_lock);
if (WARN(id < 0, "couldn't get idr"))
return id == -ENOSPC ? -EBUSY : id;
return i2c_register_adapter(adap);
}
/**
* i2c_add_adapter - declare i2c adapter, use dynamic bus number
* @adapter: the adapter to add
@@ -1656,17 +1683,8 @@ int i2c_add_adapter(struct i2c_adapter *adapter)
int id;
id = of_alias_get_id(dev->of_node, "i2c");
if (id >= 0) {
adapter->nr = id;
return __i2c_add_numbered_adapter(adapter);
}
mutex_lock(&core_lock);
id = idr_alloc(&i2c_adapter_idr, adapter,
__i2c_first_dynamic_bus_num, 0, GFP_KERNEL);
mutex_unlock(&core_lock);
if (WARN(id < 0, "couldn't get idr"))
return id;
if (id < 0)
id = -1;
adapter->nr = id;
@@ -1702,7 +1720,7 @@ int i2c_add_numbered_adapter(struct i2c_adapter *adap)
if (adap->nr == -1) /* -1 means dynamically assign bus id */
return i2c_add_adapter(adap);
return __i2c_add_numbered_adapter(adap);
return i2c_register_adapter(adap);
}
EXPORT_SYMBOL_GPL(i2c_add_numbered_adapter);
@@ -1744,29 +1762,10 @@ static int __process_removed_adapter(struct device_driver *d, void *data)
return 0;
}
/**
* i2c_del_adapter - unregister I2C adapter
* @adap: the adapter being unregistered
* Context: can sleep
*
* This unregisters an I2C adapter which was previously registered
* by @i2c_add_adapter or @i2c_add_numbered_adapter.
*/
void i2c_del_adapter(struct i2c_adapter *adap)
static void i2c_deregister_clients(struct i2c_adapter *adap)
{
struct i2c_adapter *found;
struct i2c_client *client, *next;
/* First make sure that this adapter was ever added */
mutex_lock(&core_lock);
found = idr_find(&i2c_adapter_idr, adap->nr);
mutex_unlock(&core_lock);
if (found != adap) {
pr_debug("attempting to delete unregistered adapter [%s]\n", adap->name);
return;
}
i2c_acpi_remove_space_handler(adap);
/* Tell drivers about this removal */
mutex_lock(&core_lock);
bus_for_each_drv(&i2c_bus_type, NULL, adap,
@@ -1792,6 +1791,34 @@ void i2c_del_adapter(struct i2c_adapter *adap)
* them up properly, so we give them a chance to do that first. */
device_for_each_child(&adap->dev, NULL, __unregister_client);
device_for_each_child(&adap->dev, NULL, __unregister_dummy);
}
/**
* i2c_del_adapter - unregister I2C adapter
* @adap: the adapter being unregistered
* Context: can sleep
*
* This unregisters an I2C adapter which was previously registered
* by @i2c_add_adapter or @i2c_add_numbered_adapter.
*/
void i2c_del_adapter(struct i2c_adapter *adap)
{
struct i2c_adapter *found;
/* First make sure that this adapter was ever added */
mutex_lock(&core_lock);
found = idr_find(&i2c_adapter_idr, adap->nr);
if (found == adap)
idr_replace(&i2c_adapter_idr, NULL, adap->nr);
mutex_unlock(&core_lock);
if (found != adap) {
pr_debug("attempting to delete unregistered adapter [%s]\n", adap->name);
return;
}
i2c_acpi_remove_space_handler(adap);
i2c_deregister_clients(adap);
/* device name is gone after device_unregister */
dev_dbg(&adap->dev, "adapter [%s] unregistered\n", adap->name);