blob: d22a7260f42b26f498037f35c943b547300181dc [file] [log] [blame]
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
Greg Kroah-Hartmanb4028432009-05-11 14:16:57 -070014 * Copyright (c) 2007-2009 Greg Kroah-Hartman <gregkh@suse.de>
15 * Copyright (c) 2007-2009 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>
Rafael J. Wysocki5e928f72009-08-18 23:38:32 +020026#include <linux/pm_runtime.h>
Linus Walleijab780292013-01-22 10:56:14 -070027#include <linux/pinctrl/devinfo.h>
mochel@digitalimplant.org07e4a3e2005-03-21 10:52:54 -080028
29#include "base.h"
30#include "power/power.h"
31
Grant Likelyd1c34142012-03-05 08:47:41 -070032/*
33 * Deferred Probe infrastructure.
34 *
35 * Sometimes driver probe order matters, but the kernel doesn't always have
36 * dependency information which means some drivers will get probed before a
37 * resource it depends on is available. For example, an SDHCI driver may
38 * first need a GPIO line from an i2c GPIO controller before it can be
39 * initialized. If a required resource is not available yet, a driver can
40 * request probing to be deferred by returning -EPROBE_DEFER from its probe hook
41 *
42 * Deferred probe maintains two lists of devices, a pending list and an active
43 * list. A driver returning -EPROBE_DEFER causes the device to be added to the
44 * pending list. A successful driver probe will trigger moving all devices
45 * from the pending to the active list so that the workqueue will eventually
46 * retry them.
47 *
48 * The deferred_probe_mutex must be held any time the deferred_probe_*_list
Greg Kroah-Hartmanef8a3fd2012-03-08 12:17:22 -080049 * of the (struct device*)->p->deferred_probe pointers are manipulated
Grant Likelyd1c34142012-03-05 08:47:41 -070050 */
51static DEFINE_MUTEX(deferred_probe_mutex);
52static LIST_HEAD(deferred_probe_pending_list);
53static LIST_HEAD(deferred_probe_active_list);
Grant Likely58b116b2014-04-29 12:05:22 +010054static atomic_t deferred_trigger_count = ATOMIC_INIT(0);
Grant Likelyd1c34142012-03-05 08:47:41 -070055
Thierry Reding41575332014-08-08 15:56:36 +020056/*
Strashko, Grygorii013c0742015-11-10 11:42:34 +020057 * In some cases, like suspend to RAM or hibernation, It might be reasonable
58 * to prohibit probing of devices as it could be unsafe.
59 * Once defer_all_probes is true all drivers probes will be forcibly deferred.
60 */
61static bool defer_all_probes;
62
63/*
Grant Likelyd1c34142012-03-05 08:47:41 -070064 * deferred_probe_work_func() - Retry probing devices in the active list.
65 */
66static void deferred_probe_work_func(struct work_struct *work)
67{
68 struct device *dev;
Greg Kroah-Hartmanef8a3fd2012-03-08 12:17:22 -080069 struct device_private *private;
Grant Likelyd1c34142012-03-05 08:47:41 -070070 /*
71 * This block processes every device in the deferred 'active' list.
72 * Each device is removed from the active list and passed to
73 * bus_probe_device() to re-attempt the probe. The loop continues
74 * until every device in the active list is removed and retried.
75 *
76 * Note: Once the device is removed from the list and the mutex is
77 * released, it is possible for the device get freed by another thread
78 * and cause a illegal pointer dereference. This code uses
79 * get/put_device() to ensure the device structure cannot disappear
80 * from under our feet.
81 */
82 mutex_lock(&deferred_probe_mutex);
83 while (!list_empty(&deferred_probe_active_list)) {
Greg Kroah-Hartmanef8a3fd2012-03-08 12:17:22 -080084 private = list_first_entry(&deferred_probe_active_list,
85 typeof(*dev->p), deferred_probe);
86 dev = private->device;
87 list_del_init(&private->deferred_probe);
Grant Likelyd1c34142012-03-05 08:47:41 -070088
89 get_device(dev);
90
Greg Kroah-Hartman8b0372a2012-03-08 12:20:37 -080091 /*
92 * Drop the mutex while probing each device; the probe path may
93 * manipulate the deferred list
94 */
Grant Likelyd1c34142012-03-05 08:47:41 -070095 mutex_unlock(&deferred_probe_mutex);
Mark Brown81535842012-07-05 14:04:44 +010096
97 /*
98 * Force the device to the end of the dpm_list since
99 * the PM code assumes that the order we add things to
100 * the list is a good order for suspend but deferred
101 * probe makes that very unsafe.
102 */
103 device_pm_lock();
104 device_pm_move_last(dev);
105 device_pm_unlock();
106
Grant Likelyd1c34142012-03-05 08:47:41 -0700107 dev_dbg(dev, "Retrying from deferred list\n");
108 bus_probe_device(dev);
Mark Brown81535842012-07-05 14:04:44 +0100109
Grant Likelyd1c34142012-03-05 08:47:41 -0700110 mutex_lock(&deferred_probe_mutex);
111
112 put_device(dev);
113 }
114 mutex_unlock(&deferred_probe_mutex);
115}
116static DECLARE_WORK(deferred_probe_work, deferred_probe_work_func);
117
118static void driver_deferred_probe_add(struct device *dev)
119{
120 mutex_lock(&deferred_probe_mutex);
Greg Kroah-Hartmanef8a3fd2012-03-08 12:17:22 -0800121 if (list_empty(&dev->p->deferred_probe)) {
Grant Likelyd1c34142012-03-05 08:47:41 -0700122 dev_dbg(dev, "Added to deferred list\n");
Kuninori Morimoto1d29cfa2012-05-29 18:46:06 -0700123 list_add_tail(&dev->p->deferred_probe, &deferred_probe_pending_list);
Grant Likelyd1c34142012-03-05 08:47:41 -0700124 }
125 mutex_unlock(&deferred_probe_mutex);
126}
127
128void driver_deferred_probe_del(struct device *dev)
129{
130 mutex_lock(&deferred_probe_mutex);
Greg Kroah-Hartmanef8a3fd2012-03-08 12:17:22 -0800131 if (!list_empty(&dev->p->deferred_probe)) {
Grant Likelyd1c34142012-03-05 08:47:41 -0700132 dev_dbg(dev, "Removed from deferred list\n");
Greg Kroah-Hartmanef8a3fd2012-03-08 12:17:22 -0800133 list_del_init(&dev->p->deferred_probe);
Grant Likelyd1c34142012-03-05 08:47:41 -0700134 }
135 mutex_unlock(&deferred_probe_mutex);
136}
137
138static bool driver_deferred_probe_enable = false;
139/**
140 * driver_deferred_probe_trigger() - Kick off re-probing deferred devices
141 *
142 * This functions moves all devices from the pending list to the active
143 * list and schedules the deferred probe workqueue to process them. It
144 * should be called anytime a driver is successfully bound to a device.
