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path: root/drivers/base/bus.c
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Diffstat (limited to 'drivers/base/bus.c')
-rw-r--r--drivers/base/bus.c133
1 files changed, 79 insertions, 54 deletions
diff --git a/drivers/base/bus.c b/drivers/base/bus.c
index 2e954d0..12173d1 100644
--- a/drivers/base/bus.c
+++ b/drivers/base/bus.c
@@ -371,12 +371,20 @@ int bus_add_device(struct device * dev)
if (bus) {
pr_debug("bus %s: add device %s\n", bus->name, dev->bus_id);
error = device_add_attrs(bus, dev);
- if (!error) {
- sysfs_create_link(&bus->devices.kobj, &dev->kobj, dev->bus_id);
- sysfs_create_link(&dev->kobj, &dev->bus->subsys.kset.kobj, "subsystem");
- sysfs_create_link(&dev->kobj, &dev->bus->subsys.kset.kobj, "bus");
- }
+ if (error)
+ goto out;
+ error = sysfs_create_link(&bus->devices.kobj,
+ &dev->kobj, dev->bus_id);
+ if (error)
+ goto out;
+ error = sysfs_create_link(&dev->kobj,
+ &dev->bus->subsys.kset.kobj, "subsystem");
+ if (error)
+ goto out;
+ error = sysfs_create_link(&dev->kobj,
+ &dev->bus->subsys.kset.kobj, "bus");
}
+out:
return error;
}
@@ -384,16 +392,24 @@ int bus_add_device(struct device * dev)
* bus_attach_device - add device to bus
* @dev: device tried to attach to a driver
*
+ * - Add device to bus's list of devices.
* - Try to attach to driver.
*/
-void bus_attach_device(struct device * dev)
+int bus_attach_device(struct device * dev)
{
- struct bus_type * bus = dev->bus;
+ struct bus_type *bus = dev->bus;
+ int ret = 0;
if (bus) {
- device_attach(dev);
- klist_add_tail(&dev->knode_bus, &bus->klist_devices);
+ dev->is_registered = 1;
+ ret = device_attach(dev);
+ if (ret >= 0) {
+ klist_add_tail(&dev->knode_bus, &bus->klist_devices);
+ ret = 0;
+ } else
+ dev->is_registered = 0;
}
+ return ret;
}
/**
@@ -412,7 +428,8 @@ void bus_remove_device(struct device * dev)
sysfs_remove_link(&dev->kobj, "bus");
sysfs_remove_link(&dev->bus->devices.kobj, dev->bus_id);
device_remove_attrs(dev->bus, dev);
- klist_remove(&dev->knode_bus);
+ dev->is_registered = 0;
+ klist_del(&dev->knode_bus);
pr_debug("bus %s: remove device %s\n", dev->bus->name, dev->bus_id);
device_release_driver(dev);
put_bus(dev->bus);
@@ -455,10 +472,17 @@ static void driver_remove_attrs(struct bus_type * bus, struct device_driver * dr
* Thanks to drivers making their tables __devinit, we can't allow manual
* bind and unbind from userspace unless CONFIG_HOTPLUG is enabled.
*/
-static void add_bind_files(struct device_driver *drv)
+static int __must_check add_bind_files(struct device_driver *drv)
{
- driver_create_file(drv, &driver_attr_unbind);
- driver_create_file(drv, &driver_attr_bind);
+ int ret;
+
+ ret = driver_create_file(drv, &driver_attr_unbind);
+ if (ret == 0) {
+ ret = driver_create_file(drv, &driver_attr_bind);
+ if (ret)
+ driver_remove_file(drv, &driver_attr_unbind);
+ }
+ return ret;
}
static void remove_bind_files(struct device_driver *drv)
@@ -467,7 +491,7 @@ static void remove_bind_files(struct device_driver *drv)
driver_remove_file(drv, &driver_attr_unbind);
}
#else
-static inline void add_bind_files(struct device_driver *drv) {}
+static inline int add_bind_files(struct device_driver *drv) { return 0; }
static inline void remove_bind_files(struct device_driver *drv) {}
#endif
@@ -476,7 +500,7 @@ static inline void remove_bind_files(struct device_driver *drv) {}
* @drv: driver.
