Driver core: Remove unneeded routines from driver core

This patch (as783) simplifies the driver core slightly by removing four
unnecessary _get and _put methods.

It is vital that when a driver is removed from its bus's klist of
registered drivers, or when a device is removed from a driver's klist
of bound devices, that the klist updates complete synchronously.
Otherwise the kernel might try binding an unregistered driver to a
newly-registered device, or adding a device to the klist for a new
driver before it has been removed from the old driver's klist.

Since the removals must be synchronous, they don't need to update any
reference counts.  Hence the _get and _put methods can be dispensed
with.

Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

diff --git a/drivers/base/bus.c b/drivers/base/bus.c
index 636af53..12173d1 100644 (file)
--- a/drivers/base/bus.c
+++ b/drivers/base/bus.c
@@ -696,22 +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.
@@ -747,7 +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);

diff --git a/drivers/base/driver.c b/drivers/base/driver.c
index 562600d..1214cbd 100644 (file)
--- a/drivers/base/driver.c
+++ b/drivers/base/driver.c
@@ -142,20 +142,6 @@ void put_driver(struct device_driver * drv)
        kobject_put(&drv->kobj);
 }
 
-static void klist_devices_get(struct klist_node *n)
-{
-       struct device *dev = container_of(n, struct device, knode_driver);
-
-       get_device(dev);
-}
-
-static void klist_devices_put(struct klist_node *n)
-{
-       struct device *dev = container_of(n, struct device, knode_driver);
-
-       put_device(dev);
-}
-
 /**
  *     driver_register - register driver with bus
  *     @drv:   driver to register
@@ -175,7 +161,7 @@ int driver_register(struct device_driver * drv)
            (drv->bus->shutdown && drv->shutdown)) {
                printk(KERN_WARNING "Driver '%s' needs updating - please use bus_type methods\n", drv->name);
        }
-       klist_init(&drv->klist_devices, klist_devices_get, klist_devices_put);
+       klist_init(&drv->klist_devices, NULL, NULL);
        init_completion(&drv->unloaded);
        return bus_add_driver(drv);
 }