Grant Likely58b116b2014-04-29 12:05:22 +0100145 *
146 * Note, there is a race condition in multi-threaded probe. In the case where
147 * more than one device is probing at the same time, it is possible for one
148 * probe to complete successfully while another is about to defer. If the second
149 * depends on the first, then it will get put on the pending list after the
Shailendra Verma9ba8af62015-05-25 23:46:11 +0530150 * trigger event has already occurred and will be stuck there.
Grant Likely58b116b2014-04-29 12:05:22 +0100151 *
152 * The atomic 'deferred_trigger_count' is used to determine if a successful
153 * trigger has occurred in the midst of probing a driver. If the trigger count
154 * changes in the midst of a probe, then deferred processing should be triggered
155 * again.
Grant Likelyd1c34142012-03-05 08:47:41 -0700156 */
157static void driver_deferred_probe_trigger(void)
158{
159 if (!driver_deferred_probe_enable)
160 return;
161
Greg Kroah-Hartman8b0372a2012-03-08 12:20:37 -0800162 /*
163 * A successful probe means that all the devices in the pending list
Grant Likelyd1c34142012-03-05 08:47:41 -0700164 * should be triggered to be reprobed. Move all the deferred devices
Greg Kroah-Hartman8b0372a2012-03-08 12:20:37 -0800165 * into the active list so they can be retried by the workqueue
166 */
Grant Likelyd1c34142012-03-05 08:47:41 -0700167 mutex_lock(&deferred_probe_mutex);
Grant Likely58b116b2014-04-29 12:05:22 +0100168 atomic_inc(&deferred_trigger_count);
Grant Likelyd1c34142012-03-05 08:47:41 -0700169 list_splice_tail_init(&deferred_probe_pending_list,
170 &deferred_probe_active_list);
171 mutex_unlock(&deferred_probe_mutex);
172
Greg Kroah-Hartman8b0372a2012-03-08 12:20:37 -0800173 /*
174 * Kick the re-probe thread. It may already be scheduled, but it is
175 * safe to kick it again.
176 */
Bhaktipriya Shridhar2c507e42016-08-30 22:45:34 +0530177 schedule_work(&deferred_probe_work);
Grant Likelyd1c34142012-03-05 08:47:41 -0700178}
179
180/**
Strashko, Grygorii013c0742015-11-10 11:42:34 +0200181 * device_block_probing() - Block/defere device's probes
182 *
183 * It will disable probing of devices and defer their probes instead.
184 */
185void device_block_probing(void)
186{
187 defer_all_probes = true;
188 /* sync with probes to avoid races. */
189 wait_for_device_probe();
190}
191
192/**
193 * device_unblock_probing() - Unblock/enable device's probes
194 *
195 * It will restore normal behavior and trigger re-probing of deferred
196 * devices.
197 */
198void device_unblock_probing(void)
199{
200 defer_all_probes = false;
201 driver_deferred_probe_trigger();
202}
203
204/**
Grant Likelyd1c34142012-03-05 08:47:41 -0700205 * deferred_probe_initcall() - Enable probing of deferred devices
206 *
207 * We don't want to get in the way when the bulk of drivers are getting probed.
208 * Instead, this initcall makes sure that deferred probing is delayed until
209 * late_initcall time.
210 */
211static int deferred_probe_initcall(void)
212{
Grant Likelyd1c34142012-03-05 08:47:41 -0700213 driver_deferred_probe_enable = true;
214 driver_deferred_probe_trigger();
Grant Likelyd72cca12013-02-14 18:14:27 +0000215 /* Sort as many dependencies as possible before exiting initcalls */
Bhaktipriya Shridhar2c507e42016-08-30 22:45:34 +0530216 flush_work(&deferred_probe_work);
Grant Likelyd1c34142012-03-05 08:47:41 -0700217 return 0;
218}
219late_initcall(deferred_probe_initcall);
mochel@digitalimplant.org07e4a3e2005-03-21 10:52:54 -0800220
Tomeu Vizoso6b9cb422016-01-07 16:46:12 +0100221/**
222 * device_is_bound() - Check if device is bound to a driver
223 * @dev: device to check
224 *
225 * Returns true if passed device has already finished probing successfully
226 * against a driver.
227 *
228 * This function must be called with the device lock held.