*
*/
-int bus_add_driver(struct device_driver * drv)
+int bus_add_driver(struct device_driver *drv)
{
struct bus_type * bus = get_bus(drv->bus);
int error = 0;
@@ -484,27 +508,39 @@ int bus_add_driver(struct device_driver * drv)
if (bus) {
pr_debug("bus %s: add driver %s\n", bus->name, drv->name);
error = kobject_set_name(&drv->kobj, "%s", drv->name);
- if (error) {
- put_bus(bus);
- return error;
- }
+ if (error)
+ goto out_put_bus;
drv->kobj.kset = &bus->drivers;
- if ((error = kobject_register(&drv->kobj))) {
- put_bus(bus);
- return error;
- }
+ if ((error = kobject_register(&drv->kobj)))
+ goto out_put_bus;
- driver_attach(drv);
+ error = driver_attach(drv);
+ if (error)
+ goto out_unregister;
klist_add_tail(&drv->knode_bus, &bus->klist_drivers);
module_add_driver(drv->owner, drv);
- driver_add_attrs(bus, drv);
- add_bind_files(drv);
+ error = driver_add_attrs(bus, drv);
+ if (error) {
+ /* How the hell do we get out of this pickle? Give up */
+ printk(KERN_ERR "%s: driver_add_attrs(%s) failed\n",
+ __FUNCTION__, drv->name);
+ }
+ error = add_bind_files(drv);
+ if (error) {
+ /* Ditto */
+ printk(KERN_ERR "%s: add_bind_files(%s) failed\n",
+ __FUNCTION__, drv->name);
+ }
}
return error;
+out_unregister:
+ kobject_unregister(&drv->kobj);
+out_put_bus:
+ put_bus(bus);
+ return error;
}
-
/**
* bus_remove_driver - delete driver from bus's knowledge.
* @drv: driver.
@@ -530,16 +566,21 @@ void bus_remove_driver(struct device_driver * drv)
/* Helper for bus_rescan_devices's iter */
-static int bus_rescan_devices_helper(struct device *dev, void *data)
+static int __must_check bus_rescan_devices_helper(struct device *dev,
+ void *data)
{
+ int ret = 0;
+
if (!dev->driver) {
if (dev->parent) /* Needed for USB */
down(&dev->parent->sem);
- device_attach(dev);
+ ret = device_attach(dev);
if (dev->parent)
up(&dev->parent->sem);
+ if (ret > 0)
+ ret = 0;
}
- return 0;
+ return ret < 0 ? ret : 0;
}
/**
@@ -550,9 +591,9 @@ static int bus_rescan_devices_helper(struct device *dev, void *data)
* attached and rescan it against existing drivers to see if it matches
* any by calling device_attach() for the unbound devices.
*/
-void bus_rescan_devices(struct bus_type * bus)
+int bus_rescan_devices(struct bus_type * bus)
{
- bus_for_each_dev(bus, NULL, NULL, bus_rescan_devices_helper);
+ return bus_for_each_dev(bus, NULL, NULL, bus_rescan_devices_helper);
}
/**
@@ -564,7 +605,7 @@ void bus_rescan_devices(struct bus_type * bus)
* to use if probing criteria changed during a devices lifetime and
* driver attachment should change accordingly.
*/
-void device_reprobe(struct device *dev)
+int device_reprobe(struct device *dev)
{
if (dev->driver) {
if (dev->parent) /* Needed for USB */
@@ -573,14 +614,14 @@ void device_reprobe(struct device *dev)
if (dev->parent)
up(&dev->parent->sem);
}
-
- bus_rescan_devices_helper(dev, NULL);
+ return bus_rescan_devices_helper(dev, NULL);
}
EXPORT_SYMBOL_GPL(device_reprobe);
-struct bus_type * get_bus(struct bus_type * bus)
+struct bus_type *get_bus(struct bus_type *bus)
{
- return bus ? container_of(subsys_get(&bus->subsys), struct bus_type, subsys) : NULL;
+ return bus ? container_of(subsys_get(&bus->subsys),
+ struct bus_type, subsys) : NULL;
}
void put_bus(struct bus_type * bus)
@@ -655,22 +696,6 @@ static void klist_devices_put(struct klist_node *n)
put_device(dev);
}
-static void klist_drivers_get(struct klist_node *n)
-{
- struct device_driver *drv = container_of(n, struct device_driver,
- knode_bus);
-
- get_driver(drv);
-}
-
-static void klist_drivers_put(struct klist_node *n)
-{
- struct device_driver *drv = container_of(n, struct device_driver,
- knode_bus);
-
- put_driver(drv);
-}
-
/**
* bus_register - register a bus with the system.
* @bus: bus.
@@ -706,7 +731,7 @@ int bus_register(struct bus_type * bus)
goto bus_drivers_fail;
klist_init(&bus->klist_devices, klist_devices_get, klist_devices_put);
- klist_init(&bus->klist_drivers, klist_drivers_get, klist_drivers_put);
+ klist_init(&bus->klist_drivers, NULL, NULL);
bus_add_attrs(bus);
pr_debug("bus type '%s' registered\n", bus->name);
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