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mochel@digitalimplant.org07e4a3e2005-03-21 10:52:54 -08001/*
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -08002 * drivers/base/dd.c - The core device/driver interactions.
mochel@digitalimplant.org07e4a3e2005-03-21 10:52:54 -08003 *
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -08004 * This file contains the (sometimes tricky) code that controls the
5 * interactions between devices and drivers, which primarily includes
6 * driver binding and unbinding.
mochel@digitalimplant.org07e4a3e2005-03-21 10:52:54 -08007 *
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -08008 * All of this code used to exist in drivers/base/bus.c, but was
9 * relocated to here in the name of compartmentalization (since it wasn't
10 * strictly code just for the 'struct bus_type'.
mochel@digitalimplant.org07e4a3e2005-03-21 10:52:54 -080011 *
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -080012 * Copyright (c) 2002-5 Patrick Mochel
13 * Copyright (c) 2002-3 Open Source Development Labs
14 * Copyright (c) 2007 Greg Kroah-Hartman <gregkh@suse.de>
15 * Copyright (c) 2007 Novell Inc.
mochel@digitalimplant.org07e4a3e2005-03-21 10:52:54 -080016 *
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -080017 * This file is released under the GPLv2
mochel@digitalimplant.org07e4a3e2005-03-21 10:52:54 -080018 */
19
20#include <linux/device.h>
Arjan van de Ven216773a2009-02-14 01:59:06 +010021#include <linux/delay.h>
mochel@digitalimplant.org07e4a3e2005-03-21 10:52:54 -080022#include <linux/module.h>
Greg Kroah-Hartmand7792492006-07-18 10:59:59 -070023#include <linux/kthread.h>
Andrew Morton735a7ff2006-10-27 11:42:37 -070024#include <linux/wait.h>
Arjan van de Ven216773a2009-02-14 01:59:06 +010025#include <linux/async.h>
mochel@digitalimplant.org07e4a3e2005-03-21 10:52:54 -080026
27#include "base.h"
28#include "power/power.h"
29
mochel@digitalimplant.org07e4a3e2005-03-21 10:52:54 -080030
Kay Sievers1901fb22006-10-07 21:55:55 +020031static void driver_bound(struct device *dev)
32{
Greg Kroah-Hartman8940b4f2008-12-16 12:25:49 -080033 if (klist_node_attached(&dev->p->knode_driver)) {
Kay Sievers1901fb22006-10-07 21:55:55 +020034 printk(KERN_WARNING "%s: device %s already bound\n",
Harvey Harrison2b3a3022008-03-04 16:41:05 -080035 __func__, kobject_name(&dev->kobj));
Kay Sievers1901fb22006-10-07 21:55:55 +020036 return;
37 }
38
Kay Sievers1e0b2cf2008-10-30 01:36:48 +010039 pr_debug("driver: '%s': %s: bound to device '%s'\n", dev_name(dev),
Harvey Harrison2b3a3022008-03-04 16:41:05 -080040 __func__, dev->driver->name);
Kay Sievers1901fb22006-10-07 21:55:55 +020041
42 if (dev->bus)
Greg Kroah-Hartmanc6f7e722007-11-01 19:41:16 -070043 blocking_notifier_call_chain(&dev->bus->p->bus_notifier,
Kay Sievers1901fb22006-10-07 21:55:55 +020044 BUS_NOTIFY_BOUND_DRIVER, dev);
45
Greg Kroah-Hartman8940b4f2008-12-16 12:25:49 -080046 klist_add_tail(&dev->p->knode_driver, &dev->driver->p->klist_devices);
Kay Sievers1901fb22006-10-07 21:55:55 +020047}
48
49static int driver_sysfs_add(struct device *dev)
50{
51 int ret;
52
Greg Kroah-Hartmane5dd1272007-11-28 15:59:15 -080053 ret = sysfs_create_link(&dev->driver->p->kobj, &dev->kobj,
Kay Sievers1901fb22006-10-07 21:55:55 +020054 kobject_name(&dev->kobj));
55 if (ret == 0) {
Greg Kroah-Hartmane5dd1272007-11-28 15:59:15 -080056 ret = sysfs_create_link(&dev->kobj, &dev->driver->p->kobj,
Kay Sievers1901fb22006-10-07 21:55:55 +020057 "driver");
58 if (ret)
Greg Kroah-Hartmane5dd1272007-11-28 15:59:15 -080059 sysfs_remove_link(&dev->driver->p->kobj,
Kay Sievers1901fb22006-10-07 21:55:55 +020060 kobject_name(&dev->kobj));
61 }
62 return ret;
63}
64
65static void driver_sysfs_remove(struct device *dev)
66{
67 struct device_driver *drv = dev->driver;
68
69 if (drv) {
Greg Kroah-Hartmane5dd1272007-11-28 15:59:15 -080070 sysfs_remove_link(&drv->p->kobj, kobject_name(&dev->kobj));
Kay Sievers1901fb22006-10-07 21:55:55 +020071 sysfs_remove_link(&dev->kobj, "driver");
72 }
73}
74
mochel@digitalimplant.org07e4a3e2005-03-21 10:52:54 -080075/**
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -080076 * device_bind_driver - bind a driver to one device.