229 */
230bool device_is_bound(struct device *dev)
231{
Rafael J. Wysocki3ded9102016-01-12 01:51:44 +0100232 return dev->p && klist_node_attached(&dev->p->knode_driver);
Tomeu Vizoso6b9cb422016-01-07 16:46:12 +0100233}
234
Kay Sievers1901fb22006-10-07 21:55:55 +0200235static void driver_bound(struct device *dev)
236{
Tomeu Vizoso6b9cb422016-01-07 16:46:12 +0100237 if (device_is_bound(dev)) {
Kay Sievers1901fb22006-10-07 21:55:55 +0200238 printk(KERN_WARNING "%s: device %s already bound\n",
Harvey Harrison2b3a3022008-03-04 16:41:05 -0800239 __func__, kobject_name(&dev->kobj));
Kay Sievers1901fb22006-10-07 21:55:55 +0200240 return;
241 }
242
Frank Rowand94f8cc02014-04-16 17:12:30 -0700243 pr_debug("driver: '%s': %s: bound to device '%s'\n", dev->driver->name,
244 __func__, dev_name(dev));
Kay Sievers1901fb22006-10-07 21:55:55 +0200245
Stefani Seiboldfbb88fa2010-03-06 17:50:14 +0100246 klist_add_tail(&dev->p->knode_driver, &dev->driver->p->klist_devices);
247
Tomeu Vizosoaa8e54b2016-01-07 16:46:14 +0100248 device_pm_check_callbacks(dev);
249
Greg Kroah-Hartman8b0372a2012-03-08 12:20:37 -0800250 /*
251 * Make sure the device is no longer in one of the deferred lists and
252 * kick off retrying all pending devices
253 */
Grant Likelyd1c34142012-03-05 08:47:41 -0700254 driver_deferred_probe_del(dev);
255 driver_deferred_probe_trigger();
256
Kay Sievers1901fb22006-10-07 21:55:55 +0200257 if (dev->bus)
Greg Kroah-Hartmanc6f7e722007-11-01 19:41:16 -0700258 blocking_notifier_call_chain(&dev->bus->p->bus_notifier,
Kay Sievers1901fb22006-10-07 21:55:55 +0200259 BUS_NOTIFY_BOUND_DRIVER, dev);
Kay Sievers1901fb22006-10-07 21:55:55 +0200260}
261
262static int driver_sysfs_add(struct device *dev)
263{
264 int ret;
265
Magnus Damm45daef02010-07-23 19:56:18 +0900266 if (dev->bus)
267 blocking_notifier_call_chain(&dev->bus->p->bus_notifier,
268 BUS_NOTIFY_BIND_DRIVER, dev);
269
Greg Kroah-Hartmane5dd1272007-11-28 15:59:15 -0800270 ret = sysfs_create_link(&dev->driver->p->kobj, &dev->kobj,
Kay Sievers1901fb22006-10-07 21:55:55 +0200271 kobject_name(&dev->kobj));
272 if (ret == 0) {
Greg Kroah-Hartmane5dd1272007-11-28 15:59:15 -0800273 ret = sysfs_create_link(&dev->kobj, &dev->driver->p->kobj,
Kay Sievers1901fb22006-10-07 21:55:55 +0200274 "driver");
275 if (ret)
Greg Kroah-Hartmane5dd1272007-11-28 15:59:15 -0800276 sysfs_remove_link(&dev->driver->p->kobj,
Kay Sievers1901fb22006-10-07 21:55:55 +0200277 kobject_name(&dev->kobj));
278 }
279 return ret;
280}
281
282static void driver_sysfs_remove(struct device *dev)
283{
284 struct device_driver *drv = dev->driver;
285
286 if (drv) {
Greg Kroah-Hartmane5dd1272007-11-28 15:59:15 -0800287 sysfs_remove_link(&drv->p->kobj, kobject_name(&dev->kobj));
Kay Sievers1901fb22006-10-07 21:55:55 +0200288 sysfs_remove_link(&dev->kobj, "driver");
289 }
290}
291
mochel@digitalimplant.org07e4a3e2005-03-21 10:52:54 -0800292/**
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800293 * device_bind_driver - bind a driver to one device.
294 * @dev: device.
mochel@digitalimplant.org07e4a3e2005-03-21 10:52:54 -0800295 *
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800296 * Allow manual attachment of a driver to a device.
297 * Caller must have already set @dev->driver.
mochel@digitalimplant.org07e4a3e2005-03-21 10:52:54 -0800298 *
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800299 * Note that this does not modify the bus reference count
300 * nor take the bus's rwsem. Please verify those are accounted
301 * for before calling this. (It is ok to call with no other effort
302 * from a driver's probe() method.)
Patrick Mochel0d3e5a22005-04-05 23:46:33 -0700303 *
Greg Kroah-Hartman8e9394c2010-02-17 10:57:05 -0800304 * This function must be called with the device lock held.
mochel@digitalimplant.org07e4a3e2005-03-21 10:52:54 -0800305 */
Andrew Mortonf86db392006-08-14 22:43:20 -0700306int device_bind_driver(struct device *dev)
mochel@digitalimplant.org07e4a3e2005-03-21 10:52:54 -0800307{
Cornelia Huckcb986b72006-11-27 10:35:12 +0100308 int ret;
309
310 ret = driver_sysfs_add(dev);
311 if (!ret)
312 driver_bound(dev);
Andy Shevchenko14b62572015-12-04 23:49:17 +0200313 else if (dev->bus)
314 blocking_notifier_call_chain(&dev->bus->p->bus_notifier,
315 BUS_NOTIFY_DRIVER_NOT_BOUND, dev);
Cornelia Huckcb986b72006-11-27 10:35:12 +0100316 return ret;
mochel@digitalimplant.org07e4a3e2005-03-21 10:52:54 -0800317}
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800318EXPORT_SYMBOL_GPL(device_bind_driver);
mochel@digitalimplant.org07e4a3e2005-03-21 10:52:54 -0800319
Greg Kroah-Hartmand7792492006-07-18 10:59:59 -0700320static atomic_t probe_count = ATOMIC_INIT(0);
Andrew Morton735a7ff2006-10-27 11:42:37 -0700321static DECLARE_WAIT_QUEUE_HEAD(probe_waitqueue);
322
Cornelia Huck21c7f302007-02-05 16:15:25 -0800323static int really_probe(struct device *dev, struct device_driver *drv)
mochel@digitalimplant.org07e4a3e2005-03-21 10:52:54 -0800324{
Strashko, Grygorii013c0742015-11-10 11:42:34 +0200325 int ret = -EPROBE_DEFER;
Grant Likely58b116b2014-04-29 12:05:22 +0100326 int local_trigger_count = atomic_read(&deferred_trigger_count);
Rob Herringbea5b152016-08-11 10:20:58 -0500327 bool test_remove = IS_ENABLED(CONFIG_DEBUG_TEST_DRIVER_REMOVE);
mochel@digitalimplant.org07e4a3e2005-03-21 10:52:54 -0800328
Strashko, Grygorii013c0742015-11-10 11:42:34 +0200329 if (defer_all_probes) {
330 /*
331 * Value of defer_all_probes can be set only by
332 * device_defer_all_probes_enable() which, in turn, will call
333 * wait_for_device_probe() right after that to avoid any races.
