From stern@rowland.harvard.edu Mon Sep 18 13:24:42 2006 Date: Mon, 18 Sep 2006 16:24:28 -0400 (EDT) From: Alan Stern To: Greg KH Subject: Driver core: Remove unneeded routines from driver core Message-ID: 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 Signed-off-by: Greg Kroah-Hartman --- drivers/base/bus.c | 18 +----------------- drivers/base/driver.c | 16 +--------------- 2 files changed, 2 insertions(+), 32 deletions(-) --- gregkh-2.6.orig/drivers/base/bus.c +++ gregkh-2.6/drivers/base/bus.c @@ -696,22 +696,6 @@ static void klist_devices_put(struct kli 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); --- gregkh-2.6.orig/drivers/base/driver.c +++ gregkh-2.6/drivers/base/driver.c @@ -142,20 +142,6 @@ void put_driver(struct device_driver * d 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->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); }