77 * @dev: device.
mochel@digitalimplant.org07e4a3e2005-03-21 10:52:54 -080078 *
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -080079 * Allow manual attachment of a driver to a device.
80 * Caller must have already set @dev->driver.
mochel@digitalimplant.org07e4a3e2005-03-21 10:52:54 -080081 *
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -080082 * Note that this does not modify the bus reference count
83 * nor take the bus's rwsem. Please verify those are accounted
84 * for before calling this. (It is ok to call with no other effort
85 * from a driver's probe() method.)
Patrick Mochel0d3e5a22005-04-05 23:46:33 -070086 *
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -080087 * This function must be called with @dev->sem held.
mochel@digitalimplant.org07e4a3e2005-03-21 10:52:54 -080088 */
Andrew Mortonf86db392006-08-14 22:43:20 -070089int device_bind_driver(struct device *dev)
mochel@digitalimplant.org07e4a3e2005-03-21 10:52:54 -080090{
Cornelia Huckcb986b72006-11-27 10:35:12 +010091 int ret;
92
93 ret = driver_sysfs_add(dev);
94 if (!ret)
95 driver_bound(dev);
96 return ret;
mochel@digitalimplant.org07e4a3e2005-03-21 10:52:54 -080097}
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -080098EXPORT_SYMBOL_GPL(device_bind_driver);
mochel@digitalimplant.org07e4a3e2005-03-21 10:52:54 -080099
Greg Kroah-Hartmand7792492006-07-18 10:59:59 -0700100static atomic_t probe_count = ATOMIC_INIT(0);
Andrew Morton735a7ff2006-10-27 11:42:37 -0700101static DECLARE_WAIT_QUEUE_HEAD(probe_waitqueue);
102
Cornelia Huck21c7f302007-02-05 16:15:25 -0800103static int really_probe(struct device *dev, struct device_driver *drv)
mochel@digitalimplant.org07e4a3e2005-03-21 10:52:54 -0800104{
Patrick Mochel0d3e5a22005-04-05 23:46:33 -0700105 int ret = 0;
mochel@digitalimplant.org07e4a3e2005-03-21 10:52:54 -0800106
Greg Kroah-Hartmand7792492006-07-18 10:59:59 -0700107 atomic_inc(&probe_count);
Greg Kroah-Hartman7dc72b22007-11-28 23:49:41 -0800108 pr_debug("bus: '%s': %s: probing driver %s with device %s\n",
Kay Sievers1e0b2cf2008-10-30 01:36:48 +0100109 drv->bus->name, __func__, drv->name, dev_name(dev));
Tejun Heo9ac78492007-01-20 16:00:26 +0900110 WARN_ON(!list_empty(&dev->devres_head));
mochel@digitalimplant.org07e4a3e2005-03-21 10:52:54 -0800111
mochel@digitalimplant.org07e4a3e2005-03-21 10:52:54 -0800112 dev->driver = drv;
Kay Sievers1901fb22006-10-07 21:55:55 +0200113 if (driver_sysfs_add(dev)) {
114 printk(KERN_ERR "%s: driver_sysfs_add(%s) failed\n",
Kay Sievers1e0b2cf2008-10-30 01:36:48 +0100115 __func__, dev_name(dev));
Kay Sievers1901fb22006-10-07 21:55:55 +0200116 goto probe_failed;
117 }
118
Russell King594c8282006-01-05 14:29:51 +0000119 if (dev->bus->probe) {
120 ret = dev->bus->probe(dev);
Kay Sievers1901fb22006-10-07 21:55:55 +0200121 if (ret)
Greg Kroah-Hartmand7792492006-07-18 10:59:59 -0700122 goto probe_failed;
Russell King594c8282006-01-05 14:29:51 +0000123 } else if (drv->probe) {
Patrick Mochel0d3e5a22005-04-05 23:46:33 -0700124 ret = drv->probe(dev);
Kay Sievers1901fb22006-10-07 21:55:55 +0200125 if (ret)
Greg Kroah-Hartmand7792492006-07-18 10:59:59 -0700126 goto probe_failed;