334 */
335 dev_dbg(dev, "Driver %s force probe deferral\n", drv->name);
336 driver_deferred_probe_add(dev);
337 return ret;
338 }
339
Greg Kroah-Hartmand7792492006-07-18 10:59:59 -0700340 atomic_inc(&probe_count);
Greg Kroah-Hartman7dc72b22007-11-28 23:49:41 -0800341 pr_debug("bus: '%s': %s: probing driver %s with device %s\n",
Kay Sievers1e0b2cf2008-10-30 01:36:48 +0100342 drv->bus->name, __func__, drv->name, dev_name(dev));
Tejun Heo9ac78492007-01-20 16:00:26 +0900343 WARN_ON(!list_empty(&dev->devres_head));
mochel@digitalimplant.org07e4a3e2005-03-21 10:52:54 -0800344
Rob Herringbea5b152016-08-11 10:20:58 -0500345re_probe:
mochel@digitalimplant.org07e4a3e2005-03-21 10:52:54 -0800346 dev->driver = drv;
Linus Walleijab780292013-01-22 10:56:14 -0700347
348 /* If using pinctrl, bind pins now before probing */
349 ret = pinctrl_bind_pins(dev);
350 if (ret)
Andy Shevchenko14b62572015-12-04 23:49:17 +0200351 goto pinctrl_bind_failed;
Linus Walleijab780292013-01-22 10:56:14 -0700352
Kay Sievers1901fb22006-10-07 21:55:55 +0200353 if (driver_sysfs_add(dev)) {
354 printk(KERN_ERR "%s: driver_sysfs_add(%s) failed\n",
Kay Sievers1e0b2cf2008-10-30 01:36:48 +0100355 __func__, dev_name(dev));
Kay Sievers1901fb22006-10-07 21:55:55 +0200356 goto probe_failed;
357 }
358
Rafael J. Wysockie90d5532015-03-20 13:59:27 +0100359 if (dev->pm_domain && dev->pm_domain->activate) {
360 ret = dev->pm_domain->activate(dev);
361 if (ret)
362 goto probe_failed;
363 }
364
Grygorii Strashko52cdbdd2015-07-27 20:43:01 +0300365 /*
366 * Ensure devices are listed in devices_kset in correct order
367 * It's important to move Dev to the end of devices_kset before
368 * calling .probe, because it could be recursive and parent Dev
369 * should always go first
370 */
371 devices_kset_move_last(dev);
372
Russell King594c8282006-01-05 14:29:51 +0000373 if (dev->bus->probe) {
374 ret = dev->bus->probe(dev);
Kay Sievers1901fb22006-10-07 21:55:55 +0200375 if (ret)
Greg Kroah-Hartmand7792492006-07-18 10:59:59 -0700376 goto probe_failed;
Russell King594c8282006-01-05 14:29:51 +0000377 } else if (drv->probe) {
Patrick Mochel0d3e5a22005-04-05 23:46:33 -0700378 ret = drv->probe(dev);
Kay Sievers1901fb22006-10-07 21:55:55 +0200379 if (ret)
Greg Kroah-Hartmand7792492006-07-18 10:59:59 -0700380 goto probe_failed;
mochel@digitalimplant.org07e4a3e2005-03-21 10:52:54 -0800381 }
Kay Sievers1901fb22006-10-07 21:55:55 +0200382
Rob Herringbea5b152016-08-11 10:20:58 -0500383 if (test_remove) {
384 test_remove = false;
385
386 if (dev->bus && dev->bus->remove)
387 dev->bus->remove(dev);
388 else if (drv->remove)
389 drv->remove(dev);
390
391 devres_release_all(dev);
392 driver_sysfs_remove(dev);
393 dev->driver = NULL;
394 dev_set_drvdata(dev, NULL);
395 if (dev->pm_domain && dev->pm_domain->dismiss)
396 dev->pm_domain->dismiss(dev);
397 pm_runtime_reinit(dev);
398
399 goto re_probe;
400 }
401
Douglas Andersonef0eebc2015-10-20 21:15:06 -0700402 pinctrl_init_done(dev);
403
Rafael J. Wysockie90d5532015-03-20 13:59:27 +0100404 if (dev->pm_domain && dev->pm_domain->sync)
405 dev->pm_domain->sync(dev);
406
Kay Sievers1901fb22006-10-07 21:55:55 +0200407 driver_bound(dev);
Patrick Mochel0d3e5a22005-04-05 23:46:33 -0700408 ret = 1;
Greg Kroah-Hartman7dc72b22007-11-28 23:49:41 -0800409 pr_debug("bus: '%s': %s: bound device %s to driver %s\n",
Kay Sievers1e0b2cf2008-10-30 01:36:48 +0100410 drv->bus->name, __func__, dev_name(dev), drv->name);
Greg Kroah-Hartmand7792492006-07-18 10:59:59 -0700411 goto done;
Patrick Mochel0d3e5a22005-04-05 23:46:33 -0700412
Greg Kroah-Hartmand7792492006-07-18 10:59:59 -0700413probe_failed:
Andy Shevchenko14b62572015-12-04 23:49:17 +0200414 if (dev->bus)
415 blocking_notifier_call_chain(&dev->bus->p->bus_notifier,
416 BUS_NOTIFY_DRIVER_NOT_BOUND, dev);
417pinctrl_bind_failed:
Tejun Heo9ac78492007-01-20 16:00:26 +0900418 devres_release_all(dev);
Kay Sievers1901fb22006-10-07 21:55:55 +0200419 driver_sysfs_remove(dev);
420 dev->driver = NULL;
Hans de Goede0998d062012-05-23 00:09:34 +0200421 dev_set_drvdata(dev, NULL);
Rafael J. Wysockie90d5532015-03-20 13:59:27 +0100422 if (dev->pm_domain && dev->pm_domain->dismiss)
423 dev->pm_domain->dismiss(dev);
Ulf Hansson5de85b92015-11-18 11:48:39 +0100424 pm_runtime_reinit(dev);
Kay Sievers1901fb22006-10-07 21:55:55 +0200425
Sergei Shtylyovbb2b4072015-01-17 22:14:41 +0300426 switch (ret) {
427 case -EPROBE_DEFER:
Grant Likelyd1c34142012-03-05 08:47:41 -0700428 /* Driver requested deferred probing */
Mark Brown13fcffb2015-03-10 11:55:49 +0000429 dev_dbg(dev, "Driver %s requests probe deferral\n", drv->name);
Grant Likelyd1c34142012-03-05 08:47:41 -0700430 driver_deferred_probe_add(dev);
Grant Likely58b116b2014-04-29 12:05:22 +0100431 /* Did a trigger occur while probing? Need to re-trigger if yes */
432 if (local_trigger_count != atomic_read(&deferred_trigger_count))
433 driver_deferred_probe_trigger();
Sergei Shtylyovbb2b4072015-01-17 22:14:41 +0300434 break;
435 case -ENODEV:
436 case -ENXIO:
437 pr_debug("%s: probe of %s rejects match %d\n",
438 drv->name, dev_name(dev), ret);
439 break;
440 default:
Patrick Mochel0d3e5a22005-04-05 23:46:33 -0700441 /* driver matched but the probe failed */
442 printk(KERN_WARNING
443 "%s: probe of %s failed with error %d\n",
Kay Sievers1e0b2cf2008-10-30 01:36:48 +0100444 drv->name, dev_name(dev), ret);
Patrick Mochel0d3e5a22005-04-05 23:46:33 -0700445 }
Cornelia Huckc578abb2006-11-27 10:35:10 +0100446 /*
447 * Ignore errors returned by ->probe so that the next driver can try
448 * its luck.
