The adapters (de)registration are now protectd by using a dedicated
mutex instead of using global "core_lock" one. This allow multiple
(and recursive) (de)registration of several adapters (or i2c
multiplexers acting as i2c virtual adapters).
Signed-off-by: Rodolfo Giometti <giometti@xxxxxxxx>
---
drivers/i2c/i2c-core.c | 57 +++++++++++++++++++++++------------------------
1 files changed, 28 insertions(+), 29 deletions(-)
diff --git a/drivers/i2c/i2c-core.c b/drivers/i2c/i2c-core.c
index 5d3646f..4b088ef 100644
--- a/drivers/i2c/i2c-core.c
+++ b/drivers/i2c/i2c-core.c
@@ -40,6 +40,7 @@
static DEFINE_MUTEX(core_lock);
+static DEFINE_MUTEX(idr_adapter_lock);
static DEFINE_IDR(i2c_adapter_idr);
#define is_newstyle_driver(d) ((d)->probe || (d)->remove || (d)->detect)
@@ -438,7 +439,7 @@ static int i2c_do_add_adapter(struct device_driver *d, void *data)
static int i2c_register_adapter(struct i2c_adapter *adap)
{
- int res = 0, dummy;
+ int res, dummy;
/* Can't register until after driver model init */
if (unlikely(WARN_ON(!i2c_bus_type.p)))
@@ -448,8 +449,6 @@ static int i2c_register_adapter(struct i2c_adapter *adap)
mutex_init(&adap->clist_lock);
INIT_LIST_HEAD(&adap->clients);
- mutex_lock(&core_lock);
-
/* Add the adapter to the driver core.
* If the parent pointer is not set up,
* we add this adapter to the host bus.
@@ -463,8 +462,13 @@ static int i2c_register_adapter(struct i2c_adapter *adap)
adap->dev.release = &i2c_adapter_dev_release;
adap->dev.class = &i2c_adapter_class;
res = device_register(&adap->dev);
- if (res)
- goto out_list;
+ if (res) {
+ mutex_lock(&idr_adapter_lock);
+ idr_remove(&i2c_adapter_idr, adap->nr);
+ mutex_unlock(&idr_adapter_lock);
+
+ return res;
+ }
dev_dbg(&adap->dev, "adapter [%s] registered\n", adap->name);
@@ -476,13 +480,7 @@ static int i2c_register_adapter(struct i2c_adapter *adap)
dummy = bus_for_each_drv(&i2c_bus_type, NULL, adap,
i2c_do_add_adapter);
-out_unlock:
- mutex_unlock(&core_lock);
- return res;
-
-out_list:
- idr_remove(&i2c_adapter_idr, adap->nr);
- goto out_unlock;
+ return 0;
}
/**
@@ -506,11 +504,11 @@ retry:
if (idr_pre_get(&i2c_adapter_idr, GFP_KERNEL) == 0)
return -ENOMEM;
- mutex_lock(&core_lock);
+ mutex_lock(&idr_adapter_lock);
/* "above" here means "above or equal to", sigh */
res = idr_get_new_above(&i2c_adapter_idr, adapter,
__i2c_first_dynamic_bus_num, &id);
- mutex_unlock(&core_lock);
+ mutex_unlock(&idr_adapter_lock);
if (res < 0) {
if (res == -EAGAIN)
@@ -555,7 +553,7 @@ retry:
if (idr_pre_get(&i2c_adapter_idr, GFP_KERNEL) == 0)
return -ENOMEM;
- mutex_lock(&core_lock);
+ mutex_lock(&idr_adapter_lock);
/* "above" here means "above or equal to", sigh;
* we need the "equal to" result to force the result
*/
@@ -564,7 +562,7 @@ retry:
status = -EBUSY;
idr_remove(&i2c_adapter_idr, id);
}
- mutex_unlock(&core_lock);
+ mutex_unlock(&idr_adapter_lock);
if (status == -EAGAIN)
goto retry;
@@ -612,19 +610,25 @@ static int i2c_do_del_adapter(struct device_driver *d, void *data)
*/
int i2c_del_adapter(struct i2c_adapter *adap)
{
+ struct i2c_adapter *ptr;
struct i2c_client *client, *_n;
- int res = 0, dummy;
+ int dummy;
- mutex_lock(&core_lock);
+ mutex_lock(&idr_adapter_lock);
/* First make sure that this adapter was ever added */
- if (idr_find(&i2c_adapter_idr, adap->nr) != adap) {
+ ptr = idr_find(&i2c_adapter_idr, adap->nr);
+ if (ptr != adap) {
pr_debug("i2c-core: attempting to delete unregistered "
"adapter [%s]\n", adap->name);
- res = -EINVAL;
- goto out_unlock;
+ mutex_unlock(&idr_adapter_lock);
+ return -EINVAL;
}
+ /* ... then remove adapter ID */
+ idr_remove(&i2c_adapter_idr, adap->nr);
+ mutex_unlock(&idr_adapter_lock);
+
/* Tell drivers about this removal */
dummy = bus_for_each_drv(&i2c_bus_type, NULL, adap,
i2c_do_del_adapter);
@@ -655,18 +659,13 @@ int i2c_del_adapter(struct i2c_adapter *adap)
/* wait for sysfs to drop all references */
wait_for_completion(&adap->dev_released);
- /* free bus id */
- idr_remove(&i2c_adapter_idr, adap->nr);
-
dev_dbg(&adap->dev, "adapter [%s] unregistered\n", adap->name);
/* Clear the device structure in case this adapter is ever going to be
added again */
memset(&adap->dev, 0, sizeof(adap->dev));
- out_unlock:
- mutex_unlock(&core_lock);
- return res;
+ return 0;
}
EXPORT_SYMBOL(i2c_del_adapter);
@@ -1497,12 +1496,12 @@ struct i2c_adapter* i2c_get_adapter(int id)
{
struct i2c_adapter *adapter;
- mutex_lock(&core_lock);
+ mutex_lock(&idr_adapter_lock);
adapter = (struct i2c_adapter *)idr_find(&i2c_adapter_idr, id);
if (adapter && !try_module_get(adapter->owner))
adapter = NULL;
- mutex_unlock(&core_lock);
+ mutex_unlock(&idr_adapter_lock);
return adapter;
}
EXPORT_SYMBOL(i2c_get_adapter);
--
1.5.6.3
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