mochel@digitalimplant.org07e4a3e2005-03-21 10:52:54 -0800127 }
Kay Sievers1901fb22006-10-07 21:55:55 +0200128
129 driver_bound(dev);
Patrick Mochel0d3e5a22005-04-05 23:46:33 -0700130 ret = 1;
Greg Kroah-Hartman7dc72b22007-11-28 23:49:41 -0800131 pr_debug("bus: '%s': %s: bound device %s to driver %s\n",
Kay Sievers1e0b2cf2008-10-30 01:36:48 +0100132 drv->bus->name, __func__, dev_name(dev), drv->name);
Greg Kroah-Hartmand7792492006-07-18 10:59:59 -0700133 goto done;
Patrick Mochel0d3e5a22005-04-05 23:46:33 -0700134
Greg Kroah-Hartmand7792492006-07-18 10:59:59 -0700135probe_failed:
Tejun Heo9ac78492007-01-20 16:00:26 +0900136 devres_release_all(dev);
Kay Sievers1901fb22006-10-07 21:55:55 +0200137 driver_sysfs_remove(dev);
138 dev->driver = NULL;
139
Cornelia Huckc578abb2006-11-27 10:35:10 +0100140 if (ret != -ENODEV && ret != -ENXIO) {
Patrick Mochel0d3e5a22005-04-05 23:46:33 -0700141 /* driver matched but the probe failed */
142 printk(KERN_WARNING
143 "%s: probe of %s failed with error %d\n",
Kay Sievers1e0b2cf2008-10-30 01:36:48 +0100144 drv->name, dev_name(dev), ret);
Patrick Mochel0d3e5a22005-04-05 23:46:33 -0700145 }
Cornelia Huckc578abb2006-11-27 10:35:10 +0100146 /*
147 * Ignore errors returned by ->probe so that the next driver can try
148 * its luck.
149 */
150 ret = 0;
Greg Kroah-Hartmand7792492006-07-18 10:59:59 -0700151done:
Greg Kroah-Hartmand7792492006-07-18 10:59:59 -0700152 atomic_dec(&probe_count);
Andrew Morton735a7ff2006-10-27 11:42:37 -0700153 wake_up(&probe_waitqueue);
Greg Kroah-Hartmand7792492006-07-18 10:59:59 -0700154 return ret;
155}
156
157/**
158 * driver_probe_done
159 * Determine if the probe sequence is finished or not.
160 *
161 * Should somehow figure out how to use a semaphore, not an atomic variable...
162 */
163int driver_probe_done(void)
164{
Harvey Harrison2b3a3022008-03-04 16:41:05 -0800165 pr_debug("%s: probe_count = %d\n", __func__,
Greg Kroah-Hartmand7792492006-07-18 10:59:59 -0700166 atomic_read(&probe_count));
167 if (atomic_read(&probe_count))
168 return -EBUSY;
169 return 0;
170}
171
172/**
Arjan van de Ven216773a2009-02-14 01:59:06 +0100173 * wait_for_device_probe
174 * Wait for device probing to be completed.
Arjan van de Ven216773a2009-02-14 01:59:06 +0100175 */
Ming Leib23530e2009-02-21 16:45:07 +0800176void wait_for_device_probe(void)
Arjan van de Ven216773a2009-02-14 01:59:06 +0100177{
178 /* wait for the known devices to complete their probing */
Ming Leib23530e2009-02-21 16:45:07 +0800179 wait_event(probe_waitqueue, atomic_read(&probe_count) == 0);
Arjan van de Ven216773a2009-02-14 01:59:06 +0100180 async_synchronize_full();
Arjan van de Ven216773a2009-02-14 01:59:06 +0100181}
Arjan van de Vend4d52912009-04-21 13:32:54 -0700182EXPORT_SYMBOL_GPL(wait_for_device_probe);
Arjan van de Ven216773a2009-02-14 01:59:06 +0100183
184/**
Greg Kroah-Hartmand7792492006-07-18 10:59:59 -0700185 * driver_probe_device - attempt to bind device & driver together
186 * @drv: driver to bind a device to
187 * @dev: device to try to bind to the driver
188 *
Ming Lei49b420a2009-01-21 23:27:47 +0800189 * This function returns -ENODEV if the device is not registered,
190 * 1 if the device is bound sucessfully and 0 otherwise.