449 */
450 ret = 0;
Greg Kroah-Hartmand7792492006-07-18 10:59:59 -0700451done:
Greg Kroah-Hartmand7792492006-07-18 10:59:59 -0700452 atomic_dec(&probe_count);
Andrew Morton735a7ff2006-10-27 11:42:37 -0700453 wake_up(&probe_waitqueue);
Greg Kroah-Hartmand7792492006-07-18 10:59:59 -0700454 return ret;
455}
456
457/**
458 * driver_probe_done
459 * Determine if the probe sequence is finished or not.
460 *
461 * Should somehow figure out how to use a semaphore, not an atomic variable...
462 */
463int driver_probe_done(void)
464{
Harvey Harrison2b3a3022008-03-04 16:41:05 -0800465 pr_debug("%s: probe_count = %d\n", __func__,
Greg Kroah-Hartmand7792492006-07-18 10:59:59 -0700466 atomic_read(&probe_count));
467 if (atomic_read(&probe_count))
468 return -EBUSY;
469 return 0;
470}
471
472/**
Arjan van de Ven216773a2009-02-14 01:59:06 +0100473 * wait_for_device_probe
474 * Wait for device probing to be completed.
Arjan van de Ven216773a2009-02-14 01:59:06 +0100475 */
Ming Leib23530e2009-02-21 16:45:07 +0800476void wait_for_device_probe(void)
Arjan van de Ven216773a2009-02-14 01:59:06 +0100477{
Strashko, Grygorii013c0742015-11-10 11:42:34 +0200478 /* wait for the deferred probe workqueue to finish */
Bhaktipriya Shridhar2c507e42016-08-30 22:45:34 +0530479 flush_work(&deferred_probe_work);
Strashko, Grygorii013c0742015-11-10 11:42:34 +0200480
Arjan van de Ven216773a2009-02-14 01:59:06 +0100481 /* wait for the known devices to complete their probing */
Ming Leib23530e2009-02-21 16:45:07 +0800482 wait_event(probe_waitqueue, atomic_read(&probe_count) == 0);
Arjan van de Ven216773a2009-02-14 01:59:06 +0100483 async_synchronize_full();
Arjan van de Ven216773a2009-02-14 01:59:06 +0100484}
Arjan van de Vend4d52912009-04-21 13:32:54 -0700485EXPORT_SYMBOL_GPL(wait_for_device_probe);
Arjan van de Ven216773a2009-02-14 01:59:06 +0100486
487/**
Greg Kroah-Hartmand7792492006-07-18 10:59:59 -0700488 * driver_probe_device - attempt to bind device & driver together
489 * @drv: driver to bind a device to
490 * @dev: device to try to bind to the driver
491 *
Ming Lei49b420a2009-01-21 23:27:47 +0800492 * This function returns -ENODEV if the device is not registered,
André Goddard Rosaaf901ca2009-11-14 13:09:05 -0200493 * 1 if the device is bound successfully and 0 otherwise.
Greg Kroah-Hartmand7792492006-07-18 10:59:59 -0700494 *
Greg Kroah-Hartman8e9394c2010-02-17 10:57:05 -0800495 * This function must be called with @dev lock held. When called for a
496 * USB interface, @dev->parent lock must be held as well.
Rafael J. Wysockiddef08d2015-07-27 18:03:58 +0300497 *
498 * If the device has a parent, runtime-resume the parent before driver probing.
Greg Kroah-Hartmand7792492006-07-18 10:59:59 -0700499 */
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800500int driver_probe_device(struct device_driver *drv, struct device *dev)
Greg Kroah-Hartmand7792492006-07-18 10:59:59 -0700501{
Greg Kroah-Hartmand7792492006-07-18 10:59:59 -0700502 int ret = 0;
503
Alan Sternf2eaae12006-09-18 16:22:34 -0400504 if (!device_is_registered(dev))
505 return -ENODEV;
Greg Kroah-Hartmand7792492006-07-18 10:59:59 -0700506
Greg Kroah-Hartman7dc72b22007-11-28 23:49:41 -0800507 pr_debug("bus: '%s': %s: matched device %s with driver %s\n",
Kay Sievers1e0b2cf2008-10-30 01:36:48 +0100508 drv->bus->name, __func__, dev_name(dev), drv->name);
Greg Kroah-Hartmand7792492006-07-18 10:59:59 -0700509
Rafael J. Wysockiddef08d2015-07-27 18:03:58 +0300510 if (dev->parent)
511 pm_runtime_get_sync(dev->parent);
512
Rafael J. Wysocki5e928f72009-08-18 23:38:32 +0200513 pm_runtime_barrier(dev);
Cornelia Huck21c7f302007-02-05 16:15:25 -0800514 ret = really_probe(dev, drv);
Ulf Hanssonfa180eb2013-04-10 17:00:48 +0200515 pm_request_idle(dev);
Greg Kroah-Hartmand7792492006-07-18 10:59:59 -0700516
Rafael J. Wysockiddef08d2015-07-27 18:03:58 +0300517 if (dev->parent)
518 pm_runtime_put(dev->parent);
519
Patrick Mochel0d3e5a22005-04-05 23:46:33 -0700520 return ret;
mochel@digitalimplant.org07e4a3e2005-03-21 10:52:54 -0800521}
522
Dmitry Torokhov765230b2015-03-30 16:20:04 -0700523bool driver_allows_async_probing(struct device_driver *drv)
mochel@digitalimplant.org2287c322005-03-24 10:50:24 -0800524{
Luis R. Rodriguezd173a132015-03-30 16:20:06 -0700525 switch (drv->probe_type) {
526 case PROBE_PREFER_ASYNCHRONOUS:
Luis R. Rodriguezf2411da2015-03-30 16:20:05 -0700527 return true;
528
Luis R. Rodriguezd173a132015-03-30 16:20:06 -0700529 case PROBE_FORCE_SYNCHRONOUS:
530 return false;
Luis R. Rodriguezf2411da2015-03-30 16:20:05 -0700531
Luis R. Rodriguezd173a132015-03-30 16:20:06 -0700532 default:
Dmitry Torokhov80c6e142015-05-21 15:49:37 -0700533 if (module_requested_async_probing(drv->owner))
Luis R. Rodriguezd173a132015-03-30 16:20:06 -0700534 return true;
535
536 return false;
537 }
Dmitry Torokhov765230b2015-03-30 16:20:04 -0700538}
539
540struct device_attach_data {
541 struct device *dev;
542
543 /*
544 * Indicates whether we are are considering asynchronous probing or
545 * not. Only initial binding after device or driver registration
546 * (including deferral processing) may be done asynchronously, the
547 * rest is always synchronous, as we expect it is being done by
548 * request from userspace.
