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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.c41
1 files changed, 36 insertions, 5 deletions
diff --git a/drivers/base/bus.c b/drivers/base/bus.c
index fa601b085eb..29f6af554e7 100644
--- a/drivers/base/bus.c
+++ b/drivers/base/bus.c
@@ -152,7 +152,11 @@ static ssize_t driver_unbind(struct device_driver *drv,
dev = bus_find_device(bus, NULL, (void *)buf, driver_helper);
if (dev && dev->driver == drv) {
+ if (dev->parent) /* Needed for USB */
+ down(&dev->parent->sem);
device_release_driver(dev);
+ if (dev->parent)
+ up(&dev->parent->sem);
err = count;
}
put_device(dev);
@@ -175,9 +179,13 @@ static ssize_t driver_bind(struct device_driver *drv,
dev = bus_find_device(bus, NULL, (void *)buf, driver_helper);
if (dev && dev->driver == NULL) {
+ if (dev->parent) /* Needed for USB */
+ down(&dev->parent->sem);
down(&dev->sem);
err = driver_probe_device(drv, dev);
up(&dev->sem);
+ if (dev->parent)
+ up(&dev->parent->sem);
}
put_device(dev);
put_bus(bus);
@@ -420,6 +428,26 @@ static void driver_remove_attrs(struct bus_type * bus, struct device_driver * dr
}
}
+#ifdef CONFIG_HOTPLUG
+/*
+ * 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)
+{
+ driver_create_file(drv, &driver_attr_unbind);
+ driver_create_file(drv, &driver_attr_bind);
+}
+
+static void remove_bind_files(struct device_driver *drv)
+{
+ driver_remove_file(drv, &driver_attr_bind);
+ driver_remove_file(drv, &driver_attr_unbind);
+}
+#else
+static inline void add_bind_files(struct device_driver *drv) {}
+static inline void remove_bind_files(struct device_driver *drv) {}
+#endif
/**
* bus_add_driver - Add a driver to the bus.
@@ -449,8 +477,7 @@ int bus_add_driver(struct device_driver * drv)
module_add_driver(drv->owner, drv);
driver_add_attrs(bus, drv);
- driver_create_file(drv, &driver_attr_unbind);
- driver_create_file(drv, &driver_attr_bind);
+ add_bind_files(drv);
}
return error;
}
@@ -468,8 +495,7 @@ int bus_add_driver(struct device_driver * drv)
void bus_remove_driver(struct device_driver * drv)
{
if (drv->bus) {
- driver_remove_file(drv, &driver_attr_bind);
- driver_remove_file(drv, &driver_attr_unbind);
+ remove_bind_files(drv);
driver_remove_attrs(drv->bus, drv);
klist_remove(&drv->knode_bus);
pr_debug("bus %s: remove driver %s\n", drv->bus->name, drv->name);
@@ -484,8 +510,13 @@ 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)
{
- if (!dev->driver)
+ if (!dev->driver) {
+ if (dev->parent) /* Needed for USB */
+ down(&dev->parent->sem);
device_attach(dev);
+ if (dev->parent)
+ up(&dev->parent->sem);
+ }
return 0;
}