Greg Kroah-Hartmand7792492006-07-18 10:59:59 -0700191 *
192 * This function must be called with @dev->sem held. When called for a
193 * USB interface, @dev->parent->sem must be held as well.
194 */
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800195int driver_probe_device(struct device_driver *drv, struct device *dev)
Greg Kroah-Hartmand7792492006-07-18 10:59:59 -0700196{
Greg Kroah-Hartmand7792492006-07-18 10:59:59 -0700197 int ret = 0;
198
Alan Sternf2eaae12006-09-18 16:22:34 -0400199 if (!device_is_registered(dev))
200 return -ENODEV;
Greg Kroah-Hartmand7792492006-07-18 10:59:59 -0700201
Greg Kroah-Hartman7dc72b22007-11-28 23:49:41 -0800202 pr_debug("bus: '%s': %s: matched device %s with driver %s\n",
Kay Sievers1e0b2cf2008-10-30 01:36:48 +0100203 drv->bus->name, __func__, dev_name(dev), drv->name);
Greg Kroah-Hartmand7792492006-07-18 10:59:59 -0700204
Cornelia Huck21c7f302007-02-05 16:15:25 -0800205 ret = really_probe(dev, drv);
Greg Kroah-Hartmand7792492006-07-18 10:59:59 -0700206
Patrick Mochel0d3e5a22005-04-05 23:46:33 -0700207 return ret;
mochel@digitalimplant.org07e4a3e2005-03-21 10:52:54 -0800208}
209
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800210static int __device_attach(struct device_driver *drv, void *data)
mochel@digitalimplant.org2287c322005-03-24 10:50:24 -0800211{
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800212 struct device *dev = data;
Ming Lei49b420a2009-01-21 23:27:47 +0800213
214 if (!driver_match_device(drv, dev))
215 return 0;
216
Patrick Mochel0d3e5a22005-04-05 23:46:33 -0700217 return driver_probe_device(drv, dev);
mochel@digitalimplant.org2287c322005-03-24 10:50:24 -0800218}
219
mochel@digitalimplant.org07e4a3e2005-03-21 10:52:54 -0800220/**
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800221 * device_attach - try to attach device to a driver.
222 * @dev: device.
mochel@digitalimplant.org07e4a3e2005-03-21 10:52:54 -0800223 *
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800224 * Walk the list of drivers that the bus has and call
225 * driver_probe_device() for each pair. If a compatible
226 * pair is found, break out and return.
Patrick Mochel0d3e5a22005-04-05 23:46:33 -0700227 *
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800228 * Returns 1 if the device was bound to a driver;
229 * 0 if no matching device was found;
230 * -ENODEV if the device is not registered.
Alan Sternbf74ad52005-11-17 16:54:12 -0500231 *
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800232 * When called for a USB interface, @dev->parent->sem must be held.