549 */
550 bool check_async;
551
552 /*
553 * Indicates if we are binding synchronous or asynchronous drivers.
554 * When asynchronous probing is enabled we'll execute 2 passes
555 * over drivers: first pass doing synchronous probing and second
556 * doing asynchronous probing (if synchronous did not succeed -
557 * most likely because there was no driver requiring synchronous
558 * probing - and we found asynchronous driver during first pass).
559 * The 2 passes are done because we can't shoot asynchronous
560 * probe for given device and driver from bus_for_each_drv() since
561 * driver pointer is not guaranteed to stay valid once
562 * bus_for_each_drv() iterates to the next driver on the bus.
563 */
564 bool want_async;
565
566 /*
567 * We'll set have_async to 'true' if, while scanning for matching
568 * driver, we'll encounter one that requests asynchronous probing.
569 */
570 bool have_async;
571};
572
573static int __device_attach_driver(struct device_driver *drv, void *_data)
574{
575 struct device_attach_data *data = _data;
576 struct device *dev = data->dev;
577 bool async_allowed;
Tomeu Vizoso656b8032016-02-15 09:25:06 +0100578 int ret;
Dmitry Torokhov765230b2015-03-30 16:20:04 -0700579
580 /*
581 * Check if device has already been claimed. This may
582 * happen with driver loading, device discovery/registration,
583 * and deferred probe processing happens all at once with
584 * multiple threads.
585 */
586 if (dev->driver)
587 return -EBUSY;
Ming Lei49b420a2009-01-21 23:27:47 +0800588
Tomeu Vizoso656b8032016-02-15 09:25:06 +0100589 ret = driver_match_device(drv, dev);
590 if (ret == 0) {
591 /* no match */
Ming Lei49b420a2009-01-21 23:27:47 +0800592 return 0;
Tomeu Vizoso656b8032016-02-15 09:25:06 +0100593 } else if (ret == -EPROBE_DEFER) {
594 dev_dbg(dev, "Device match requests probe deferral\n");
595 driver_deferred_probe_add(dev);
596 } else if (ret < 0) {
597 dev_dbg(dev, "Bus failed to match device: %d", ret);
598 return ret;
599 } /* ret > 0 means positive match */
Ming Lei49b420a2009-01-21 23:27:47 +0800600
Dmitry Torokhov765230b2015-03-30 16:20:04 -0700601 async_allowed = driver_allows_async_probing(drv);
602
603 if (async_allowed)
604 data->have_async = true;
605
606 if (data->check_async && async_allowed != data->want_async)
607 return 0;
608
Patrick Mochel0d3e5a22005-04-05 23:46:33 -0700609 return driver_probe_device(drv, dev);
mochel@digitalimplant.org2287c322005-03-24 10:50:24 -0800610}
611
Dmitry Torokhov765230b2015-03-30 16:20:04 -0700612static void __device_attach_async_helper(void *_dev, async_cookie_t cookie)
613{
614 struct device *dev = _dev;
615 struct device_attach_data data = {
616 .dev = dev,
617 .check_async = true,
618 .want_async = true,
619 };
620
621 device_lock(dev);
622
Rafael J. Wysockiddef08d2015-07-27 18:03:58 +0300623 if (dev->parent)
624 pm_runtime_get_sync(dev->parent);
625
Dmitry Torokhov765230b2015-03-30 16:20:04 -0700626 bus_for_each_drv(dev->bus, NULL, &data, __device_attach_driver);
627 dev_dbg(dev, "async probe completed\n");
628
629 pm_request_idle(dev);
630
Rafael J. Wysockiddef08d2015-07-27 18:03:58 +0300631 if (dev->parent)
632 pm_runtime_put(dev->parent);
633
Dmitry Torokhov765230b2015-03-30 16:20:04 -0700634 device_unlock(dev);
635
636 put_device(dev);
637}
638
Dmitry Torokhov802a87f2015-05-20 16:36:31 -0700639static int __device_attach(struct device *dev, bool allow_async)
Dmitry Torokhov765230b2015-03-30 16:20:04 -0700640{
641 int ret = 0;
642
643 device_lock(dev);
644 if (dev->driver) {
Tomeu Vizoso6b9cb422016-01-07 16:46:12 +0100645 if (device_is_bound(dev)) {
Dmitry Torokhov765230b2015-03-30 16:20:04 -0700646 ret = 1;
647 goto out_unlock;
648 }
649 ret = device_bind_driver(dev);
650 if (ret == 0)
651 ret = 1;
652 else {
653 dev->driver = NULL;
654 ret = 0;
655 }
656 } else {
657 struct device_attach_data data = {
658 .dev = dev,
659 .check_async = allow_async,
660 .want_async = false,
661 };
662
Rafael J. Wysockiddef08d2015-07-27 18:03:58 +0300663 if (dev->parent)
664 pm_runtime_get_sync(dev->parent);
665
Dmitry Torokhov765230b2015-03-30 16:20:04 -0700666 ret = bus_for_each_drv(dev->bus, NULL, &data,
667 __device_attach_driver);
668 if (!ret && allow_async && data.have_async) {
669 /*
670 * If we could not find appropriate driver
671 * synchronously and we are allowed to do
672 * async probes and there are drivers that
673 * want to probe asynchronously, we'll
674 * try them.
675 */
676 dev_dbg(dev, "scheduling asynchronous probe\n");
677 get_device(dev);
678 async_schedule(__device_attach_async_helper, dev);
679 } else {
680 pm_request_idle(dev);
681 }
Rafael J. Wysockiddef08d2015-07-27 18:03:58 +0300682
683 if (dev->parent)
684 pm_runtime_put(dev->parent);
Dmitry Torokhov765230b2015-03-30 16:20:04 -0700685 }
686out_unlock:
687 device_unlock(dev);
688 return ret;
689}
690
mochel@digitalimplant.org07e4a3e2005-03-21 10:52:54 -0800691/**
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800692 * device_attach - try to attach device to a driver.
693 * @dev: device.
mochel@digitalimplant.org07e4a3e2005-03-21 10:52:54 -0800694 *
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800695 * Walk the list of drivers that the bus has and call
696 * driver_probe_device() for each pair. If a compatible
697 * pair is found, break out and return.
Patrick Mochel0d3e5a22005-04-05 23:46:33 -0700698 *
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800699 * Returns 1 if the device was bound to a driver;
Dmitry Torokhov59a3cd72009-05-05 20:38:28 -0700700 * 0 if no matching driver was found;
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800701 * -ENODEV if the device is not registered.
Alan Sternbf74ad52005-11-17 16:54:12 -0500702 *
Greg Kroah-Hartman8e9394c2010-02-17 10:57:05 -0800703 * When called for a USB interface, @dev->parent lock must be held.
mochel@digitalimplant.org07e4a3e2005-03-21 10:52:54 -0800704 */
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800705int device_attach(struct device *dev)
mochel@digitalimplant.org07e4a3e2005-03-21 10:52:54 -0800706{
Dmitry Torokhov765230b2015-03-30 16:20:04 -0700707 return __device_attach(dev, false);
mochel@digitalimplant.org2287c322005-03-24 10:50:24 -0800708}
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800709EXPORT_SYMBOL_GPL(device_attach);
mochel@digitalimplant.org2287c322005-03-24 10:50:24 -0800710
Dmitry Torokhov765230b2015-03-30 16:20:04 -0700711void device_initial_probe(struct device *dev)
712{
713 __device_attach(dev, true);
714}
715
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800716static int __driver_attach(struct device *dev, void *data)
mochel@digitalimplant.org2287c322005-03-24 10:50:24 -0800717{
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800718 struct device_driver *drv = data;
Tomeu Vizoso656b8032016-02-15 09:25:06 +0100719 int ret;
mochel@digitalimplant.org2287c322005-03-24 10:50:24 -0800720
Patrick Mochel0d3e5a22005-04-05 23:46:33 -0700721 /*
722 * Lock device and try to bind to it. We drop the error
723 * here and always return 0, because we need to keep trying
724 * to bind to devices and some drivers will return an error
725 * simply if it didn't support the device.
726 *
727 * driver_probe_device() will spit a warning if there
728 * is an error.
729 */
730
Tomeu Vizoso656b8032016-02-15 09:25:06 +0100731 ret = driver_match_device(drv, dev);
732 if (ret == 0) {
733 /* no match */
Arjan van de Ven6cd49582008-09-14 08:32:06 -0700734 return 0;
Tomeu Vizoso656b8032016-02-15 09:25:06 +0100735 } else if (ret == -EPROBE_DEFER) {
736 dev_dbg(dev, "Device match requests probe deferral\n");
737 driver_deferred_probe_add(dev);
738 } else if (ret < 0) {
739 dev_dbg(dev, "Bus failed to match device: %d", ret);
740 return ret;
741 } /* ret > 0 means positive match */
Arjan van de Ven6cd49582008-09-14 08:32:06 -0700742
Alan Sternbf74ad52005-11-17 16:54:12 -0500743 if (dev->parent) /* Needed for USB */
Greg Kroah-Hartman8e9394c2010-02-17 10:57:05 -0800744 device_lock(dev->parent);
745 device_lock(dev);
Patrick Mochel0d3e5a22005-04-05 23:46:33 -0700746 if (!dev->driver)
747 driver_probe_device(drv, dev);
Greg Kroah-Hartman8e9394c2010-02-17 10:57:05 -0800748 device_unlock(dev);
Alan Sternbf74ad52005-11-17 16:54:12 -0500749 if (dev->parent)
Greg Kroah-Hartman8e9394c2010-02-17 10:57:05 -0800750 device_unlock(dev->parent);
Patrick Mochel0d3e5a22005-04-05 23:46:33 -0700751
mochel@digitalimplant.org07e4a3e2005-03-21 10:52:54 -0800752 return 0;
753}
754
755/**
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800756 * driver_attach - try to bind driver to devices.
757 * @drv: driver.
mochel@digitalimplant.org07e4a3e2005-03-21 10:52:54 -0800758 *
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800759 * Walk the list of devices that the bus has on it and try to
760 * match the driver with each one. If driver_probe_device()
761 * returns 0 and the @dev->driver is set, we've found a
762 * compatible pair.
mochel@digitalimplant.org07e4a3e2005-03-21 10:52:54 -0800763 */
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800764int driver_attach(struct device_driver *drv)
mochel@digitalimplant.org07e4a3e2005-03-21 10:52:54 -0800765{
Andrew Mortonf86db392006-08-14 22:43:20 -0700766 return bus_for_each_dev(drv->bus, NULL, drv, __driver_attach);
mochel@digitalimplant.org07e4a3e2005-03-21 10:52:54 -0800767}
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800768EXPORT_SYMBOL_GPL(driver_attach);
mochel@digitalimplant.org07e4a3e2005-03-21 10:52:54 -0800769
Stefan Richterab71c6f2007-06-17 11:02:12 +0200770/*
Greg Kroah-Hartman8e9394c2010-02-17 10:57:05 -0800771 * __device_release_driver() must be called with @dev lock held.