mochel@digitalimplant.org07e4a3e2005-03-21 10:52:54 -0800233 */
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800234int device_attach(struct device *dev)
mochel@digitalimplant.org07e4a3e2005-03-21 10:52:54 -0800235{
Patrick Mochel0d3e5a22005-04-05 23:46:33 -0700236 int ret = 0;
237
238 down(&dev->sem);
mochel@digitalimplant.org07e4a3e2005-03-21 10:52:54 -0800239 if (dev->driver) {
Andrew Mortonf86db392006-08-14 22:43:20 -0700240 ret = device_bind_driver(dev);
241 if (ret == 0)
242 ret = 1;
Cornelia Huckc6a46692007-02-05 16:15:26 -0800243 else {
244 dev->driver = NULL;
245 ret = 0;
246 }
Cornelia Huck21c7f302007-02-05 16:15:25 -0800247 } else {
Adrian Bunk5adc55d2007-03-27 03:02:51 +0200248 ret = bus_for_each_drv(dev->bus, NULL, dev, __device_attach);
Cornelia Huck21c7f302007-02-05 16:15:25 -0800249 }
Patrick Mochel0d3e5a22005-04-05 23:46:33 -0700250 up(&dev->sem);
251 return ret;
mochel@digitalimplant.org2287c322005-03-24 10:50:24 -0800252}
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800253EXPORT_SYMBOL_GPL(device_attach);
mochel@digitalimplant.org2287c322005-03-24 10:50:24 -0800254
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800255static int __driver_attach(struct device *dev, void *data)
mochel@digitalimplant.org2287c322005-03-24 10:50:24 -0800256{
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800257 struct device_driver *drv = data;
mochel@digitalimplant.org2287c322005-03-24 10:50:24 -0800258
Patrick Mochel0d3e5a22005-04-05 23:46:33 -0700259 /*
260 * Lock device and try to bind to it. We drop the error
261 * here and always return 0, because we need to keep trying
262 * to bind to devices and some drivers will return an error
263 * simply if it didn't support the device.
264 *
265 * driver_probe_device() will spit a warning if there
266 * is an error.
267 */
268
Ming Lei49b420a2009-01-21 23:27:47 +0800269 if (!driver_match_device(drv, dev))
Arjan van de Ven6cd49582008-09-14 08:32:06 -0700270 return 0;
271
Alan Sternbf74ad52005-11-17 16:54:12 -0500272 if (dev->parent) /* Needed for USB */
273 down(&dev->parent->sem);
Patrick Mochel0d3e5a22005-04-05 23:46:33 -0700274 down(&dev->sem);
275 if (!dev->driver)
276 driver_probe_device(drv, dev);
277 up(&dev->sem);
Alan Sternbf74ad52005-11-17 16:54:12 -0500278 if (dev->parent)
279 up(&dev->parent->sem);
Patrick Mochel0d3e5a22005-04-05 23:46:33 -0700280
mochel@digitalimplant.org07e4a3e2005-03-21 10:52:54 -0800281 return 0;
282}
283
284/**
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800285 * driver_attach - try to bind driver to devices.
286 * @drv: driver.
mochel@digitalimplant.org07e4a3e2005-03-21 10:52:54 -0800287 *
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800288 * Walk the list of devices that the bus has on it and try to
289 * match the driver with each one. If driver_probe_device()
290 * returns 0 and the @dev->driver is set, we've found a
291 * compatible pair.
mochel@digitalimplant.org07e4a3e2005-03-21 10:52:54 -0800292 */
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800293int driver_attach(struct device_driver *drv)
mochel@digitalimplant.org07e4a3e2005-03-21 10:52:54 -0800294{
Andrew Mortonf86db392006-08-14 22:43:20 -0700295 return bus_for_each_dev(drv->bus, NULL, drv, __driver_attach);
mochel@digitalimplant.org07e4a3e2005-03-21 10:52:54 -0800296}
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800297EXPORT_SYMBOL_GPL(driver_attach);
mochel@digitalimplant.org07e4a3e2005-03-21 10:52:54 -0800298
Stefan Richterab71c6f2007-06-17 11:02:12 +0200299/*
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800300 * __device_release_driver() must be called with @dev->sem held.
301 * When called for a USB interface, @dev->parent->sem must be held as well.