772 * When called for a USB interface, @dev->parent lock must be held as well.
mochel@digitalimplant.org07e4a3e2005-03-21 10:52:54 -0800773 */
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800774static void __device_release_driver(struct device *dev)
mochel@digitalimplant.org07e4a3e2005-03-21 10:52:54 -0800775{
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800776 struct device_driver *drv;
mochel@digitalimplant.org07e4a3e2005-03-21 10:52:54 -0800777
Alan Sternef2c5172007-11-16 11:57:28 -0500778 drv = dev->driver;
Alan Sternc95a6b02005-05-06 15:38:33 -0400779 if (drv) {
Dmitry Torokhov765230b2015-03-30 16:20:04 -0700780 if (driver_allows_async_probing(drv))
781 async_synchronize_full();
782
Rafael J. Wysockie1866b32011-04-29 00:33:45 +0200783 pm_runtime_get_sync(dev);
Rafael J. Wysocki5e928f72009-08-18 23:38:32 +0200784
Kay Sievers1901fb22006-10-07 21:55:55 +0200785 driver_sysfs_remove(dev);
Patrick Mochel0d3e5a22005-04-05 23:46:33 -0700786
Benjamin Herrenschmidt116af372006-10-25 13:44:59 +1000787 if (dev->bus)
Greg Kroah-Hartmanc6f7e722007-11-01 19:41:16 -0700788 blocking_notifier_call_chain(&dev->bus->p->bus_notifier,
Benjamin Herrenschmidt116af372006-10-25 13:44:59 +1000789 BUS_NOTIFY_UNBIND_DRIVER,
790 dev);
791
Rafael J. Wysockibaab52d2013-11-07 01:51:15 +0100792 pm_runtime_put_sync(dev);
Rafael J. Wysockie1866b32011-04-29 00:33:45 +0200793
Alan Stern0f836ca2006-03-31 11:52:25 -0500794 if (dev->bus && dev->bus->remove)
Russell King594c8282006-01-05 14:29:51 +0000795 dev->bus->remove(dev);
796 else if (drv->remove)
Patrick Mochel0d3e5a22005-04-05 23:46:33 -0700797 drv->remove(dev);
Tejun Heo9ac78492007-01-20 16:00:26 +0900798 devres_release_all(dev);
Patrick Mochel0d3e5a22005-04-05 23:46:33 -0700799 dev->driver = NULL;
Hans de Goede0998d062012-05-23 00:09:34 +0200800 dev_set_drvdata(dev, NULL);
Rafael J. Wysockie90d5532015-03-20 13:59:27 +0100801 if (dev->pm_domain && dev->pm_domain->dismiss)
802 dev->pm_domain->dismiss(dev);
Ulf Hansson5de85b92015-11-18 11:48:39 +0100803 pm_runtime_reinit(dev);
Rafael J. Wysockie90d5532015-03-20 13:59:27 +0100804
Greg Kroah-Hartman8940b4f2008-12-16 12:25:49 -0800805 klist_remove(&dev->p->knode_driver);
Tomeu Vizosoaa8e54b2016-01-07 16:46:14 +0100806 device_pm_check_callbacks(dev);
Joerg Roedel309b7d62009-04-24 14:57:00 +0200807 if (dev->bus)
808 blocking_notifier_call_chain(&dev->bus->p->bus_notifier,
809 BUS_NOTIFY_UNBOUND_DRIVER,
810 dev);
Patrick Mochel0d3e5a22005-04-05 23:46:33 -0700811 }
Alan Sternc95a6b02005-05-06 15:38:33 -0400812}
813
Stefan Richterab71c6f2007-06-17 11:02:12 +0200814/**
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800815 * device_release_driver - manually detach device from driver.
816 * @dev: device.
Stefan Richterab71c6f2007-06-17 11:02:12 +0200817 *
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800818 * Manually detach device from driver.
Greg Kroah-Hartman8e9394c2010-02-17 10:57:05 -0800819 * When called for a USB interface, @dev->parent lock must be held.
Stefan Richterab71c6f2007-06-17 11:02:12 +0200820 */
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800821void device_release_driver(struct device *dev)
Alan Sternc95a6b02005-05-06 15:38:33 -0400822{
823 /*
824 * If anyone calls device_release_driver() recursively from
825 * within their ->remove callback for the same device, they
826 * will deadlock right here.
827 */
Greg Kroah-Hartman8e9394c2010-02-17 10:57:05 -0800828 device_lock(dev);
Alan Sternc95a6b02005-05-06 15:38:33 -0400829 __device_release_driver(dev);
Greg Kroah-Hartman8e9394c2010-02-17 10:57:05 -0800830 device_unlock(dev);
mochel@digitalimplant.org07e4a3e2005-03-21 10:52:54 -0800831}
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800832EXPORT_SYMBOL_GPL(device_release_driver);
mochel@digitalimplant.org94e7b1c52005-03-21 12:25:36 -0800833
mochel@digitalimplant.org07e4a3e2005-03-21 10:52:54 -0800834/**
835 * driver_detach - detach driver from all devices it controls.
836 * @drv: driver.
837 */
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800838void driver_detach(struct device_driver *drv)
mochel@digitalimplant.org07e4a3e2005-03-21 10:52:54 -0800839{
Greg Kroah-Hartman8940b4f2008-12-16 12:25:49 -0800840 struct device_private *dev_prv;
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800841 struct device *dev;
Alan Sternc95a6b02005-05-06 15:38:33 -0400842
843 for (;;) {
Greg Kroah-Hartmane5dd1272007-11-28 15:59:15 -0800844 spin_lock(&drv->p->klist_devices.k_lock);
845 if (list_empty(&drv->p->klist_devices.k_list)) {
846 spin_unlock(&drv->p->klist_devices.k_lock);
Alan Sternc95a6b02005-05-06 15:38:33 -0400847 break;
848 }
Greg Kroah-Hartman8940b4f2008-12-16 12:25:49 -0800849 dev_prv = list_entry(drv->p->klist_devices.k_list.prev,
850 struct device_private,
851 knode_driver.n_node);
852 dev = dev_prv->device;
Alan Sternc95a6b02005-05-06 15:38:33 -0400853 get_device(dev);
Greg Kroah-Hartmane5dd1272007-11-28 15:59:15 -0800854 spin_unlock(&drv->p->klist_devices.k_lock);
Alan Sternc95a6b02005-05-06 15:38:33 -0400855
Alan Sternbf74ad52005-11-17 16:54:12 -0500856 if (dev->parent) /* Needed for USB */
Greg Kroah-Hartman8e9394c2010-02-17 10:57:05 -0800857 device_lock(dev->parent);
858 device_lock(dev);
Alan Sternc95a6b02005-05-06 15:38:33 -0400859 if (dev->driver == drv)
860 __device_release_driver(dev);
Greg Kroah-Hartman8e9394c2010-02-17 10:57:05 -0800861 device_unlock(dev);
Alan Sternbf74ad52005-11-17 16:54:12 -0500862 if (dev->parent)
Greg Kroah-Hartman8e9394c2010-02-17 10:57:05 -0800863 device_unlock(dev->parent);
Alan Sternc95a6b02005-05-06 15:38:33 -0400864 put_device(dev);
865 }
mochel@digitalimplant.org07e4a3e2005-03-21 10:52:54 -0800866}