mochel@digitalimplant.org07e4a3e2005-03-21 10:52:54 -0800302 */
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800303static void __device_release_driver(struct device *dev)
mochel@digitalimplant.org07e4a3e2005-03-21 10:52:54 -0800304{
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800305 struct device_driver *drv;
mochel@digitalimplant.org07e4a3e2005-03-21 10:52:54 -0800306
Alan Sternef2c5172007-11-16 11:57:28 -0500307 drv = dev->driver;
Alan Sternc95a6b02005-05-06 15:38:33 -0400308 if (drv) {
Kay Sievers1901fb22006-10-07 21:55:55 +0200309 driver_sysfs_remove(dev);
Patrick Mochel0d3e5a22005-04-05 23:46:33 -0700310
Benjamin Herrenschmidt116af372006-10-25 13:44:59 +1000311 if (dev->bus)
Greg Kroah-Hartmanc6f7e722007-11-01 19:41:16 -0700312 blocking_notifier_call_chain(&dev->bus->p->bus_notifier,
Benjamin Herrenschmidt116af372006-10-25 13:44:59 +1000313 BUS_NOTIFY_UNBIND_DRIVER,
314 dev);
315
Alan Stern0f836ca2006-03-31 11:52:25 -0500316 if (dev->bus && dev->bus->remove)
Russell King594c8282006-01-05 14:29:51 +0000317 dev->bus->remove(dev);
318 else if (drv->remove)
Patrick Mochel0d3e5a22005-04-05 23:46:33 -0700319 drv->remove(dev);
Tejun Heo9ac78492007-01-20 16:00:26 +0900320 devres_release_all(dev);
Patrick Mochel0d3e5a22005-04-05 23:46:33 -0700321 dev->driver = NULL;
Greg Kroah-Hartman8940b4f2008-12-16 12:25:49 -0800322 klist_remove(&dev->p->knode_driver);
Patrick Mochel0d3e5a22005-04-05 23:46:33 -0700323 }
Alan Sternc95a6b02005-05-06 15:38:33 -0400324}
325
Stefan Richterab71c6f2007-06-17 11:02:12 +0200326/**
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800327 * device_release_driver - manually detach device from driver.
328 * @dev: device.
Stefan Richterab71c6f2007-06-17 11:02:12 +0200329 *
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800330 * Manually detach device from driver.
331 * When called for a USB interface, @dev->parent->sem must be held.
Stefan Richterab71c6f2007-06-17 11:02:12 +0200332 */
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800333void device_release_driver(struct device *dev)
Alan Sternc95a6b02005-05-06 15:38:33 -0400334{
335 /*
336 * If anyone calls device_release_driver() recursively from
337 * within their ->remove callback for the same device, they
338 * will deadlock right here.
339 */
340 down(&dev->sem);
341 __device_release_driver(dev);
mochel@digitalimplant.org07e4a3e2005-03-21 10:52:54 -0800342 up(&dev->sem);
343}
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800344EXPORT_SYMBOL_GPL(device_release_driver);
mochel@digitalimplant.org94e7b1c52005-03-21 12:25:36 -0800345
mochel@digitalimplant.org07e4a3e2005-03-21 10:52:54 -0800346/**
347 * driver_detach - detach driver from all devices it controls.
348 * @drv: driver.
349 */
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800350void driver_detach(struct device_driver *drv)
mochel@digitalimplant.org07e4a3e2005-03-21 10:52:54 -0800351{
Greg Kroah-Hartman8940b4f2008-12-16 12:25:49 -0800352 struct device_private *dev_prv;
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800353 struct device *dev;
Alan Sternc95a6b02005-05-06 15:38:33 -0400354
355 for (;;) {
Greg Kroah-Hartmane5dd1272007-11-28 15:59:15 -0800356 spin_lock(&drv->p->klist_devices.k_lock);
357 if (list_empty(&drv->p->klist_devices.k_list)) {
358 spin_unlock(&drv->p->klist_devices.k_lock);
Alan Sternc95a6b02005-05-06 15:38:33 -0400359 break;
360 }
Greg Kroah-Hartman8940b4f2008-12-16 12:25:49 -0800361 dev_prv = list_entry(drv->p->klist_devices.k_list.prev,
362 struct device_private,
363 knode_driver.n_node);
364 dev = dev_prv->device;
Alan Sternc95a6b02005-05-06 15:38:33 -0400365 get_device(dev);
Greg Kroah-Hartmane5dd1272007-11-28 15:59:15 -0800366 spin_unlock(&drv->p->klist_devices.k_lock);
Alan Sternc95a6b02005-05-06 15:38:33 -0400367
Alan Sternbf74ad52005-11-17 16:54:12 -0500368 if (dev->parent) /* Needed for USB */
369 down(&dev->parent->sem);
Alan Sternc95a6b02005-05-06 15:38:33 -0400370 down(&dev->sem);
371 if (dev->driver == drv)
372 __device_release_driver(dev);
373 up(&dev->sem);
Alan Sternbf74ad52005-11-17 16:54:12 -0500374 if (dev->parent)
375 up(&dev->parent->sem);
Alan Sternc95a6b02005-05-06 15:38:33 -0400376 put_device(dev);
377 }
mochel@digitalimplant.org07e4a3e2005-03-21 10:52:54 -0800378}